Support for Withings Steel HR (#2831)

Co-authored-by: hrglpfrmpf <hrglpfrmpf@web.de>
Reviewed-on: https://codeberg.org/Freeyourgadget/Gadgetbridge/pulls/2831
Co-authored-by: hrglpfrmpf <hrglpfrmpf@noreply.codeberg.org>
Co-committed-by: hrglpfrmpf <hrglpfrmpf@noreply.codeberg.org>

GBDaoGenerator/src/nodomain/freeyourgadget/gadgetbridge/daogen/GBDaoGenerator.java

@@ -90,6 +90,7 @@ public class GBDaoGenerator {
         addCasioGBX100Sample(schema, user, device);
         addFitProActivitySample(schema, user, device);
         addPineTimeActivitySample(schema, user, device);
+        addWithingsSteelHRActivitySample(schema, user, device);
         addHybridHRActivitySample(schema, user, device);
         addVivomoveHrActivitySample(schema, user, device);
         addGarminFitFile(schema, user, device);
@@ -818,7 +819,7 @@ public class GBDaoGenerator {
         Property deviceId = batteryLevel.addLongProperty("deviceId").primaryKey().notNull().getProperty();
         batteryLevel.addToOne(device, deviceId);
         batteryLevel.addIntProperty("level").notNull();
-        batteryLevel.addIntProperty("batteryIndex").notNull().primaryKey();;
+        batteryLevel.addIntProperty("batteryIndex").notNull().primaryKey();
         return batteryLevel;
     }
 
@@ -847,4 +848,18 @@ public class GBDaoGenerator {
         addHeartRateProperties(activitySample);
         return activitySample;
     }
+
+    private static Entity addWithingsSteelHRActivitySample(Schema schema, Entity user, Entity device) {
+        Entity activitySample = addEntity(schema, "WithingsSteelHRActivitySample");
+        activitySample.implementsSerializable();
+        addCommonActivitySampleProperties("AbstractActivitySample", activitySample, user, device);
+        activitySample.addIntProperty("duration").notNull();
+        activitySample.addIntProperty(SAMPLE_RAW_KIND).notNull().codeBeforeGetterAndSetter(OVERRIDE);
+        activitySample.addIntProperty(SAMPLE_STEPS).notNull().codeBeforeGetterAndSetter(OVERRIDE);
+        activitySample.addIntProperty("distance").notNull();
+        activitySample.addIntProperty("calories").notNull();
+        addHeartRateProperties(activitySample);
+        activitySample.addIntProperty(SAMPLE_RAW_INTENSITY).notNull().codeBeforeGetterAndSetter(OVERRIDE);
+        return activitySample;
+    }
 }

app/src/main/AndroidManifest.xml

@@ -722,6 +722,10 @@
             android:name=".devices.qhybrid.CalibrationActivity"
             android:label="@string/qhybrid_title_calibration"
             android:parentActivityName=".devices.qhybrid.HRConfigActivity" />
+        <activity
+            android:name=".devices.withingssteelhr.WithingsCalibrationActivity"
+            android:label="@string/qhybrid_title_calibration"
+            android:parentActivityName=".devices.withingssteelhr.WithingsCalibrationActivity" />
         <activity
             android:name=".devices.qhybrid.CommuteActionsActivity"
             android:label="@string/qhybrid_pref_title_actions"

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/withingssteelhr/RotaryControl.java

@@ -0,0 +1,201 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.DashPathEffect;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.View;
+
+import nodomain.freeyourgadget.gadgetbridge.R;
+
+public class RotaryControl extends View {
+
+    public interface RotationListener {
+        void onRotation(short movementAmount);
+    }
+
+    private Path circlePath;
+
+    private int controlPointX;
+    private int controlPointY;
+
+    private int controlCenterX;
+    private int controlCenterY;
+    private int controlRadius;
+
+    private int padding;
+    private int controlPointSize;
+    private int controlPointColor;
+    private int lineColor;
+    private int lineThickness;
+    private double startAngle;
+    private double angle ;
+    private boolean isControlPointSelected = false;
+    private Paint paint = new Paint();
+    private Paint controlPointPaint = new Paint();
+    private RotationListener rotationListener;
+
+    public RotaryControl(Context context) {
+        this(context, null);
+    }
+
+    public RotaryControl(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public RotaryControl(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(context, attrs, defStyleAttr);
+    }
+
+    private void init(Context context, AttributeSet attrs, int defStyleAttr) {
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RotaryControl, defStyleAttr, 0);
+
+        startAngle = a.getFloat(R.styleable.RotaryControl_start_angle, (float) Math.PI / 2);
+        angle = startAngle;
+        controlPointSize = a.getDimensionPixelSize(R.styleable.RotaryControl_controlpoint_size, 50);
+        controlPointColor = a.getColor(R.styleable.RotaryControl_controlpoint_color, Color.GRAY);
+        lineThickness = a.getDimensionPixelSize(R.styleable.RotaryControl_line_thickness, 20);
+        lineColor = a.getColor(R.styleable.RotaryControl_line_color, Color.RED);
+        calculateAndSetPadding();
+        a.recycle();
+    }
+
+    private void calculateAndSetPadding() {
+        int totalPadding = getPaddingLeft() + getPaddingRight() + getPaddingBottom() + getPaddingTop() + getPaddingEnd() + getPaddingStart();
+        padding = totalPadding / 6;
+    }
+
+    @Override
+    protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
+        int smallerDim = width > height ? height : width;
+        int largestCenteredSquareLeft = (width - smallerDim) / 2;
+        int largestCenteredSquareTop = (height - smallerDim) / 2;
+        int largestCenteredSquareRight = largestCenteredSquareLeft + smallerDim;
+        int largestCenteredSquareBottom = largestCenteredSquareTop + smallerDim;
+        controlCenterX = largestCenteredSquareRight / 2 + (width - largestCenteredSquareRight) / 2;
+        controlCenterY = largestCenteredSquareBottom / 2 + (height - largestCenteredSquareBottom) / 2;
+        controlRadius = smallerDim / 2 - lineThickness / 2 - padding;
+
+        super.onSizeChanged(width, height, oldWidth, oldHeight);
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+
+        drawRotationCircle(canvas);
+        drawControlPoint(canvas);
+
+    }
+
+    private void drawControlPoint(Canvas canvas) {
+        controlPointX = (int) (controlCenterX + controlRadius * Math.cos(angle));
+        controlPointY = (int) (controlCenterY - controlRadius * Math.sin(angle));
+        controlPointPaint.setColor(controlPointColor);
+        controlPointPaint.setStyle(Paint.Style.FILL);
+        controlPointPaint.setAlpha(128);
+        Path controlPointPath = new Path();
+        controlPointPath.addCircle(controlPointX, controlPointY, controlPointSize, Path.Direction.CW);
+        canvas.drawPath(controlPointPath, controlPointPaint);
+    }
+
+    private void drawRotationCircle(Canvas canvas) {
+        DashPathEffect dashPath = new DashPathEffect(new float[]{8,22}, (float)1.0);
+        paint.setPathEffect(dashPath);
+        paint.setStyle(Paint.Style.STROKE);
+        paint.setStrokeWidth(lineThickness);
+        paint.setAntiAlias(true);
+        paint.setColor(lineColor);
+        circlePath = new Path();
+        circlePath.addCircle(controlCenterX, controlCenterY, controlRadius, Path.Direction.CW);
+        canvas.drawPath(circlePath, paint);
+    }
+
+    private void updateRotationPosition(double touchX, double touchY) {
+        double distanceX = touchX - controlCenterX;
+        double distanceY = controlCenterY - touchY;
+        double c = Math.sqrt(Math.pow(distanceX, 2) + Math.pow(distanceY, 2));
+        double currentAngle = Math.acos(distanceX / c);
+        if (distanceY < 0) {
+            currentAngle = -currentAngle;
+        }
+
+        int movementAmount = (int) ((currentAngle - angle) * 100);
+
+        int i = (int) movementAmount;
+        if (movementAmount != 0) {
+            if (Math.abs(movementAmount) > 15) {
+                movementAmount /= movementAmount;
+            }
+
+            rotationListener.onRotation((short) -movementAmount);
+        }
+
+        angle = currentAngle;
+    }
+
+    public void setRotationListener(RotationListener listener) {
+        rotationListener = listener;
+    }
+
+    public void reset() {
+        angle = startAngle;
+        invalidate();
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent ev) {
+        switch (ev.getAction()) {
+            case MotionEvent.ACTION_DOWN: {
+                double x = ev.getX();
+                double y = ev.getY();
+                if (x < controlPointX + controlPointSize && x > controlPointX - controlPointSize && y < controlPointY + controlPointSize && y > controlPointY - controlPointSize) {
+                    getParent().requestDisallowInterceptTouchEvent(true);
+                    isControlPointSelected = true;
+                    updateRotationPosition(x, y);
+                }
+                break;
+            }
+
+            case MotionEvent.ACTION_MOVE: {
+                if (isControlPointSelected) {
+                    double x = ev.getX();
+                    double y = ev.getY();
+                    updateRotationPosition(x, y);
+                }
+                break;
+            }
+
+            case MotionEvent.ACTION_UP: {
+                getParent().requestDisallowInterceptTouchEvent(false);
+                isControlPointSelected = false;
+                break;
+            }
+        }
+
+        invalidate();
+        return true;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/withingssteelhr/WithingsCalibrationActivity.java

@@ -0,0 +1,159 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr;
+
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.view.MenuItem;
+import android.view.View;
+import android.widget.Button;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.R;
+import nodomain.freeyourgadget.gadgetbridge.activities.AbstractGBActivity;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+
+public class WithingsCalibrationActivity extends AbstractGBActivity {
+
+    enum Hands {
+        HOURS((short)1),
+        MINUTES((short)0),
+        ACTIVITY_TARGET((short)2);
+
+        private short code;
+        private Hands(short code) {
+            this.code = code;
+        }
+
+    }
+
+    private GBDevice device;
+    private LocalBroadcastManager localBroadcastManager;
+    private String[] calibrationAdvices = new String[3];
+    private Hands[] hands = new Hands[]{Hands.HOURS, Hands.MINUTES, Hands.ACTIVITY_TARGET};
+    private short handIndex = 0;
+    private Button previousButton;
+    private Button nextButton;
+    private Button okButton;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_withings_calibration);
+        List<GBDevice> devices = GBApplication.app().getDeviceManager().getSelectedDevices();
+        for(GBDevice device : devices){
+            if(device.getType() == DeviceType.WITHINGS_STEEL_HR ){
+                this.device = device;
+                break;
+            }
+        }
+
+        if (device == null) {
+            Toast.makeText(this, R.string.watch_not_connected, Toast.LENGTH_LONG).show();
+            finish();
+            return;
+        }
+
+        initView();
+        localBroadcastManager = LocalBroadcastManager.getInstance(this);
+        localBroadcastManager.sendBroadcast(new Intent(WithingsSteelHRDeviceSupport.START_HANDS_CALIBRATION_CMD));
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        if (localBroadcastManager != null) {
+            localBroadcastManager.sendBroadcast(new Intent(WithingsSteelHRDeviceSupport.STOP_HANDS_CALIBRATION_CMD));
+        }
+    }
+
+    private void initView() {
+
+        calibrationAdvices[0] = getString(R.string.withings_calibration_text_hours);
+        calibrationAdvices[1] = getString(R.string.withings_calibration_text_minutes);
+        calibrationAdvices[2] = getString(R.string.withings_calibration_text_activity_target);
+
+        RotaryControl rotaryControl = findViewById(R.id.rotary_control);
+        rotaryControl.setRotationListener(new RotaryControl.RotationListener() {
+            @Override
+            public void onRotation(short movementAmount) {
+                Intent calibration = new Intent(WithingsSteelHRDeviceSupport.HANDS_CALIBRATION_CMD);
+                calibration.putExtra("hand", hands[handIndex].code);
+                calibration.putExtra("movementAmount", movementAmount);
+                localBroadcastManager.sendBroadcast(calibration);
+            }
+        });
+
+        TextView textView = findViewById(R.id.withings_calibration_textview);
+        textView.setText(calibrationAdvices[0]);
+        previousButton = findViewById(R.id.withings_calibration_button_previous);
+        previousButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                handIndex--;
+                enableButtons();
+                textView.setText(calibrationAdvices[handIndex]);
+                rotaryControl.reset();
+            }
+        });
+        nextButton = findViewById(R.id.withings_calibration_button_next);
+        nextButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                handIndex++;
+                enableButtons();
+                textView.setText(calibrationAdvices[handIndex]);
+                rotaryControl.reset();
+            }
+        });
+
+        okButton = findViewById(R.id.withings_calibration_button_ok);
+        okButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                finish();
+            }
+        });
+
+        enableButtons();
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case android.R.id.home:
+                finish();
+                return true;
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+
+    private void enableButtons() {
+        nextButton.setEnabled(handIndex < 2);
+        previousButton.setEnabled(handIndex > 0);
+        okButton.setEnabled(handIndex == 2);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/withingssteelhr/WithingsSteelHRDeviceCoordinator.java

@@ -0,0 +1,175 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr;
+
+import android.app.Activity;
+import android.content.Context;
+import android.net.Uri;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import java.util.Locale;
+
+import de.greenrobot.dao.query.QueryBuilder;
+import nodomain.freeyourgadget.gadgetbridge.GBException;
+import nodomain.freeyourgadget.gadgetbridge.R;
+import nodomain.freeyourgadget.gadgetbridge.devices.AbstractDeviceCoordinator;
+import nodomain.freeyourgadget.gadgetbridge.devices.InstallHandler;
+import nodomain.freeyourgadget.gadgetbridge.devices.SampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.DaoSession;
+import nodomain.freeyourgadget.gadgetbridge.entities.Device;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySampleDao;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDeviceCandidate;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceType;
+
+public class WithingsSteelHRDeviceCoordinator extends AbstractDeviceCoordinator {
+
+    @Override
+    protected void deleteDevice(@NonNull GBDevice gbDevice, @NonNull Device device, @NonNull DaoSession session) throws GBException {
+        Long deviceId = device.getId();
+        QueryBuilder<?> qb = session.getWithingsSteelHRActivitySampleDao().queryBuilder();
+        qb.where(WithingsSteelHRActivitySampleDao.Properties.DeviceId.eq(deviceId)).buildDelete().executeDeleteWithoutDetachingEntities();
+    }
+
+    @NonNull
+    @Override
+    public DeviceType getSupportedType(GBDeviceCandidate candidate) {
+        String name = candidate.getDevice().getName();
+        if (name != null && (name.toLowerCase(Locale.ROOT).startsWith("steel") || name.toLowerCase(Locale.ROOT).startsWith("activite"))) {
+            return DeviceType.WITHINGS_STEEL_HR;
+        }
+
+        return DeviceType.UNKNOWN;
+    }
+
+    @Override
+    public int[] getSupportedDeviceSpecificSettings(GBDevice device) {
+        return new int[]{
+                R.xml.devicesettings_withingssteelhr
+        };
+    }
+
+    @Override
+    public DeviceType getDeviceType() {
+        return DeviceType.WITHINGS_STEEL_HR;
+    }
+
+    @Override
+    public int getBondingStyle(){
+        return BONDING_STYLE_BOND;
+    }
+
+
+    @Nullable
+    @Override
+    public Class<? extends Activity> getPairingActivity() {
+        return null;
+    }
+
+    @Override
+    public boolean supportsRemSleep() {
+        return true;
+    }
+
+    @Override
+    public boolean supportsActivityDataFetching() {
+        return true;
+    }
+
+    @Override
+    public boolean supportsActivityTracking() {
+        return true;
+    }
+
+    @Override
+    public boolean supportsActivityTracks() {
+        return true;
+    }
+
+    @Override
+    public SampleProvider<? extends ActivitySample> getSampleProvider(GBDevice device, DaoSession session) {
+        return new WithingsSteelHRSampleProvider(device, session);
+    }
+
+    @Override
+    public InstallHandler findInstallHandler(Uri uri, Context context) {
+        return null;
+    }
+
+    @Override
+    public boolean supportsScreenshots() {
+        return false;
+    }
+
+    @Override
+    public int getAlarmSlotCount(GBDevice gbDevice) {
+        return 3;
+    }
+
+    @Override
+    public boolean supportsAlarmDescription(GBDevice device) {
+        return true;
+    }
+
+    @Override
+    public boolean supportsSmartWakeup(GBDevice device) {
+        return true;
+    }
+
+    @Override
+    public boolean supportsHeartRateMeasurement(GBDevice device) {
+        return true;
+    }
+
+    @Override
+    public String getManufacturer() {
+        return "Withings";
+    }
+
+    @Override
+    public boolean supportsAppsManagement(GBDevice gbDevice) {
+        return false;
+    }
+
+    @Override
+    public Class<? extends Activity> getAppsManagementActivity() {
+        return null;
+    }
+
+    @Override
+    public boolean supportsCalendarEvents() {
+        return false;
+    }
+
+    @Override
+    public boolean supportsRealtimeData() {
+        return true;
+    }
+
+    @Override
+    public boolean supportsWeather() {
+        return false;
+    }
+
+    @Override
+    public boolean supportsFindDevice() {
+        return false;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/withingssteelhr/WithingsSteelHRSampleProvider.java

@@ -0,0 +1,110 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Collections;
+import java.util.List;
+
+import de.greenrobot.dao.AbstractDao;
+import de.greenrobot.dao.Property;
+import de.greenrobot.dao.query.Query;
+import de.greenrobot.dao.query.QueryBuilder;
+import de.greenrobot.dao.query.WhereCondition;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.AbstractSampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.DaoSession;
+import nodomain.freeyourgadget.gadgetbridge.entities.Device;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySampleDao;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.ActivitySampleHandler;
+
+public class WithingsSteelHRSampleProvider extends AbstractSampleProvider<WithingsSteelHRActivitySample> {
+    private static final Logger logger = LoggerFactory.getLogger(WithingsSteelHRSampleProvider.class);
+
+    public WithingsSteelHRSampleProvider(GBDevice device, DaoSession session) {
+        super(device, session);
+    }
+
+    @Override
+    public AbstractDao<WithingsSteelHRActivitySample, ?> getSampleDao() {
+        return getSession().getWithingsSteelHRActivitySampleDao();
+    }
+
+    @Nullable
+    @Override
+    protected Property getRawKindSampleProperty() {
+        return WithingsSteelHRActivitySampleDao.Properties.RawKind;
+    }
+
+    @NonNull
+    @Override
+    protected Property getTimestampSampleProperty() {
+        return WithingsSteelHRActivitySampleDao.Properties.Timestamp;
+    }
+
+    @NonNull
+    @Override
+    protected Property getDeviceIdentifierSampleProperty() {
+        return WithingsSteelHRActivitySampleDao.Properties.DeviceId;
+    }
+
+    @Override
+    public List<WithingsSteelHRActivitySample> getActivitySamples(int timestamp_from, int timestamp_to) {
+        return super.getGBActivitySamples(timestamp_from, timestamp_to, ActivityKind.TYPE_ALL);
+    }
+
+    @Override
+    public int normalizeType(int rawType) {
+        return rawType;
+    }
+
+    @Override
+    public int toRawActivityKind(int activityKind) {
+        switch (activityKind) {
+            case ActivityKind.TYPE_UNKNOWN:
+                return 0;
+            case ActivityKind.TYPE_LIGHT_SLEEP:
+                return 1;
+            case ActivityKind.TYPE_DEEP_SLEEP:
+                return 2;
+            default:
+                return activityKind;
+        }
+    }
+
+    @Override
+    public float normalizeIntensity(int rawIntensity) {
+        if (rawIntensity > 0) {
+            return (float) (Math.log(rawIntensity) / 8);
+        }
+
+        return 0;
+    }
+
+    @Override
+    public WithingsSteelHRActivitySample createActivitySample() {
+        return new WithingsSteelHRActivitySample();
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/model/DeviceType.java

@@ -138,6 +138,7 @@ public enum DeviceType {
     SUPER_CARS(530, R.drawable.ic_device_supercars, R.drawable.ic_device_supercars_disabled, R.string.devicetype_super_cars),
     ASTEROIDOS(540, R.drawable.ic_device_default, R.drawable.ic_device_default_disabled, R.string.devicetype_asteroidos),
     SOFLOW_SO6(550, R.drawable.ic_device_vesc, R.drawable.ic_device_vesc_disabled, R.string.devicetype_soflow_s06),
+    WITHINGS_STEEL_HR(560, R.drawable.ic_device_watchxplus, R.drawable.ic_device_watchxplus_disabled, R.string.withings_steel_hr),
     TEST(1000, R.drawable.ic_device_default, R.drawable.ic_device_default_disabled, R.string.devicetype_test);
 
     private final int key;

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/DeviceSupportFactory.java

@@ -111,6 +111,7 @@ import nodomain.freeyourgadget.gadgetbridge.service.devices.vibratissimo.Vibrati
 import nodomain.freeyourgadget.gadgetbridge.service.devices.vivomovehr.VivomoveHrSupport;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.waspos.WaspOSDeviceSupport;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.watch9.Watch9DeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.xwatch.XWatchSupport;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.zetime.ZeTimeDeviceSupport;
 import nodomain.freeyourgadget.gadgetbridge.util.GB;
@@ -375,6 +376,8 @@ public class DeviceSupportFactory {
                 return new ServiceDeviceSupport(new AsteroidOSDeviceSupport());
             case SOFLOW_SO6:
                 return new ServiceDeviceSupport(new SoFlowSupport());
+            case WITHINGS_STEEL_HR:
+                return new ServiceDeviceSupport(new WithingsSteelHRDeviceSupport());
             case VIVOMOVE_HR:
                 return new ServiceDeviceSupport(new VivomoveHrSupport());
         }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/btle/TransactionBuilder.java

@@ -26,6 +26,8 @@ import org.slf4j.LoggerFactory;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 
+import java.util.Arrays;
+
 import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.NotifyAction;
 import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.ReadAction;
 import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.RequestConnectionPriorityAction;
@@ -61,6 +63,18 @@ public class TransactionBuilder {
         return add(action);
     }
 
+    public TransactionBuilder writeChunkedData(BluetoothGattCharacteristic characteristic, byte[] data, int chunkSize) {
+        for (int start = 0; start < data.length; start += chunkSize) {
+            int end = start + chunkSize;
+            if (end > data.length) end = data.length;
+            WriteAction action = new WriteAction(characteristic, Arrays.copyOfRange(data, start, end));
+            add(action);
+        }
+
+        return this;
+    }
+
+    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
     public TransactionBuilder requestMtu(int mtu){
         return add(
                 new RequestMtuAction(mtu)

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/AuthenticationHandler.java

@@ -0,0 +1,128 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr;
+
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.os.Build;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+import java.util.Random;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.WithingsUUID;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.AbstractResponseHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.Challenge;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ChallengeResponse;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.Probe;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ProbeOsVersion;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ProbeReply;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+
+public class AuthenticationHandler extends AbstractResponseHandler {
+    private static final Logger logger = LoggerFactory.getLogger(AuthenticationHandler.class);
+
+    // TODO: Save this somewhere if we actually decide to use te secret for more security:
+    private final String secret = "2EM5zNP37QzM00hmP6BFTD92nG15XwNd";
+    private WithingsSteelHRDeviceSupport support;
+    private Challenge challengeToSend;
+
+    public AuthenticationHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+        this.support = support;
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        short messageType = response.getType();
+        if (messageType == WithingsMessageType.PROBE) {
+            handleProbeReply(response);
+        } else if (messageType == WithingsMessageType.CHALLENGE) {
+            handleChallenge(response);
+        } else {
+            logger.warn("Received unkown message: " + messageType + ", will ignore this.");
+        }
+    }
+
+    private void handleChallenge(Message challengeMessage) {
+        try {
+            Challenge challenge = getTypeFromReply(Challenge.class, challengeMessage);
+            ChallengeResponse challengeResponse = new ChallengeResponse();
+            challengeResponse.setResponse(createResponse(challenge));
+            Message message = new WithingsMessage(WithingsMessageType.CHALLENGE);
+            message.addDataStructure(challengeResponse);
+            challengeToSend = new Challenge();
+            challengeToSend.setMacAddress(challenge.getMacAddress());
+            byte[] bArr = new byte[16];
+            new Random().nextBytes(bArr);
+            challengeToSend.setChallenge(bArr);
+            message.addDataStructure(challengeToSend);
+            support.sendToDevice(message);
+        } catch (Exception e) {
+            logger.error("Failed to create response to challenge: " + e.getMessage());
+        }
+    }
+
+    private void handleProbeReply(Message message) {
+        ProbeReply probeReply = getTypeFromReply(ProbeReply.class, message);
+        if (probeReply == null) {
+            throw new IllegalArgumentException("Message does not contain the required datastructure ProbeReply");
+        }
+
+        ChallengeResponse response = getTypeFromReply(ChallengeResponse.class, message);
+
+        if (response == null || Arrays.equals(response.getResponse(), createResponse(challengeToSend))) {
+            support.getDevice().setFirmwareVersion(String.valueOf(probeReply.getFirmwareVersion()));
+        } else {
+            throw new SecurityException("Response is not the one expected!");
+        }
+
+        support.onAuthenticationFinished();
+    }
+
+    private byte[] createResponse(Challenge challenge) {
+        try {
+            ByteBuffer allocate = ByteBuffer.allocate(challenge.getChallenge().length + challenge.getMacAddress().getBytes().length + secret.getBytes().length);
+            allocate.put(challenge.getChallenge());
+            allocate.put(challenge.getMacAddress().getBytes());
+            allocate.put(secret.getBytes());
+            return MessageDigest.getInstance("SHA1").digest(allocate.array());
+        } catch (NoSuchAlgorithmException e) {
+            logger.error("Failed to create response to challenge: " + e.getMessage());
+        }
+
+        return new byte[0];
+    }
+
+    private <T extends WithingsStructure> T getTypeFromReply(Class<T> type, Message message) {
+        for (WithingsStructure structure : message.getDataStructures()) {
+            if (type.isInstance(structure)) {
+                return (T)structure;
+            }
+        }
+
+        return null;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/IconHelper.java

@@ -0,0 +1,71 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr;
+
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.Icon;
+
+import nodomain.freeyourgadget.gadgetbridge.util.BitmapUtil;
+
+public class IconHelper {
+
+    public static byte[] getIconBytesFromDrawable(Drawable drawable) {
+        Bitmap bitmap = BitmapUtil.toBitmap(drawable);
+        Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, 22, 24, true);
+        int size = scaledBitmap.getRowBytes() * scaledBitmap.getHeight();
+        return toByteArray(scaledBitmap);
+    }
+
+    public static byte[] toByteArray(Bitmap bitmap) {
+        int width = bitmap.getWidth();
+        int height = bitmap.getHeight();
+        int bytesPerColumn = getBytesPerColumn(height);
+        byte[] rawData = new byte[bytesPerColumn * width];
+        for (int col = 0; col < width; col++) {
+            for (int row = 0; row < height; row++) {
+                int pixel = bitmap.getPixel(col, row);
+                if (shouldPixelbeAdded(pixel)) {
+                    int bitIndex = bytesPerColumn * col + row / 8;
+                    rawData[bitIndex] = setBit(rawData[bitIndex], row);
+                }
+            }
+        }
+
+        return rawData;
+    }
+
+    private static boolean shouldPixelbeAdded(int pixel) {
+        double luma = ((Color.red(pixel) * 0.2126d) + (Color.green(pixel) * 0.7152d) + (Color.blue(pixel) * 0.0722d)) * (Color.alpha(pixel) / 255.0f);
+        return luma > 0;
+    }
+
+    private static byte setBit(byte bits, int position) {
+        bits |= 1 << (position % 8);
+        return bits;
+    }
+
+    private static int getBytesPerColumn(int rowCount) {
+        int result = (int) rowCount / 8;
+        if (result * 8 < rowCount) {
+            result++;
+        }
+
+        return result;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/WithingsSteelHRDeviceSupport.java

@@ -0,0 +1,725 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr;
+
+import static nodomain.freeyourgadget.gadgetbridge.GBApplication.getContext;
+
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattDescriptor;
+import android.bluetooth.BluetoothGattService;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.SharedPreferences;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.widget.Toast;
+
+import androidx.annotation.NonNull;
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.R;
+import nodomain.freeyourgadget.gadgetbridge.activities.SettingsActivity;
+import nodomain.freeyourgadget.gadgetbridge.devices.hplus.HPlusConstants;
+import nodomain.freeyourgadget.gadgetbridge.devices.huami.HuamiConst;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityUser;
+import nodomain.freeyourgadget.gadgetbridge.model.Alarm;
+import nodomain.freeyourgadget.gadgetbridge.model.CalendarEventSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.CallSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.NotificationSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.NotificationType;
+import nodomain.freeyourgadget.gadgetbridge.model.WeatherSpec;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.AbstractBTLEDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.GattService;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.ServerTransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.SetDeviceStateAction;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.WithingsActivityType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.WithingsServerAction;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.WithingsUUID;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.ActivitySampleHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.BatteryStateHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.Conversation;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.ConversationQueue;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.HeartRateHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.ResponseHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.SetupFinishedHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.SimpleConversation;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.SyncFinishedHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation.WorkoutScreenListHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivityTarget;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.AlarmName;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.AlarmSettings;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.AlarmStatus;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.AncsStatus;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.DataStructureFactory;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.EndOfTransmission;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.GetActivitySamples;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageMetaData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.Locale;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.MoveHand;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.Probe;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ProbeOsVersion;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ScreenSettings;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.Time;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.TypeVersion;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.User;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.UserUnit;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.UserUnitConstants;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WorkoutScreen;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.ExpectedResponse;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.MessageBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.MessageFactory;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.SimpleHexToByteMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming.IncomingMessageHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming.IncomingMessageHandlerFactory;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming.LiveWorkoutHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification.GetNotificationAttributes;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification.GetNotificationAttributesResponse;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification.NotificationProvider;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification.NotificationSource;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+import nodomain.freeyourgadget.gadgetbridge.util.GBPrefs;
+import nodomain.freeyourgadget.gadgetbridge.util.Prefs;
+import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
+
+public class WithingsSteelHRDeviceSupport extends AbstractBTLEDeviceSupport {
+
+    private static final Logger logger = LoggerFactory.getLogger(WithingsSteelHRDeviceSupport.class);
+    public static final String LAST_ACTIVITY_SYNC = "lastActivitySync";
+    public static final String HANDS_CALIBRATION_CMD = "withings_hands_calibration";
+    public static final String START_HANDS_CALIBRATION_CMD = "start_withings_hands_calibration";
+    public static final String STOP_HANDS_CALIBRATION_CMD = "stop_withings_hands_calibration";
+    private static Prefs prefs = GBApplication.getPrefs();
+    private MessageBuilder messageBuilder;
+    private LiveWorkoutHandler liveWorkoutHandler;
+    private ActivitySampleHandler activitySampleHandler;
+    private ConversationQueue conversationQueue;
+    private boolean firstTimeConnect;
+    private BluetoothGattCharacteristic notificationSourceCharacteristic;
+    private BluetoothGattCharacteristic dataSourceCharacteristic;
+    private BluetoothDevice device;
+    private boolean syncInProgress;
+    private ActivityUser activityUser;
+    private NotificationProvider notificationProvider;
+    private IncomingMessageHandlerFactory incomingMessageHandlerFactory;
+    private final BroadcastReceiver commandReceiver;
+    private int mtuSize = 115;
+
+    public WithingsSteelHRDeviceSupport() {
+        super(logger);
+        notificationProvider = NotificationProvider.getInstance(this);
+        messageBuilder = new MessageBuilder(this, new MessageFactory(new DataStructureFactory()));
+        liveWorkoutHandler = new LiveWorkoutHandler(this);
+        incomingMessageHandlerFactory = IncomingMessageHandlerFactory.getInstance(this);
+        addSupportedService(WithingsUUID.WITHINGS_SERVICE_UUID);
+        addSupportedService(GattService.UUID_SERVICE_GENERIC_ACCESS);
+        addSupportedService(GattService.UUID_SERVICE_GENERIC_ATTRIBUTE);
+        addANCSService();
+        activityUser = new ActivityUser();
+
+        IntentFilter commandFilter = new IntentFilter(HANDS_CALIBRATION_CMD);
+        commandFilter.addAction(START_HANDS_CALIBRATION_CMD);
+        commandFilter.addAction(STOP_HANDS_CALIBRATION_CMD);
+        commandReceiver = new BroadcastReceiver() {
+
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                if (intent.getAction() == null) {
+                    return;
+                }
+
+                switch (intent.getAction()) {
+                    case HANDS_CALIBRATION_CMD:
+                        MoveHand moveHand = new MoveHand();
+                        moveHand.setHand(intent.getShortExtra("hand", (short)1));
+                        moveHand.setMovement(intent.getShortExtra("movementAmount", (short)1));
+                        sendToDevice(new WithingsMessage(WithingsMessageType.MOVE_HAND, moveHand));
+                        break;
+                    case START_HANDS_CALIBRATION_CMD:
+                        sendToDevice(new WithingsMessage(WithingsMessageType.START_HANDS_CALIBRATION));
+                        break;
+                    case STOP_HANDS_CALIBRATION_CMD:
+                        sendToDevice(new WithingsMessage(WithingsMessageType.STOP_HANDS_CALIBRATION));
+                        break;
+                }
+            }
+        };
+
+        LocalBroadcastManager.getInstance(GBApplication.getContext()).registerReceiver(commandReceiver, commandFilter);
+    }
+
+    @Override
+    public boolean getSendWriteRequestResponse() {
+        return true;
+    }
+
+
+    @Override
+    protected TransactionBuilder initializeDevice(TransactionBuilder builder) {
+        logger.debug("Starting initialization...");
+        conversationQueue = new ConversationQueue(this);
+        builder.add(new SetDeviceStateAction(getDevice(), GBDevice.State.INITIALIZING, getContext()));
+        getDevice().setFirmwareVersion("N/A");
+        getDevice().setFirmwareVersion2("N/A");
+        BluetoothGattCharacteristic characteristic = getCharacteristic(WithingsUUID.WITHINGS_WRITE_CHARACTERISTIC_UUID);
+        builder.notify(characteristic, true);
+        logger.debug("Requesting change of MTU...");
+        builder.requestMtu(119);
+        return builder;
+    }
+
+    @Override
+    public boolean connectFirstTime() {
+        firstTimeConnect = true;
+        return connect();
+    }
+
+    @Override
+    public void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {
+        logger.debug("MTU has changed to " + mtu);
+        mtuSize = mtu;
+        if (firstTimeConnect) {
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.INITIAL_CONNECT));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_LOCALE, new Locale("de")));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.START_HANDS_CALIBRATION));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.STOP_HANDS_CALIBRATION));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_TIME, new Time()));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_USER_UNIT, new UserUnit(UserUnitConstants.DISTANCE, getUnit())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_USER_UNIT, new UserUnit(UserUnitConstants.CLOCK_MODE, getTimeMode())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ACTIVITY_TARGET, new ActivityTarget(activityUser.getStepsGoal())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ANCS_STATUS));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ANCS_STATUS, new AncsStatus(true)));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_BATTERY_STATUS), new BatteryStateHandler(this));
+            addScreenListCommands();
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SETUP_FINISHED), new SetupFinishedHandler(this));
+        } else {
+            Message message = new WithingsMessage(WithingsMessageType.PROBE);
+            message.addDataStructure(new Probe((short) 1, (short) 1, 5100401));
+            message.addDataStructure(new ProbeOsVersion((short) Build.VERSION.SDK_INT));
+            conversationQueue.clear();
+            addSimpleConversationToQueue(message, new AuthenticationHandler(this));
+        }
+
+        if (!firstTimeConnect) {
+            finishInitialization();
+        }
+        conversationQueue.send();
+    }
+
+    public void doSync() {
+        activitySampleHandler = new ActivitySampleHandler(this);
+        conversationQueue.clear();
+        try {
+            if (syncInProgress || !shoudSync()) {
+                return;
+            }
+
+            getDevice().setBusyTask("Syncing");
+            syncInProgress = true;
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.INITIAL_CONNECT));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ANCS_STATUS));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_BATTERY_STATUS), new BatteryStateHandler(this));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_TIME, new Time()));
+            WithingsMessage message = new WithingsMessage(WithingsMessageType.SET_USER);
+            message.addDataStructure(getUser());
+            // The UserSecret appears in the original communication with the HealthMate app. Until now GB works without the secret.
+            // This makes the "authentication" far easier. However if it turns out that this is needed, we would need to find a way to savely store a unique generated secret.
+            //  message.addDataStructure(new UserSecret());
+            addSimpleConversationToQueue(message);
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ACTIVITY_TARGET, new ActivityTarget(activityUser.getStepsGoal())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_USER_UNIT, new UserUnit(UserUnitConstants.DISTANCE, getUnit())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_USER_UNIT, new UserUnit(UserUnitConstants.CLOCK_MODE, getTimeMode())));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ALARM_SETTINGS));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_SCREEN_SETTINGS));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ALARM));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ALARM_ENABLED));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_WORKOUT_SCREEN_LIST), new WorkoutScreenListHandler(this));
+            Calendar c = Calendar.getInstance();
+            c.setTimeInMillis(getLastSyncTimestamp());
+            message = new WithingsMessage(WithingsMessageType.GET_ACTIVITY_SAMPLES, ExpectedResponse.EOT);
+            message.addDataStructure(new GetActivitySamples(c.getTimeInMillis() / 1000, (short) 0));
+            addSimpleConversationToQueue(message, activitySampleHandler);
+            message = new WithingsMessage(WithingsMessageType.GET_MOVEMENT_SAMPLES, ExpectedResponse.EOT);
+            message.addDataStructure(new GetActivitySamples(c.getTimeInMillis() / 1000, (short) 0));
+            message.addDataStructure(new TypeVersion());
+            addSimpleConversationToQueue(message, activitySampleHandler);
+            message = new WithingsMessage(WithingsMessageType.GET_HEARTRATE_SAMPLES, ExpectedResponse.EOT);
+            message.addDataStructure(new GetActivitySamples(c.getTimeInMillis() / 1000, (short) 0));
+            message.addDataStructure(new TypeVersion());
+            addSimpleConversationToQueue(message, activitySampleHandler);
+        } catch (Exception e) {
+            logger.error("Could not synchronize! ", e);
+            conversationQueue.clear();
+        } finally {
+            // This must be done in all cases or the watch won't respond anymore!
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SYNC_OK), new SyncFinishedHandler(this));
+        }
+        conversationQueue.send();
+    }
+
+
+    @Override
+    public boolean onCharacteristicChanged(BluetoothGatt gatt,
+                                           BluetoothGattCharacteristic characteristic) {
+        if (super.onCharacteristicChanged(gatt, characteristic)) {
+            return true;
+        }
+
+        byte[] data = characteristic.getValue();
+
+        boolean complete = messageBuilder.buildMessage(data);
+        if (complete) {
+            Message message = messageBuilder.getMessage();
+            if (message.isIncomingMessage()) {
+                logger.debug("received incoming message: " + message.getType());
+                IncomingMessageHandler handler = incomingMessageHandlerFactory.getHandler(message);
+                handler.handleMessage(message);
+            } else {
+                conversationQueue.processResponse(message);
+            }
+        }
+
+        return true;
+    }
+
+    @Override
+    public void onSetCallState(CallSpec callSpec) {
+        if (callSpec.command == CallSpec.CALL_INCOMING) {
+            NotificationSpec notificationSpec = new NotificationSpec();
+            notificationSpec.sourceAppId = "incoming.call";
+            notificationSpec.title = callSpec.number;
+            notificationSpec.sender = callSpec.name;
+            notificationSpec.type = NotificationType.GENERIC_PHONE;
+            notificationProvider.notifyClient(notificationSpec);
+        } else {
+            logger.info("Received yet unhandled call command: " + callSpec.command);
+        }
+    }
+
+    @Override
+    public void onNotification(NotificationSpec notificationSpec) {
+        notificationProvider.notifyClient(notificationSpec);
+    }
+
+    @Override
+    public void onSetAlarms(ArrayList<? extends Alarm> alarms) {
+        if (alarms.size() > 3) {
+            throw new IllegalArgumentException("Steel HR does only have three alarmslots!");
+        }
+
+        if (alarms.size() == 0) {
+            return;
+        }
+
+        boolean noAlarmsEnabled = true;
+        conversationQueue.clear();
+        addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ALARM));
+        for (Alarm alarm : alarms) {
+            if (alarm.getEnabled() && !alarm.getUnused()) {
+                noAlarmsEnabled = false;
+                addAlarm(alarm);
+            }
+        }
+
+        if (noAlarmsEnabled) {
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ALARM_ENABLED, new AlarmStatus(false)));
+        }
+
+        conversationQueue.send();
+    }
+
+    @Override
+    public boolean onDescriptorWriteRequest(BluetoothDevice device, int requestId, BluetoothGattDescriptor descriptor, boolean preparedWrite, boolean responseNeeded, int offset, byte[] value) {
+        this.device = device;
+        return true;
+    }
+
+    @Override
+    public boolean onCharacteristicWriteRequest(BluetoothDevice device, int requestId, BluetoothGattCharacteristic characteristic, boolean preparedWrite, boolean responseNeeded, int offset, byte[] value) {
+        if (characteristic.getUuid().equals(WithingsUUID.CONTROL_POINT_CHARACTERISTIC_UUID)) {
+            logger.debug("Got GetNotificationAttributesRequest: " + GB.hexdump(value));
+            GetNotificationAttributes request = new GetNotificationAttributes();
+            request.deserialize(value);
+            notificationProvider.handleNotificationAttributeRequest(request);
+        }
+
+        return true;
+    }
+
+    @Override
+    public void onFetchRecordedData(int dataTypes) {
+        doSync();
+    }
+
+    @Override
+    public void onHeartRateTest() {
+        conversationQueue.clear();
+        addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_HR), new HeartRateHandler(this));
+        conversationQueue.send();
+    }
+
+    @Override
+    public void onSendConfiguration(String config) {
+        try {
+            switch (config) {
+                case HuamiConst.PREF_WORKOUT_ACTIVITY_TYPES_SORTABLE:
+                    setWorkoutActivityTypes();
+                    break;
+                default:
+                    logger.debug("unknown configuration setting received: " + config);
+            }
+        } catch (Exception e) {
+            GB.toast("Error setting configuration", Toast.LENGTH_LONG, GB.ERROR, e);
+        }
+    }
+
+    @Override
+    public void onTestNewFunction() {
+        String hexMessage = "0105080015050900111006040102030507000000000000000000";
+        conversationQueue.clear();
+        addSimpleConversationToQueue(new SimpleHexToByteMessage(hexMessage));
+        conversationQueue.send();
+    }
+
+    @Override
+    public boolean useAutoConnect() {
+        return false;
+    }
+
+    public void sendToDevice(Message message) {
+        if (message == null) {
+            return;
+        }
+
+        try {
+            TransactionBuilder builder = createTransactionBuilder("conversation");
+            builder.setCallback(this);
+            BluetoothGattCharacteristic characteristic = getCharacteristic(WithingsUUID.WITHINGS_WRITE_CHARACTERISTIC_UUID);
+            if (characteristic == null) {
+                logger.info("Characteristic with UUID " + WithingsUUID.WITHINGS_WRITE_CHARACTERISTIC_UUID + " not found.");
+                return;
+            }
+
+            byte[] rawData = message.getRawData();
+            builder.writeChunkedData(characteristic, rawData, mtuSize - 4);
+            builder.queue(getQueue());
+        } catch (Exception e) {
+            logger.warn("Could not send message because of " + e.getMessage());
+        }
+    }
+
+    public void sendAncsNotificationSourceNotification(NotificationSource notificationSource) {
+        try {
+            ServerTransactionBuilder builder = performServer("notificationSourceNotification");
+            notificationSourceCharacteristic.setValue(notificationSource.serialize());
+            builder.add(new WithingsServerAction(device, notificationSourceCharacteristic));
+            builder.queue(getQueue());
+        } catch (IOException e) {
+            logger.error("Could not send notification.", e);
+            GB.toast("Could not send notification.", Toast.LENGTH_LONG, GB.ERROR, e);
+        }
+    }
+
+    public void sendAncsDataSourceNotification(GetNotificationAttributesResponse response) {
+        try {
+            ServerTransactionBuilder builder = performServer("dataSourceNotification");
+            byte[] data = response.serialize();
+            dataSourceCharacteristic.setValue(response.serialize());
+            builder.add(new WithingsServerAction(device, dataSourceCharacteristic));
+            builder.queue(getQueue());
+        } catch (IOException e) {
+            logger.error("Could not send notification.", e);
+            GB.toast("Could not send notification.", Toast.LENGTH_LONG, GB.ERROR, e);
+        }
+    }
+
+    public void finishInitialization() {
+        TransactionBuilder builder = createTransactionBuilder("setupFinished");
+        builder.add(new SetDeviceStateAction(getDevice(), GBDevice.State.INITIALIZED, getContext()));
+        builder.queue(getQueue());
+        logger.debug("Finished initialization.");
+    }
+
+    public void finishSync() {
+        syncInProgress = false;
+        if (getDevice().isBusy()) {
+            getDevice().unsetBusyTask();
+            getDevice().sendDeviceUpdateIntent(getContext());
+        }
+        activitySampleHandler.onSyncFinished();
+        saveLastSyncTimestamp(new Date().getTime());
+    }
+
+    void onAuthenticationFinished() {
+        if (!firstTimeConnect) {
+            addScreenListCommands();
+            doSync();
+        } else {
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ANCS_STATUS, new AncsStatus(true)));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_ANCS_STATUS));
+            addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.GET_BATTERY_STATUS), new BatteryStateHandler(this));
+            conversationQueue.send();
+        }
+    }
+
+    private void addAlarm(Alarm alarm) {
+        AlarmSettings alarmSettings = new AlarmSettings();
+        alarmSettings.setHour((short) alarm.getHour());
+        alarmSettings.setMinute((short) alarm.getMinute());
+        alarmSettings.setDayOfWeek(mapRepetitionToWithingsValue(alarm));
+        if (alarm.getSmartWakeup()) {
+            // Healthmate has the possibility to change the minutecount, in GB we use a fixed value of 15
+            alarmSettings.setSmartWakeupMinutes((short) 15);
+        }
+
+        Message alarmMessage = new WithingsMessage(WithingsMessageType.SET_ALARM, alarmSettings);
+        if (!StringUtils.isEmpty(alarm.getTitle())) {
+            AlarmName alarmName = new AlarmName(alarm.getTitle());
+            alarmMessage.addDataStructure(alarmName);
+        }
+
+        addSimpleConversationToQueue(alarmMessage);
+        addSimpleConversationToQueue(new WithingsMessage(WithingsMessageType.SET_ALARM_ENABLED, new AlarmStatus(true)));
+    }
+
+    private short mapRepetitionToWithingsValue(Alarm alarm) {
+        int repetition = 0;
+        if (alarm.getRepetition(Alarm.ALARM_MON)) {
+            repetition += 0x02;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_TUE)) {
+            repetition += 0x04;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_WED)) {
+            repetition += 0x08;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_THU)) {
+            repetition += 0x10;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_FRI)) {
+            repetition += 0x20;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_SAT)) {
+            repetition += 0x40;
+        }
+        if (alarm.getRepetition(Alarm.ALARM_SUN)) {
+            repetition += 0x01;
+        }
+
+        return (short)(repetition + 0x80);
+    }
+
+    private void addANCSService() {
+        BluetoothGattService withingsGATTService = new BluetoothGattService(WithingsUUID.WITHINGS_ANCS_SERVICE_UUID, BluetoothGattService.SERVICE_TYPE_PRIMARY);
+        notificationSourceCharacteristic = new BluetoothGattCharacteristic(WithingsUUID.NOTIFICATION_SOURCE_CHARACTERISTIC_UUID, BluetoothGattCharacteristic.PROPERTY_NOTIFY, BluetoothGattCharacteristic.PERMISSION_READ);
+        notificationSourceCharacteristic.addDescriptor(new BluetoothGattDescriptor(WithingsUUID.CCC_DESCRIPTOR_UUID, BluetoothGattCharacteristic.PERMISSION_WRITE));
+        withingsGATTService.addCharacteristic(notificationSourceCharacteristic);
+        withingsGATTService.addCharacteristic(new BluetoothGattCharacteristic(WithingsUUID.CONTROL_POINT_CHARACTERISTIC_UUID, BluetoothGattCharacteristic.PROPERTY_WRITE, BluetoothGattCharacteristic.PERMISSION_WRITE));
+        dataSourceCharacteristic = new BluetoothGattCharacteristic(WithingsUUID.DATA_SOURCE_CHARACTERISTIC_UUID, BluetoothGattCharacteristic.PROPERTY_NOTIFY, BluetoothGattCharacteristic.PERMISSION_READ);
+        dataSourceCharacteristic.addDescriptor(new BluetoothGattDescriptor(WithingsUUID.CCC_DESCRIPTOR_UUID, BluetoothGattCharacteristic.PERMISSION_WRITE));
+        withingsGATTService.addCharacteristic(dataSourceCharacteristic);
+        addSupportedServerService(withingsGATTService);
+    }
+
+    private void addSimpleConversationToQueue(Message message) {
+        addSimpleConversationToQueue(message, null);
+    }
+
+    private void addSimpleConversationToQueue(Message message, ResponseHandler handler) {
+        Conversation conversation = new SimpleConversation(handler);
+        conversation.setRequest(message);
+        conversationQueue.addConversation(conversation);
+    }
+
+    private void saveLastSyncTimestamp(@NonNull long timestamp) {
+        SharedPreferences.Editor editor = GBApplication.getDeviceSpecificSharedPrefs(getDevice().getAddress()).edit();
+        editor.putLong(LAST_ACTIVITY_SYNC, timestamp);
+        editor.apply();
+    }
+
+    private long getLastSyncTimestamp() {
+        SharedPreferences settings = GBApplication.getDeviceSpecificSharedPrefs(getDevice().getAddress());
+        long lastSyncTime =  settings.getLong(LAST_ACTIVITY_SYNC, 0);
+        if (lastSyncTime > 0) {
+            return lastSyncTime;
+        } else {
+            Date currentDate = new Date();
+            Calendar c = Calendar.getInstance();
+            c.setTimeInMillis(currentDate.getTime());
+            c.add(Calendar.HOUR, - 10);
+            return c.getTimeInMillis();
+        }
+    }
+
+    private boolean shoudSync() {
+        long lastSynced = getLastSyncTimestamp();
+        int minuteInMillis = 60 * 1000;
+        return new Date().getTime() - lastSynced > minuteInMillis;
+    }
+
+    private User getUser() {
+        User user = new User();
+        ActivityUser activityUser = new ActivityUser();
+        user.setName(activityUser.getName());
+        user.setGender((byte) activityUser.getGender());
+        user.setHeight(activityUser.getHeightCm());
+        user.setWeight(activityUser.getWeightKg());
+        user.setBirthdate(activityUser.getUserBirthday());
+        return user;
+    }
+
+    private void addScreenListCommands() {
+        // TODO: this needs to be more reworked, at the moment for example the notification screen is always on and this is full of magic numbers that need to be identified properly:
+        Message message = new WithingsMessage(WithingsMessageType.SET_SCREEN_LIST);
+        ScreenSettings settings = new ScreenSettings();
+        settings.setId(0xff);
+        settings.setIdOnDevice((byte)6);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x3d);
+        settings.setIdOnDevice((byte)1);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x33);
+        settings.setIdOnDevice((byte)4);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x2d);
+        settings.setIdOnDevice((byte)2);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x2a);
+        settings.setIdOnDevice((byte)3);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x26);
+        settings.setIdOnDevice((byte)7);
+        message.addDataStructure(settings);
+
+        settings = new ScreenSettings();
+        settings.setId(0x39);
+        settings.setIdOnDevice((byte)9);
+        message.addDataStructure(settings);
+
+        message.addDataStructure(new EndOfTransmission());
+        addSimpleConversationToQueue(message);
+    }
+
+    private void setWorkoutActivityTypes() {
+        final SharedPreferences prefs = GBApplication.getDeviceSpecificSharedPrefs(gbDevice.getAddress());
+
+        final List<String> allActivityTypes = Arrays.asList(getContext().getResources().getStringArray(R.array.pref_withings_steel_activity_types_values));
+        final List<String> defaultActivityTypes = Arrays.asList(getContext().getResources().getStringArray(R.array.pref_withings_steel_activity_types_default));
+        final String activityTypesPref = prefs.getString("workout_activity_types_sortable", null);
+
+        final List<String> enabledActivityTypes;
+        if (activityTypesPref == null || activityTypesPref.equals("")) {
+            enabledActivityTypes = defaultActivityTypes;
+        } else {
+            enabledActivityTypes = Arrays.asList(activityTypesPref.split(","));
+        }
+
+        conversationQueue.clear();
+        for (int i = 0; i < enabledActivityTypes.size(); i++) {
+            String workoutType = enabledActivityTypes.get(i);
+            try {
+                Message message = createWorkoutScreenMessage(workoutType);
+                if (i == enabledActivityTypes.size() - 1) {
+                    message.addDataStructure(new EndOfTransmission());
+                }
+                addSimpleConversationToQueue(message);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
+        conversationQueue.send();
+    }
+
+    @NonNull
+    private Message createWorkoutScreenMessage(String workoutType) {
+        WithingsActivityType withingsActivityType = WithingsActivityType.fromPrefValue(workoutType);
+        int code = withingsActivityType.getCode();
+        Message message = new WithingsMessage(WithingsMessageType.SET_WORKOUT_SCREEN, ExpectedResponse.NONE);
+        WorkoutScreen workoutScreen = new WorkoutScreen();
+        workoutScreen.setId(code);
+        final int stringId = getContext().getResources().getIdentifier("activity_type_" + workoutType, "string", getContext().getPackageName());
+        workoutScreen.setName(getContext().getString(stringId));
+        message.addDataStructure(workoutScreen);
+
+        ImageMetaData imageMetaData = new ImageMetaData();
+        imageMetaData.setHeight((byte)24);
+        imageMetaData.setWidth((byte)22);
+        message.addDataStructure(imageMetaData);
+
+        ImageData imageData = new ImageData();
+        final int drawableId = ActivityKind.getIconId(withingsActivityType.toActivityKind());
+        Drawable drawable = getContext().getDrawable(drawableId);
+        imageData.setImageData(IconHelper.getIconBytesFromDrawable(drawable));
+        message.addDataStructure(imageData);
+
+        return message;
+    }
+
+    private short getTimeMode() {
+        GBPrefs gbPrefs = new GBPrefs(new Prefs(GBApplication.getDeviceSpecificSharedPrefs(gbDevice.getAddress())));
+        String tmode = gbPrefs.getTimeFormat();
+
+        if ("24h".equals(tmode)) {
+            return UserUnitConstants.UNIT_24H;
+        } else {
+            return UserUnitConstants.UNIT_12H;
+        }
+    }
+
+    private short getUnit() {
+        String units = prefs.getString(SettingsActivity.PREF_MEASUREMENT_SYSTEM, GBApplication.getContext().getString(R.string.p_unit_metric));
+
+        if (units.equals(GBApplication.getContext().getString(R.string.p_unit_metric))) {
+            return UserUnitConstants.UNIT_KM;
+        } else {
+            return UserUnitConstants.UNIT_MILES;
+        }
+    }
+
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/activity/ActivityEntry.java

@@ -0,0 +1,101 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity;
+
+public class ActivityEntry {
+    private int timestamp;
+    private int duration;
+    private int rawKind = -1;
+    private int heartrate;
+    private int steps;
+    private int calories;
+    private int distance;
+    private int rawIntensity;
+    private boolean isHeartrate;
+
+    public int getTimestamp() {
+        return timestamp;
+    }
+
+    public void setTimestamp(int timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public void setDuration(int duration) {
+        this.duration = duration;
+    }
+
+    public int getHeartrate() {
+        return heartrate;
+    }
+
+    public void setIsHeartrate(int heartrate) {
+        this.heartrate = heartrate;
+    }
+
+    public int getRawKind() {
+        return rawKind;
+    }
+
+    public void setRawKind(int rawKind) {
+        this.rawKind = rawKind;
+    }
+
+    public int getSteps() {
+        return steps;
+    }
+
+    public void setSteps(int steps) {
+        this.steps = steps;
+    }
+
+    public int getCalories() {
+        return calories;
+    }
+
+    public void setCalories(int calories) {
+        this.calories = calories;
+    }
+
+    public int getDistance() {
+        return distance;
+    }
+
+    public void setDistance(int distance) {
+        this.distance = distance;
+    }
+
+    public int getRawIntensity() {
+        return rawIntensity;
+    }
+
+    public void setRawIntensity(int rawIntensity) {
+        this.rawIntensity = rawIntensity;
+    }
+
+    public boolean isHeartrate() {
+        return isHeartrate;
+    }
+
+    public void setIsHeartrate(boolean heartrate) {
+        isHeartrate = heartrate;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/activity/SleepActivitySampleHelper.java

@@ -0,0 +1,93 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr.WithingsSteelHRSampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
+
+/**
+ * This class is needed for sleep tracking as the withings steel HR sends heartrate while sleeping in an extra activity.
+ * This leads to breaking the sleep session in the sleep calculation of GB.
+ */
+public class SleepActivitySampleHelper {
+
+    private static Logger logger = LoggerFactory.getLogger(SleepActivitySampleHelper.class);
+    private static int mergeCount;
+
+    public static WithingsSteelHRActivitySample mergeIfNecessary(WithingsSteelHRSampleProvider provider, WithingsSteelHRActivitySample sample) {
+        if (!shouldMerge(sample)) {
+            return sample;
+        }
+
+        WithingsSteelHRActivitySample overlappingSample = getOverlappingSample(provider, (int)sample.getTimestamp());
+        if (overlappingSample != null) {
+            sample = doMerge(overlappingSample, sample);
+        }
+
+        return sample;
+    }
+
+    private static WithingsSteelHRActivitySample getOverlappingSample(WithingsSteelHRSampleProvider provider, long timestamp) {
+        List<WithingsSteelHRActivitySample> samples = provider.getActivitySamples((int)timestamp - 500, (int)timestamp);
+        if (samples.isEmpty()) {
+            return null;
+        }
+
+        for (int i = samples.size()-1; i >= 0; i--) {
+            WithingsSteelHRActivitySample lastSample = samples.get(i);
+            if (isNotHeartRateOnly(lastSample, (int) timestamp)) {
+                return lastSample;
+            }
+        }
+
+        return null;
+    }
+
+    private static boolean isNotHeartRateOnly(WithingsSteelHRActivitySample lastSample, int timestamp) {
+        return lastSample.getRawKind() != ActivityKind.TYPE_NOT_MEASURED; // && lastSample.getTimestamp() <= timestamp && (lastSample.getTimestamp() + lastSample.getDuration()) >= timestamp);
+    }
+
+    private static boolean shouldMerge(WithingsSteelHRActivitySample sample) {
+        return sample.getSteps() == 0
+                && sample.getDistance() == 0
+                && sample.getRawKind() == -1
+                && sample.getCalories() == 0
+                && sample.getHeartRate() > 1
+                && sample.getRawIntensity() == 0;
+    }
+
+    private static WithingsSteelHRActivitySample doMerge(WithingsSteelHRActivitySample origin, WithingsSteelHRActivitySample update) {
+        WithingsSteelHRActivitySample mergeResult = new WithingsSteelHRActivitySample();
+        mergeResult.setTimestamp(update.getTimestamp());
+        mergeResult.setRawKind(origin.getRawKind());
+        mergeResult.setRawIntensity(origin.getRawIntensity());
+        mergeResult.setDuration(origin.getDuration() - (update.getTimestamp() - origin.getTimestamp()));
+        mergeResult.setDevice(origin.getDevice());
+        mergeResult.setDeviceId(origin.getDeviceId());
+        mergeResult.setUser(origin.getUser());
+        mergeResult.setUserId(origin.getUserId());
+        mergeResult.setProvider(origin.getProvider());
+        mergeResult.setHeartRate(update.getHeartRate());
+        return mergeResult;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/activity/WithingsActivityType.java

@@ -0,0 +1,168 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity;
+
+import java.util.Locale;
+
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.HuamiWorkoutScreenActivityType;
+
+public enum WithingsActivityType {
+
+    WALKING(1),
+    RUNNING(2),
+    HIKING(3),
+    BIKING(6),
+    SWIMMING(7),
+    SURFING(8),
+    KITESURFING(9),
+    WINDSURFING(10),
+    TENNIS(12),
+    PINGPONG(13),
+    SQUASH(14),
+    BADMINTON(15),
+    WEIGHTLIFTING(16),
+    GYMNASTICS(17),
+    ELLIPTICAL(18),
+    PILATES(19),
+    BASKETBALL(20),
+    SOCCER(21),
+    FOOTBALL(22),
+    RUGBY(23),
+    VOLLEYBALL(24),
+    GOLFING(227),
+    YOGA(28),
+    DANCING(29),
+    BOXING(30),
+    SKIING(34),
+    SNOWBOARDING(35),
+    ROWING(0), // The code has yet to be identified.
+    ZUMBA(188),
+    BASEBALL(191),
+    HANDBALL(192),
+    HOCKEY(193),
+    ICEHOCKEY(194),
+    CLIMBING(195),
+    ICESKATING(196),
+    RIDING(26),
+    OTHER(36);
+
+    private int code;
+
+    WithingsActivityType(int typeCode) {
+        this.code = typeCode;
+    }
+
+    public static WithingsActivityType fromCode(int withingsCode) {
+        for (WithingsActivityType type : values()) {
+            if (type.code == withingsCode) {
+                return type;
+            }
+        }
+        throw new RuntimeException("No matching WithingsActivityType for code: " + withingsCode);
+    }
+
+    public int getCode() {
+        return code;
+    }
+
+    public int toActivityKind() {
+        switch (this) {
+            case WALKING:
+                return ActivityKind.TYPE_WALKING;
+            case RUNNING:
+                return ActivityKind.TYPE_RUNNING;
+            case HIKING:
+                return ActivityKind.TYPE_HIKING;
+            case BIKING:
+                return ActivityKind.TYPE_CYCLING;
+            case SWIMMING:
+                return ActivityKind.TYPE_SWIMMING;
+            case SURFING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case KITESURFING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case WINDSURFING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case TENNIS:
+                return ActivityKind.TYPE_ACTIVITY;
+            case PINGPONG:
+                return ActivityKind.TYPE_PINGPONG;
+            case SQUASH:
+                return ActivityKind.TYPE_ACTIVITY;
+            case BADMINTON:
+                return ActivityKind.TYPE_BADMINTON;
+            case WEIGHTLIFTING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case GYMNASTICS:
+                return ActivityKind.TYPE_EXERCISE;
+            case ELLIPTICAL:
+                return ActivityKind.TYPE_ELLIPTICAL_TRAINER;
+            case PILATES:
+                return ActivityKind.TYPE_YOGA;
+            case BASKETBALL:
+                return ActivityKind.TYPE_BASKETBALL;
+            case SOCCER:
+                return ActivityKind.TYPE_SOCCER;
+            case FOOTBALL:
+                return ActivityKind.TYPE_ACTIVITY;
+            case RUGBY:
+                return ActivityKind.TYPE_ACTIVITY;
+            case VOLLEYBALL:
+                return ActivityKind.TYPE_ACTIVITY;
+            case GOLFING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case YOGA:
+                return ActivityKind.TYPE_YOGA;
+            case DANCING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case BOXING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case SKIING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case SNOWBOARDING:
+                return ActivityKind.TYPE_ACTIVITY;
+            case ROWING:
+                return ActivityKind.TYPE_ROWING_MACHINE;
+            case ZUMBA:
+                return ActivityKind.TYPE_ACTIVITY;
+            case BASEBALL:
+                return ActivityKind.TYPE_CRICKET;
+            case HANDBALL:
+                return ActivityKind.TYPE_ACTIVITY;
+            case HOCKEY:
+                return ActivityKind.TYPE_ACTIVITY;
+            case ICEHOCKEY:
+                return ActivityKind.TYPE_ACTIVITY;
+            case CLIMBING:
+                return ActivityKind.TYPE_CLIMBING;
+            case ICESKATING:
+                return ActivityKind.TYPE_ACTIVITY;
+            default:
+                return ActivityKind.TYPE_UNKNOWN;
+        }
+    }
+
+    public static WithingsActivityType fromPrefValue(final String prefValue) {
+        for (final WithingsActivityType type : values()) {
+            if (type.name().toLowerCase(Locale.ROOT).equals(prefValue.replace("_", "").toLowerCase(Locale.ROOT))) {
+                return type;
+            }
+        }
+        throw new RuntimeException("No matching WithingsActivityType for pref value: " + prefValue);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/WithingsServerAction.java

@@ -0,0 +1,43 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication;
+
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattServer;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BtLEServerAction;
+
+public class WithingsServerAction extends BtLEServerAction
+{
+    private BluetoothGattCharacteristic characteristic;
+
+    public WithingsServerAction(BluetoothDevice device, BluetoothGattCharacteristic characteristic) {
+        super(device);
+        this.characteristic = characteristic;
+    }
+
+    @Override
+    public boolean expectsResult() {
+        return false;
+    }
+
+    @Override
+    public boolean run(BluetoothGattServer server) {
+        return server.notifyCharacteristicChanged(getDevice(), characteristic, false);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/WithingsUUID.java

@@ -0,0 +1,34 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication;
+
+import java.util.UUID;
+
+public final class WithingsUUID {
+
+    public static final UUID WITHINGS_SERVICE_UUID = UUID.fromString("00000020-5749-5448-0037-000000000000");
+    public static final UUID WITHINGS_WRITE_CHARACTERISTIC_UUID = UUID.fromString("00000024-5749-5448-0037-000000000000");
+    public static final UUID WITHINGS_APP_CHARACTERISTIC_UUID = UUID.fromString("10000059-5749-5448-0037-000000000000");
+    public static final UUID WITHINGS_APP_CHARACTERISTIC2_UUID = UUID.fromString("10000028-5749-5448-0037-000000000000");
+    public static final UUID CCC_DESCRIPTOR_UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");
+    public static final UUID WITHINGS_ANCS_SERVICE_UUID = UUID.fromString("10000057-5749-5448-0037-00000000000000");
+    public static final UUID NOTIFICATION_SOURCE_CHARACTERISTIC_UUID = UUID.fromString("10000059-5749-5448-0037-00000000000000");
+    public static final UUID CONTROL_POINT_CHARACTERISTIC_UUID = UUID.fromString("10000058-5749-5448-0037-00000000000000");
+    public static final UUID DATA_SOURCE_CHARACTERISTIC_UUID = UUID.fromString("1000005a-5749-5448-0037-00000000000000");
+
+    private WithingsUUID() {}
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/AbstractConversation.java

@@ -0,0 +1,107 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructureType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public abstract class AbstractConversation implements Conversation {
+
+    private List<ConversationObserver> observers = new ArrayList();
+
+    private boolean complete;
+
+    protected Message request;
+
+    private short requestType;
+
+    protected ResponseHandler responseHandler;
+
+    public AbstractConversation(ResponseHandler responseHandler) {
+        this.responseHandler = responseHandler;
+    }
+
+    @Override
+    public void registerObserver(ConversationObserver observer) {
+        observers.add(observer);
+    }
+
+    @Override
+    public void removeObserver(ConversationObserver observer) {
+        observers.remove(observer);
+    }
+
+    @Override
+    public void setRequest(Message message) {
+        this.request = message;
+        this.requestType = message.getType();
+    }
+
+    @Override
+    public Message getRequest() {
+        return request;
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        if (response.getType() == requestType) {
+            if (request.needsResponse()) {
+                complete = true;
+            } else if (request.needsEOT()) {
+                complete = hasEOT(response);
+            }
+
+            doHandleResponse(response);
+            if (complete) {
+                notifyObservers(requestType);
+            }
+        }
+    }
+
+    @Override
+    public boolean isComplete() {
+        return complete;
+    }
+
+    protected void notifyObservers(short messageType) {
+        for (ConversationObserver observer : observers) {
+            observer.onConversationCompleted(messageType);
+        }
+    }
+
+    private boolean hasEOT(Message message) {
+        List<WithingsStructure> dataList = message.getDataStructures();
+        if (dataList != null) {
+            for (WithingsStructure strucuter :
+                    dataList) {
+                if (strucuter.getType() == WithingsStructureType.END_OF_TRANSMISSION) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    protected abstract void doSendRequest(Message message);
+
+    protected abstract void doHandleResponse(Message message);
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/AbstractResponseHandler.java

@@ -0,0 +1,30 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+
+public abstract class AbstractResponseHandler implements ResponseHandler {
+    protected GBDevice device;
+    protected WithingsSteelHRDeviceSupport support;
+
+    public AbstractResponseHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+        this.device = support.getDevice();
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/ActivitySampleHandler.java

@@ -0,0 +1,269 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr.WithingsSteelHRSampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.ActivityEntry;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.WithingsActivityType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WorkoutType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleCalories;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleCalories2;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleDuration;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleMovement;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleSleep;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivitySampleTime;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ActivityHeartrate;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructureType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class ActivitySampleHandler extends AbstractResponseHandler {
+
+    private static final Logger logger = LoggerFactory.getLogger(ActivitySampleHandler.class);
+    private ActivityEntry activityEntry;
+    private List<ActivityEntry> activityEntries = new ArrayList<>();
+    private List<ActivityEntry> heartrateEntries = new ArrayList<>();
+
+    public ActivitySampleHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        List<WithingsStructure> data = response.getDataStructures();
+        if (data !=  null) {
+            handleActivityData(data, response.getType());
+        }
+    }
+
+    public void onSyncFinished() {
+        mergeHeartrateSamplesIntoActivitySammples();
+        saveData();
+    }
+
+    private void handleActivityData(List<WithingsStructure> dataList, short activityType) {
+        for (WithingsStructure data : dataList) {
+            switch (data.getType()) {
+                case WithingsStructureType.ACTIVITY_SAMPLE_TIME:
+                    handleTimestamp(data, activityType);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_DURATION:
+                    handleDuration(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_MOVEMENT:
+                    handleMovement(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_CALORIES:
+                    handleCalories1(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_CALORIES_2:
+                    handleCalories2(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_SLEEP:
+                    handleSleep(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_WALK:
+                    handleWalk(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_RUN:
+                    handleRun(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_SWIM:
+                    handleSwim(data);
+                    break;
+                case WithingsStructureType.ACTIVITY_HR:
+                    handleHeartrate(data);
+                    break;
+                case WithingsStructureType.WORKOUT_TYPE:
+                    handleWorkoutType(data);
+                    break;
+                default:
+                    logger.info("Received yet unhandled activity data of type '" + data.getType() + "' with data '" + GB.hexdump(data.getRawData()) + "'.");
+            }
+        }
+
+        if (activityEntry != null) {
+            addToList(activityEntry);
+        }
+
+    }
+
+    private void handleTimestamp(WithingsStructure data, short activityType) {
+        if (activityEntry != null) {
+            addToList(activityEntry);
+        }
+
+        activityEntry = new ActivityEntry();
+        activityEntry.setIsHeartrate(activityType == WithingsMessageType.GET_HEARTRATE_SAMPLES);
+        activityEntry.setTimestamp((int)(((ActivitySampleTime)data).getDate().getTime()/1000));
+    }
+
+    private void handleWorkoutType(WithingsStructure data) {
+        WithingsActivityType activityType = WithingsActivityType.fromCode(((WorkoutType)data).getActivityType());
+        activityEntry.setRawKind(activityType.toActivityKind());
+    }
+
+    private void handleDuration(WithingsStructure data) {
+        activityEntry.setDuration(((ActivitySampleDuration)data).getDuration());
+    }
+
+    private void handleHeartrate(WithingsStructure data) {
+        activityEntry.setIsHeartrate(((ActivityHeartrate)data).getHeartrate());
+    }
+
+    private void handleMovement(WithingsStructure data) {
+        activityEntry.setRawKind(ActivityKind.TYPE_UNKNOWN);
+        activityEntry.setSteps(((ActivitySampleMovement)data).getSteps());
+        activityEntry.setDistance(((ActivitySampleMovement)data).getDistance());
+    }
+
+    private void handleWalk(WithingsStructure data) {
+        activityEntry.setRawKind(ActivityKind.TYPE_WALKING);
+    }
+
+    private void handleRun(WithingsStructure data) {
+        activityEntry.setRawKind(ActivityKind.TYPE_RUNNING);
+    }
+
+    private void handleSwim(WithingsStructure data) {
+        activityEntry.setRawKind(ActivityKind.TYPE_SWIMMING);
+    }
+
+    private void handleSleep(WithingsStructure data) {
+        int sleepType;
+        switch (((ActivitySampleSleep)data).getSleepType()) {
+            case 0:
+                sleepType = ActivityKind.TYPE_LIGHT_SLEEP;
+                activityEntry.setRawIntensity(10);
+                break;
+            case 2:
+                sleepType = ActivityKind.TYPE_DEEP_SLEEP;
+                activityEntry.setRawIntensity(70);
+                break;
+            case 3:
+                sleepType = ActivityKind.TYPE_REM_SLEEP;
+                activityEntry.setRawIntensity(80);
+                break;
+            default:
+                sleepType = ActivityKind.TYPE_LIGHT_SLEEP;
+                activityEntry.setRawIntensity(50);
+        }
+
+            activityEntry.setRawKind(sleepType);
+    }
+
+    private void handleCalories1(WithingsStructure data) {
+        activityEntry.setRawIntensity(((ActivitySampleCalories)data).getMet());
+        activityEntry.setCalories(((ActivitySampleCalories)data).getCalories());
+    }
+
+    private void handleCalories2(WithingsStructure data) {
+        activityEntry.setRawIntensity(((ActivitySampleCalories2)data).getMet());
+        activityEntry.setCalories(((ActivitySampleCalories2)data).getCalories());
+
+    }
+
+    private void addToList(ActivityEntry activityEntry) {
+        if (activityEntry.isHeartrate()) {
+            heartrateEntries.add(activityEntry);
+        } else {
+            activityEntries.add(activityEntry);
+        }
+    }
+
+    private void saveData() {
+        List<WithingsSteelHRActivitySample> activitySamples = new ArrayList<>();
+        for (ActivityEntry activityEntry : activityEntries) {
+            convertToSampleAndAddToList(activitySamples, activityEntry);
+        }
+        for (ActivityEntry activityEntry : heartrateEntries) {
+            convertToSampleAndAddToList(activitySamples, activityEntry);
+        }
+
+        writeToDB(activitySamples);
+    }
+
+    private void writeToDB(List<WithingsSteelHRActivitySample> activitySamples) {
+        try (DBHandler dbHandler = GBApplication.acquireDB()) {
+            Long userId = DBHelper.getUser(dbHandler.getDaoSession()).getId();
+            Long deviceId = DBHelper.getDevice(device, dbHandler.getDaoSession()).getId();
+            WithingsSteelHRSampleProvider provider = new WithingsSteelHRSampleProvider(device, dbHandler.getDaoSession());
+            for (WithingsSteelHRActivitySample sample : activitySamples) {
+                sample.setDeviceId(deviceId);
+                sample.setUserId(userId);
+            }
+            provider.addGBActivitySamples(activitySamples.toArray(new WithingsSteelHRActivitySample[0]));
+        } catch (Exception ex) {
+            logger.warn("Error saving activity data: " + ex.getLocalizedMessage());
+        }
+    }
+
+    private void mergeHeartrateSamplesIntoActivitySammples() {
+        for (ActivityEntry heartrateEntry : heartrateEntries) {
+            for (ActivityEntry activityEntry : activityEntries) {
+                if (doActivitiesOverlap(heartrateEntry, activityEntry)) {
+                    updateHeartrateEntry(heartrateEntry, activityEntry);
+                }
+            }
+        }
+    }
+
+    private boolean doActivitiesOverlap(ActivityEntry heartrateEntry, ActivityEntry activityEntry) {
+        return activityEntry.getTimestamp() <= heartrateEntry.getTimestamp()
+                && (activityEntry.getTimestamp() + activityEntry.getDuration()) >= heartrateEntry.getTimestamp();
+    }
+
+    private void updateHeartrateEntry(ActivityEntry heartRateEntry, ActivityEntry activityEntry) {
+        heartRateEntry.setRawKind(activityEntry.getRawKind());
+        heartRateEntry.setRawIntensity(activityEntry.getRawIntensity());
+        heartRateEntry.setDuration(activityEntry.getDuration() - (heartRateEntry.getTimestamp() - activityEntry.getTimestamp()));
+        // If timestamps are exactly the same and only then, the heartrate entry would overwrite the activity entry in the DB, so we set more values.
+        // If we would do so everytime, steps and so on would be multiplicated.
+        if (heartRateEntry.getTimestamp() == activityEntry.getTimestamp()) {
+            heartRateEntry.setSteps(activityEntry.getSteps());
+            heartRateEntry.setDistance(activityEntry.getDistance());
+            heartRateEntry.setCalories(activityEntry.getCalories());
+        }
+    }
+
+    private void convertToSampleAndAddToList(List<WithingsSteelHRActivitySample> activitySamples, ActivityEntry activityEntry) {
+        WithingsSteelHRActivitySample sample = new WithingsSteelHRActivitySample();
+        sample.setTimestamp(activityEntry.getTimestamp());
+        sample.setDuration(activityEntry.getDuration());
+        sample.setHeartRate(activityEntry.getHeartrate());
+        sample.setSteps(activityEntry.getSteps());
+        sample.setRawKind(activityEntry.getRawKind());
+        sample.setCalories(activityEntry.getCalories());
+        sample.setDistance(activityEntry.getDistance());
+        sample.setRawIntensity(activityEntry.getRawIntensity());
+        activitySamples.add(sample);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/BatteryStateHandler.java

@@ -0,0 +1,57 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventBatteryInfo;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.BatteryState;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.BatteryValues;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public class BatteryStateHandler extends AbstractResponseHandler {
+
+    public BatteryStateHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        handleBatteryState(response.getStructureByType(BatteryValues.class));
+    }
+
+    private void handleBatteryState(BatteryValues batteryValues) {
+        if (batteryValues == null) {
+            return;
+        }
+
+        GBDeviceEventBatteryInfo batteryInfo = new GBDeviceEventBatteryInfo();
+        batteryInfo.level = batteryValues.getPercent();
+        switch (batteryValues.getStatus()) {
+            case 0:
+                batteryInfo.state = BatteryState.BATTERY_CHARGING;
+                break;
+            case 1:
+                batteryInfo.state = BatteryState.BATTERY_LOW;
+                break;
+            default:
+                batteryInfo.state = BatteryState.BATTERY_NORMAL;
+        }
+        batteryInfo.voltage = batteryValues.getVolt();
+        support.evaluateGBDeviceEvent(batteryInfo);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/Conversation.java

@@ -0,0 +1,28 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public interface Conversation {
+    void registerObserver(ConversationObserver observer);
+    void removeObserver(ConversationObserver observer);
+    void setRequest(Message message);
+    Message getRequest();
+    void handleResponse(Message mesage);
+    boolean isComplete();
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/ConversationObserver.java

@@ -0,0 +1,21 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+public interface ConversationObserver {
+    void onConversationCompleted(short conversationType);
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/ConversationQueue.java

@@ -0,0 +1,100 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import android.bluetooth.BluetoothGattCharacteristic;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+import java.util.Deque;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.WithingsUUID;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
+
+public class ConversationQueue implements ConversationObserver
+{
+    private static final Logger logger = LoggerFactory.getLogger(WithingsSteelHRDeviceSupport.class);
+    private final LinkedList<Conversation> queue = new LinkedList<>();
+    private WithingsSteelHRDeviceSupport support;
+
+    public ConversationQueue(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    @Override
+    public void onConversationCompleted(short conversationType) {
+        queue.remove(getConversation(conversationType));
+        send();
+    }
+
+    public void clear() {
+        queue.clear();
+    }
+
+    public void send() {
+        logger.debug("Sending of queued messages has been requested.");
+        if (!queue.isEmpty()) {
+            Conversation nextInLine = queue.peek();
+            if (nextInLine!= null) {
+                logger.debug("Sending next queued message.");
+                Message request = nextInLine.getRequest();
+                support.sendToDevice(request);
+            }
+        }
+    }
+
+    public void addConversation(Conversation conversation) {
+        if (conversation == null) {
+            return;
+        }
+
+        if (conversation.getRequest().needsResponse() || conversation.getRequest().needsEOT()) {
+            queue.add(conversation);
+            conversation.registerObserver(this);
+        } else {
+            support.sendToDevice(conversation.getRequest());
+        }
+    }
+
+    public void processResponse(Message response) {
+        Conversation conversation = getConversation(response.getType());
+        if (conversation != null) {
+            conversation.handleResponse(response);
+        }
+    }
+
+    private Conversation getConversation(short requestType) {
+        for (Conversation conversation : queue) {
+            if (conversation.getRequest() != null && conversation.getRequest().getType() == requestType) {
+                return conversation;
+            }
+        }
+
+        return null;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/HeartRateHandler.java

@@ -0,0 +1,87 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import android.content.Intent;
+
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.GregorianCalendar;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr.WithingsSteelHRSampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceService;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.SleepActivitySampleHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.HeartRate;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.LiveHeartRate;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public class HeartRateHandler extends AbstractResponseHandler {
+    private static final Logger logger = LoggerFactory.getLogger(HeartRateHandler.class);
+
+    public HeartRateHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        if (response.getDataStructures().size() > 0) {
+            handleHeartRateData(response.getDataStructures().get(0));
+        }
+    }
+
+    private void handleHeartRateData(WithingsStructure structure) {
+        int heartRate = 0;
+        if (structure instanceof HeartRate) {
+            heartRate = ((HeartRate)structure).getHeartrate();
+        } else if (structure instanceof LiveHeartRate) {
+            heartRate = ((LiveHeartRate)structure).getHeartrate();
+        }
+
+        if (heartRate > 0) {
+            saveHeartRateData(heartRate);
+        }
+    }
+
+    private void saveHeartRateData(int heartRate) {
+        WithingsSteelHRActivitySample sample = new WithingsSteelHRActivitySample();
+        sample.setTimestamp((int) (GregorianCalendar.getInstance().getTimeInMillis() / 1000L));
+        sample.setHeartRate(heartRate);
+        try (DBHandler dbHandler = GBApplication.acquireDB()) {
+            Long userId = DBHelper.getUser(dbHandler.getDaoSession()).getId();
+            Long deviceId = DBHelper.getDevice(device, dbHandler.getDaoSession()).getId();
+            WithingsSteelHRSampleProvider provider = new WithingsSteelHRSampleProvider(device, dbHandler.getDaoSession());
+            sample.setDeviceId(deviceId);
+            sample.setUserId(userId);
+            sample = SleepActivitySampleHelper.mergeIfNecessary(provider, sample);
+            provider.addGBActivitySample(sample);
+            Intent intent = new Intent(DeviceService.ACTION_REALTIME_SAMPLES)
+                    .putExtra(DeviceService.EXTRA_REALTIME_SAMPLE, sample);
+            LocalBroadcastManager.getInstance(support.getContext()).sendBroadcast(intent);
+        } catch (Exception ex) {
+            logger.warn("Error saving current heart rate: " + ex.getLocalizedMessage());
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/ResponseHandler.java

@@ -0,0 +1,23 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public interface ResponseHandler {
+    void handleResponse(Message response);
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/SetupFinishedHandler.java

@@ -0,0 +1,35 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+
+public class SetupFinishedHandler extends AbstractResponseHandler {
+
+    public SetupFinishedHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        if (response.getType() == WithingsMessageType.SETUP_FINISHED) {
+            support.finishInitialization();;
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/SimpleConversation.java

@@ -0,0 +1,42 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public class SimpleConversation extends AbstractConversation {
+
+    public SimpleConversation(ResponseHandler responseHandler) {
+        super(responseHandler);
+    }
+
+    public SimpleConversation() {
+        super(null);
+    }
+
+    @Override
+    protected void doSendRequest(Message message) {
+        // Do nothing
+    }
+
+    @Override
+    protected void doHandleResponse(Message message) {
+        if (responseHandler != null) {
+            responseHandler.handleResponse(message);
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/SyncFinishedHandler.java

@@ -0,0 +1,37 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+
+public class SyncFinishedHandler extends AbstractResponseHandler {
+
+    public SyncFinishedHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+
+
+    @Override
+    public void handleResponse(Message response) {
+        if (response.getType() == WithingsMessageType.SYNC_OK) {
+            support.finishSync();
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/conversation/WorkoutScreenListHandler.java

@@ -0,0 +1,64 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.conversation;
+
+import android.content.SharedPreferences;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.WithingsActivityType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WorkoutScreenList;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public class WorkoutScreenListHandler extends AbstractResponseHandler {
+
+    public WorkoutScreenListHandler(WithingsSteelHRDeviceSupport support) {
+        super(support);
+    }
+
+    @Override
+    public void handleResponse(Message response) {
+        List<WithingsStructure> data = response.getDataStructures();
+        if (data != null && !data.isEmpty()) {
+            WorkoutScreenList screenList = (WorkoutScreenList) data.get(0);
+            saveScreenList(screenList);
+        }
+    }
+
+    private void saveScreenList(WorkoutScreenList screenList) {
+        int[] workoutIds = screenList.getWorkoutIds();
+        List<String> prefValues = new ArrayList<>();
+        for (int i = 0; i < workoutIds.length; i++) {
+            int currentId = workoutIds[i];
+            if (currentId > 0) {
+                WithingsActivityType type = WithingsActivityType.fromCode(currentId);
+                prefValues.add(type.name().toLowerCase(Locale.ROOT));
+            }
+         }
+
+        String workoutActivityTypes = String.join(",", prefValues);
+        GBDevice device = support.getDevice();
+        final SharedPreferences prefs = GBApplication.getDeviceSpecificSharedPrefs(device.getAddress());
+        prefs.edit().putString("workout_activity_types_sortable", workoutActivityTypes).apply();
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivityHeartrate.java

@@ -0,0 +1,47 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivityHeartrate extends WithingsStructure
+{
+    private int heartrate;
+
+    public int getHeartrate() {
+        return heartrate;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        heartrate = rawDataBuffer.get(0) & 0xff;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_HR;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleCalories.java

@@ -0,0 +1,54 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivitySampleCalories extends WithingsStructure {
+
+    private int calories;
+    private int met;
+
+    public int getCalories() {
+        return calories;
+    }
+
+    public int getMet() {
+        return met;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        calories = rawDataBuffer.getShort() & 65535;
+        met = rawDataBuffer.getShort() & 65535;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_CALORIES;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleCalories2.java

@@ -0,0 +1,25 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+public class ActivitySampleCalories2 extends ActivitySampleCalories {
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_CALORIES_2;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleDuration.java

@@ -0,0 +1,51 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+
+public class ActivitySampleDuration extends WithingsStructure {
+
+    private short duration;
+
+    public short getDuration() {
+        return duration;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        duration = rawDataBuffer.getShort();
+    }
+
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_DURATION;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleMovement.java

@@ -0,0 +1,69 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivitySampleMovement extends WithingsStructure {
+
+    private short steps;
+    private int distance;
+    private int asc;
+    private int desc;
+
+    public short getSteps() {
+        return steps;
+    }
+
+    public void setSteps(short steps) {
+        this.steps = steps;
+    }
+
+    public int getDistance() {
+        return distance;
+    }
+
+    public void setDistance(int distance) {
+        this.distance = distance;
+    }
+
+    @Override
+    public short getLength() {
+        return 18;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.putShort(steps);
+        buffer.putInt(distance);
+        buffer.putInt(asc);
+        buffer.putInt(desc);
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        steps = rawDataBuffer.getShort();
+        distance = rawDataBuffer.getInt();
+        asc = rawDataBuffer.getInt();
+        desc = rawDataBuffer.getInt();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_MOVEMENT;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleRun.java

@@ -0,0 +1,36 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivitySampleRun extends WithingsStructure {
+    @Override
+    public short getLength() {
+        return 0;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_RUN;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleSleep.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+
+public class ActivitySampleSleep extends WithingsStructure {
+
+    private short sleepType;
+
+    public short getSleepType() {
+        return sleepType;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        sleepType = rawDataBuffer.getShort();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_SLEEP;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleSwim.java

@@ -0,0 +1,36 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivitySampleSwim extends WithingsStructure {
+    @Override
+    public short getLength() {
+        return 0;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_SWIM;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleTime.java

@@ -0,0 +1,52 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.util.Date;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+
+public class ActivitySampleTime extends WithingsStructure {
+
+    private Date date;
+
+    public Date getDate() {
+        return date;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        long timestampInSeconds = rawDataBuffer.getInt() & 4294967295L;
+        date = new Date(timestampInSeconds * 1000);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_TIME;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleUnknown.java

@@ -0,0 +1,36 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivitySampleUnknown extends WithingsStructure {
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_UNKNOWN;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivitySampleWalk.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+
+public class ActivitySampleWalk extends WithingsStructure {
+
+    private short level;
+
+    public short getLevel() {
+        return level;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        level = (short) (rawDataBuffer.getShort() & 65535);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_SAMPLE_WALK;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ActivityTarget.java

@@ -0,0 +1,51 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ActivityTarget extends WithingsStructure {
+
+    private long targetCount;
+
+    public ActivityTarget(long targetCount) {
+        this.targetCount = targetCount;
+    }
+
+    public long getTargetCount() {
+        return targetCount;
+    }
+
+    public void setTargetCount(long targetCount) {
+        this.targetCount = targetCount;
+    }
+
+    @Override
+    public short getLength() {
+        return 12;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        rawDataBuffer.putLong(targetCount);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ACTIVITY_TARGET;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/AlarmName.java

@@ -0,0 +1,44 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+public class AlarmName extends WithingsStructure {
+
+    private String name;
+
+    public AlarmName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((name != null ? name.getBytes().length : 0) + 1 + HEADER_SIZE);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        addStringAsBytesWithLengthByte(rawDataBuffer, name);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ALARM_NAME;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/AlarmSettings.java

@@ -0,0 +1,111 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class AlarmSettings extends WithingsStructure {
+    private short hour;
+    private short minute;
+    private short dayOfWeek;
+    private short dayOfMonth;
+    private short month;
+    private short year;
+    private short smartWakeupMinutes;
+
+    public short getHour() {
+        return hour;
+    }
+
+    public void setHour(short hour) {
+        this.hour = hour;
+    }
+
+    public short getMinute() {
+        return minute;
+    }
+
+    public void setMinute(short minute) {
+        this.minute = minute;
+    }
+
+    public short getDayOfWeek() {
+        return dayOfWeek;
+    }
+
+    public void setDayOfWeek(short dayOfWeek) {
+        this.dayOfWeek = dayOfWeek;
+    }
+
+    public short getDayOfMonth() {
+        return dayOfMonth;
+    }
+
+    public void setDayOfMonth(short dayOfMonth) {
+        this.dayOfMonth = dayOfMonth;
+    }
+
+    public short getMonth() {
+        return month;
+    }
+
+    public void setMonth(short month) {
+        this.month = month;
+    }
+
+    public short getYear() {
+        return year;
+    }
+
+    public void setYear(short year) {
+        this.year = year;
+    }
+
+    public short getYetUnkown() {
+        return smartWakeupMinutes;
+    }
+
+    public void setSmartWakeupMinutes(short smartWakeupMinutes) {
+        this.smartWakeupMinutes = smartWakeupMinutes;
+    }
+
+    @Override
+    public short getLength() {
+        return 11;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put((byte)hour);
+        buffer.put((byte)minute);
+        buffer.put((byte)dayOfWeek);
+        buffer.put((byte)dayOfMonth);
+        buffer.put((byte)month);
+        buffer.put((byte)year);
+        buffer.put((byte)smartWakeupMinutes);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ALARM;
+    }
+
+    @Override
+    public boolean withEndOfMessage() {
+        return true;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/AlarmStatus.java

@@ -0,0 +1,51 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class AlarmStatus extends WithingsStructure {
+
+    private boolean enabled;
+
+    public AlarmStatus(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    @Override
+    public short getLength() {
+        return 5;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put(enabled? (byte) 1 : (byte) 0);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ALARM_STATUS;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/AncsStatus.java

@@ -0,0 +1,45 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class AncsStatus extends WithingsStructure {
+
+    private boolean isOn;
+
+    public AncsStatus() {}
+
+    public AncsStatus(boolean isOn) {
+        this.isOn = isOn;
+    }
+
+    @Override
+    public short getLength() {
+        return 5;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put(isOn? (byte)0x01 : 0x00);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.ANCS_STATUS;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/BatteryValues.java

@@ -0,0 +1,73 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+
+public class BatteryValues extends WithingsStructure {
+
+    private short percent;
+    private short status;
+    private int volt;
+
+    public short getPercent() {
+        return percent;
+    }
+
+    public void setPercent(short percent) {
+        this.percent = percent;
+    }
+
+    public short getStatus() {
+        return status;
+    }
+
+    public void setStatus(short status) {
+        this.status = status;
+    }
+
+    public int getVolt() {
+        return volt;
+    }
+
+    public void setVolt(int volt) {
+        this.volt = volt;
+    }
+
+    @Override
+    public short getLength() {
+        return 14;
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        percent = (short)(rawDataBuffer.get() & 255);
+        status = (short)(rawDataBuffer.get() & 255);
+        volt = rawDataBuffer.getInt();
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.BATTERY_STATUS;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/Challenge.java

@@ -0,0 +1,80 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+public class Challenge extends WithingsStructure {
+
+    private String macAddress;
+
+    private byte[] challenge;
+
+    public void setMacAddress(String macAddress) {
+        this.macAddress = macAddress;
+    }
+
+    public void setChallenge(byte[] challenge) {
+        this.challenge = challenge;
+    }
+
+    public String getMacAddress() {
+        return macAddress;
+    }
+
+    public byte[] getChallenge() {
+        return challenge;
+    }
+
+    @Override
+    public short getLength() {
+        int challengeLength = 0;
+        int macAddressLength = (macAddress != null ? macAddress.getBytes().length : 0) + 1;
+        if (challenge != null) {
+            challengeLength = challenge.length;
+        }
+
+        return (short) (macAddressLength + challengeLength + 5);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        addStringAsBytesWithLengthByte(buffer, macAddress);
+
+        if (challenge != null) {
+            buffer.put((byte) challenge.length);
+            buffer.put(challenge);
+        } else {
+            buffer.put((byte)0);
+        }
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        macAddress = getNextString(rawDataBuffer);
+        challenge = getNextByteArray(rawDataBuffer);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.CHALLENGE;
+    }
+
+
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ChallengeResponse.java

@@ -0,0 +1,54 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+public class ChallengeResponse extends WithingsStructure {
+
+    private byte[] response = new byte[0];
+
+    public byte[] getResponse() {
+        return response;
+    }
+
+    public void setResponse(byte[] response) {
+        this.response = response;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((response != null ? response.length : 0) + 5);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        addByteArrayWithLengthByte(buffer, response);
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        response = getNextByteArray(rawDataBuffer);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.CHALLENGE_RESPONSE;
+    }
+
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/DataStructureFactory.java

@@ -0,0 +1,168 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class DataStructureFactory {
+
+    private static final Logger logger = LoggerFactory.getLogger(DataStructureFactory.class.getSimpleName());
+    private static final int HEADER_SIZE = 4;
+
+    public List<WithingsStructure> createStructuresFromRawData(byte[] rawData) {
+        List<WithingsStructure> structures = new ArrayList<>();
+        if (rawData == null) {
+            return structures;
+        }
+
+        List<byte[]> rawDataStructures = splitRawData(rawData);
+        for (byte[] rawDataStructure : rawDataStructures) {
+            WithingsStructure structure = null;
+
+            short structureTypeFromResponse = (short) BLETypeConversions.toInt16(rawDataStructure[1], rawDataStructure[0]);
+
+            switch (structureTypeFromResponse) {
+                case WithingsStructureType.HR:
+                    structure = new HeartRate();
+                    break;
+                case WithingsStructureType.LIVE_HR:
+                    structure = new LiveHeartRate();
+                    break;
+                case WithingsStructureType.BATTERY_STATUS:
+                    structure = new BatteryValues();
+                    break;
+                case WithingsStructureType.SCREEN_SETTINGS:
+                    structure = new ScreenSettings();
+                    break;
+                case WithingsStructureType.ANCS_STATUS:
+                    structure = new AncsStatus();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_TIME:
+                    structure = new ActivitySampleTime();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_DURATION:
+                    structure = new ActivitySampleDuration();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_MOVEMENT:
+                    structure = new ActivitySampleMovement();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_CALORIES:
+                    structure = new ActivitySampleCalories();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_CALORIES_2:
+                    structure = new ActivitySampleCalories2();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_SLEEP:
+                    structure = new ActivitySampleSleep();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_WALK:
+                    structure = new ActivitySampleWalk();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_RUN:
+                    structure = new ActivitySampleRun();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_SWIM:
+                    structure = new ActivitySampleSwim();
+                    break;
+                case WithingsStructureType.ACTIVITY_HR:
+                    structure = new ActivityHeartrate();
+                    break;
+                case WithingsStructureType.PROBE_REPLY:
+                    structure = new ProbeReply();
+                    break;
+                case WithingsStructureType.CHALLENGE:
+                    structure = new Challenge();
+                    break;
+                case WithingsStructureType.CHALLENGE_RESPONSE:
+                    structure = new ChallengeResponse();
+                    break;
+                case WithingsStructureType.ACTIVITY_SAMPLE_UNKNOWN:
+                    structure = new ActivitySampleUnknown();
+                    break;
+                case WithingsStructureType.END_OF_TRANSMISSION:
+                    structure = new EndOfTransmission();
+                    break;
+                case WithingsStructureType.WORKOUT_TYPE:
+                    structure = new WorkoutType();
+                    break;
+                case WithingsStructureType.LIVE_WORKOUT_START:
+                    structure = new LiveWorkoutStart();
+                    break;
+                case WithingsStructureType.LIVE_WORKOUT_END:
+                    structure = new LiveWorkoutEnd();
+                    break;
+                case WithingsStructureType.LIVE_WORKOUT_PAUSE_STATE:
+                    structure = new LiveWorkoutPauseState();
+                    break;
+                case WithingsStructureType.WORKOUT_SCREEN_LIST:
+                    structure = new WorkoutScreenList();
+                    break;
+                case WithingsStructureType.IMAGE_META_DATA:
+                    structure = new ImageMetaData();
+                    break;
+                case WithingsStructureType.GLYPH_ID:
+                    structure = new GlyphId();
+                    break;
+                case WithingsStructureType.NOTIFICATION_APP_ID:
+                    structure = new GlyphId();
+                    break;
+                default:
+                    structure = null;
+                    logger.info("Received yet unknown structure type: " + structureTypeFromResponse);
+            }
+
+            if (structure != null) {
+                structure.fillFromRawData(removeHeaderBytes(rawDataStructure));
+                structures.add(structure);
+            }
+        }
+
+        return structures;
+    }
+
+    private List<byte[]> splitRawData(byte[] rawData) {
+        int remainingBytes = rawData.length;
+        List<byte[]> result = new ArrayList<>();
+
+        while(remainingBytes > 3) {
+            short structureLength = (short) BLETypeConversions.toInt16(rawData[3], rawData[2]);
+            remainingBytes -= (structureLength + HEADER_SIZE);
+            try {
+                result.add(Arrays.copyOfRange(rawData, 0, structureLength + HEADER_SIZE));
+                if (remainingBytes > 0) {
+                    rawData = Arrays.copyOfRange(rawData, structureLength + HEADER_SIZE, rawData.length);
+                }
+            } catch (Exception e) {
+                logger.warn("Splitting of data failed: " + GB.hexdump(rawData));
+            }
+        }
+
+        return result;
+    }
+
+    private byte[] removeHeaderBytes(byte[] data) {
+        return Arrays.copyOfRange(data, HEADER_SIZE, data.length);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/EndOfTransmission.java

@@ -0,0 +1,44 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class EndOfTransmission extends WithingsStructure {
+    @Override
+    public short getLength() {
+        return 4;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public byte[] getRawData() {
+        ByteBuffer rawDataBuffer = ByteBuffer.allocate(4);
+        rawDataBuffer.putShort(getType());
+        rawDataBuffer.putShort((short)0);
+        return rawDataBuffer.array();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.END_OF_TRANSMISSION;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/GetActivitySamples.java

@@ -0,0 +1,47 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class GetActivitySamples extends WithingsStructure {
+
+    public long timestampFrom;
+
+    public short maxSampleCount;
+
+    public GetActivitySamples(long timestampFrom, short maxSampleCount) {
+        this.timestampFrom = timestampFrom;
+        this.maxSampleCount = maxSampleCount;
+    }
+
+    @Override
+    public short getLength() {
+        return 10;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.putInt((int)(timestampFrom & 4294967295L));
+        buffer.putShort((short)maxSampleCount);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.GET_ACTIVITY_SAMPLES;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/GlyphId.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+public class GlyphId extends WithingsStructure {
+
+    private long unicode;
+
+    public long getUnicode() {
+        return unicode;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        int value = rawDataBuffer.getInt();
+        unicode = ByteBuffer.allocate(4).putInt(value).order(ByteOrder.LITTLE_ENDIAN).getInt(0);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.GLYPH_ID;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/HeartRate.java

@@ -0,0 +1,47 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class HeartRate extends WithingsStructure {
+
+    private int heartrate;
+
+    public int getHeartrate() {
+        return heartrate;
+    }
+
+    @Override
+    public short getLength() {
+        return 5;
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        heartrate = rawDataBuffer.get(1) & 0xff;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.HR;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ImageData.java

@@ -0,0 +1,47 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ImageData extends WithingsStructure {
+
+    byte [] imageData;
+
+    public void setImageData(byte[] imageData) {
+        this.imageData = imageData;
+    }
+
+    @Override
+    public short getLength() {
+        return imageData != null ? (short)(imageData.length + 1 + HEADER_SIZE) : 1 + HEADER_SIZE;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        if (imageData != null) {
+            addByteArrayWithLengthByte(buffer, imageData);
+        } else {
+            addByteArrayWithLengthByte(buffer, new byte[0]);
+        }
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.IMAGE_DATA;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ImageMetaData.java

@@ -0,0 +1,66 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ImageMetaData extends WithingsStructure {
+
+    private byte unknown = 0x00;
+    private byte width;
+    private byte height;
+
+    public byte getWidth() {
+        return width;
+    }
+
+    public void setWidth(byte width) {
+        this.width = width;
+    }
+
+    public byte getHeight() {
+        return height;
+    }
+
+    public void setHeight(byte height) {
+        this.height = height;
+    }
+
+    @Override
+    public short getLength() {
+        return 7;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put(unknown);
+        buffer.put(width);
+        buffer.put(height);
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        unknown = rawDataBuffer.get();
+        width = rawDataBuffer.get();
+        height = rawDataBuffer.get();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.IMAGE_META_DATA;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/LiveHeartRate.java

@@ -0,0 +1,48 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class LiveHeartRate extends WithingsStructure {
+
+    private int heartrate;
+
+    public int getHeartrate() {
+        return heartrate;
+    }
+
+    @Override
+    public short getLength() {
+        return 1;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        heartrate = rawDataBuffer.get() & 0xff;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.LIVE_HR;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/LiveWorkoutEnd.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.util.Date;
+
+public class LiveWorkoutEnd extends WithingsStructure {
+
+    private Date endtime;
+
+    public Date getEndtime() {
+        return endtime;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        long timestampInSeconds = rawDataBuffer.getInt() & 4294967295L;
+        endtime = new Date(timestampInSeconds * 1000);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.LIVE_WORKOUT_END;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/LiveWorkoutPauseState.java

@@ -0,0 +1,66 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.util.Date;
+
+public class LiveWorkoutPauseState extends WithingsStructure {
+
+    private byte yetunknown;
+
+    // Is always the same as long as the actual pause continues:
+    private Date starttime;
+
+    // This is just a guess, but observation show that this is quite possible the meaning of this value that is send when the pause is over
+    private int lengthInSeconds;
+
+    public Date getStarttime() {
+        return starttime;
+    }
+
+    public int getLengthInSeconds() {
+        return lengthInSeconds;
+    }
+
+    @Override
+    public short getLength() {
+        return 13;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        yetunknown = rawDataBuffer.get();
+
+        long timestampInSeconds = rawDataBuffer.getInt() & 4294967295L;
+        if (timestampInSeconds > 0) {
+            starttime = new Date(timestampInSeconds * 1000);
+        }
+
+        lengthInSeconds = rawDataBuffer.getInt();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.LIVE_WORKOUT_PAUSE_STATE;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/LiveWorkoutStart.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.util.Date;
+
+public class LiveWorkoutStart extends WithingsStructure {
+
+    private Date starttime;
+
+    public Date getStarttime() {
+        return starttime;
+    }
+
+    @Override
+    public short getLength() {
+        return 8;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        long timestampInSeconds = rawDataBuffer.getInt() & 4294967295L;
+        starttime = new Date(timestampInSeconds * 1000);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.LIVE_WORKOUT_START;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/Locale.java

@@ -0,0 +1,44 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+public class Locale extends WithingsStructure {
+
+    private String locale = "en";
+
+    public Locale(String locale) {
+        this.locale = locale;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((locale != null ? locale.getBytes().length : 0) + 1 + HEADER_SIZE);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        addStringAsBytesWithLengthByte(rawDataBuffer, locale);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.LOCALE;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/MoveHand.java

@@ -0,0 +1,49 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class MoveHand extends WithingsStructure {
+
+    private short hand;
+    private short movement;
+
+    public void setHand(short hand) {
+        this.hand = hand;
+    }
+
+    public void setMovement(short movement) {
+        this.movement = movement;
+    }
+
+    @Override
+    public short getLength() {
+        return 7;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put((byte) (hand & 255));
+        buffer.putShort(movement);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.MOVE_HAND;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/Probe.java

@@ -0,0 +1,51 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class Probe extends WithingsStructure {
+
+    private short os;
+
+    private short app;
+
+    private long version;
+
+    public Probe(short os, short app, long version) {
+        this.os = os;
+        this.app = app;
+        this.version = version;
+    }
+
+    @Override
+    public short getLength() {
+        return 10;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put((byte) (os & 255));
+        buffer.put((byte) (app & 255));
+        buffer.putInt((int) (version & 4294967295L));
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.PROBE;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ProbeOsVersion.java

@@ -0,0 +1,43 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ProbeOsVersion extends WithingsStructure {
+
+    private short osVersion;
+
+    public ProbeOsVersion(short osVersion) {
+        this.osVersion = osVersion;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.putShort(osVersion);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.PROBE_OS_VERSION;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ProbeReply.java

@@ -0,0 +1,111 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.AuthenticationHandler;
+import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
+
+public class ProbeReply extends WithingsStructure {
+    private static final Logger logger = LoggerFactory.getLogger(ProbeReply.class);
+    private int yetUnknown1;
+    private String name;
+    private String mac;
+    private String secret;
+    private int yetUnknown2;
+    private String mId;
+    private int yetUnknown3;
+    private int firmwareVersion;
+    private int yetUnknown4;
+
+    public int getYetUnknown1() {
+        return yetUnknown1;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getMac() {
+        return mac;
+    }
+
+    public String getSecret() {
+        return secret;
+    }
+
+    public int getYetUnknown2() {
+        return yetUnknown2;
+    }
+
+    public String getmId() {
+        return mId;
+    }
+
+    public int getYetUnknown3() {
+        return yetUnknown3;
+    }
+
+    public int getFirmwareVersion() {
+        return firmwareVersion;
+    }
+
+    public int getYetUnknown4() {
+        return yetUnknown4;
+    }
+
+    @Override
+    public short getLength() {
+        int length = (name != null ? name.getBytes(StandardCharsets.UTF_8).length : 0) + 1;
+        length += (mac != null ? mac.getBytes().length : 0) + 1;
+        length += (secret != null ? secret.getBytes().length : 0) + 1;
+        length += (mId != null ? mId.getBytes().length : 0) + 1;
+        return (short) (length + 24);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        try {
+            yetUnknown1 = rawDataBuffer.getInt();
+            name = getNextString(rawDataBuffer);
+            mac = getNextString(rawDataBuffer);
+            secret = getNextString(rawDataBuffer);
+            yetUnknown2 = rawDataBuffer.getInt();
+            mId = getNextString(rawDataBuffer);
+            yetUnknown3 = rawDataBuffer.getInt();
+            firmwareVersion = rawDataBuffer.getInt();
+            yetUnknown4 = rawDataBuffer.getInt();
+        } catch (Exception e) {
+            logger.warn("Could not handle buffer with data " + StringUtils.bytesToHex(rawDataBuffer.array()));
+        }
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.PROBE_REPLY;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/ScreenSettings.java

@@ -0,0 +1,67 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class ScreenSettings extends WithingsStructure {
+
+    private int id;
+
+    // TODO change to an actual unique ID. Must then be changed in User too.
+    private int userId = 123456;
+    private int yetUnknown1 = 0;
+    private int yetUnknown2 = 0;
+    private byte idOnDevice;
+    private byte yetUnkown3 = 0x01;
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public byte getIdOnDevice() {
+        return idOnDevice;
+    }
+
+    public void setIdOnDevice(byte idOnDevice) {
+        this.idOnDevice = idOnDevice;
+    }
+
+    @Override
+    public short getLength() {
+        return 22;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.putInt(this.id);
+        buffer.putInt(this.userId);
+        buffer.putInt(this.yetUnknown1);
+        buffer.putInt(this.yetUnknown2);
+        buffer.put(this.idOnDevice);
+        buffer.put(this.yetUnkown3);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.SCREEN_SETTINGS;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/SourceAppId.java

@@ -0,0 +1,52 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class SourceAppId extends WithingsStructure {
+
+    private String appId;
+
+    public String getAppId() {
+        return appId;
+    }
+
+    public void setAppId(String appId) {
+        this.appId = appId;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((appId != null ? appId.getBytes().length : 0) + 5);
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        appId = getNextString(rawDataBuffer);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        addStringAsBytesWithLengthByte(buffer, appId);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.NOTIFICATION_APP_ID;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/Status.java

@@ -0,0 +1,36 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class Status extends WithingsStructure {
+    @Override
+    public short getLength() {
+        return 5;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put((byte) 0x01);
+    }
+
+    @Override
+    public short getType() {
+        return (short) 2420;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/Time.java

@@ -0,0 +1,102 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import org.threeten.bp.Instant;
+import org.threeten.bp.ZoneId;
+import org.threeten.bp.zone.ZoneOffsetTransition;
+import org.threeten.bp.zone.ZoneRules;
+
+import java.nio.ByteBuffer;
+import java.util.Date;
+import java.util.TimeZone;
+
+import ch.qos.logback.core.encoder.ByteArrayUtil;
+
+public class Time extends WithingsStructure {
+
+    private Instant now;
+    private int timeOffsetInSeconds;
+    private Instant nextDaylightSavingTransition;
+    private int nextDaylightSavingTransitionOffsetInSeconds;
+
+    public Time() {
+        now = Instant.now();
+        final TimeZone timezone = TimeZone.getDefault();
+        timeOffsetInSeconds = timezone.getOffset(now.toEpochMilli()) / 1000;
+        final ZoneId zoneId = ZoneId.systemDefault();
+        final ZoneRules zoneRules = zoneId.getRules();
+        final ZoneOffsetTransition nextTransition = zoneRules.nextTransition(Instant.now());
+        long nextTransitionTs = 0;
+        if (nextTransition != null) {
+            nextTransitionTs = nextTransition.getDateTimeBefore().atZone(zoneId).toEpochSecond();
+            nextDaylightSavingTransitionOffsetInSeconds = nextTransition.getOffsetAfter().getTotalSeconds();
+        }
+
+        nextDaylightSavingTransition = Instant.ofEpochSecond(nextTransitionTs);
+    }
+
+    public Instant getNow() {
+        return now;
+    }
+
+    public void setNow(Instant now) {
+        this.now = now;
+    }
+
+    public int getTimeOffsetInSeconds() {
+        return timeOffsetInSeconds;
+    }
+
+    public void setTimeOffsetInSeconds(int TimeOffsetInSeconds) {
+        this.timeOffsetInSeconds = TimeOffsetInSeconds;
+    }
+
+    public Instant getNextDaylightSavingTransition() {
+        return nextDaylightSavingTransition;
+    }
+
+    public void setNextDaylightSavingTransition(Instant nextDaylightSavingTransition) {
+        this.nextDaylightSavingTransition = nextDaylightSavingTransition;
+    }
+
+    public int getNextDaylightSavingTransitionOffsetInSeconds() {
+        return nextDaylightSavingTransitionOffsetInSeconds;
+    }
+
+    public void setNextDaylightSavingTransitionOffsetInSeconds(int nextDaylightSavingTransitionOffsetInSeconds) {
+        this.nextDaylightSavingTransitionOffsetInSeconds = nextDaylightSavingTransitionOffsetInSeconds;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.TIME;
+    }
+
+    @Override
+    public short getLength() {
+        return 20;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        rawDataBuffer.putInt((int)now.getEpochSecond());
+        rawDataBuffer.putInt(timeOffsetInSeconds);
+        rawDataBuffer.putInt((int)nextDaylightSavingTransition.getEpochSecond());
+        rawDataBuffer.putInt(nextDaylightSavingTransitionOffsetInSeconds);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/TypeVersion.java

@@ -0,0 +1,39 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class TypeVersion extends WithingsStructure {
+
+    private byte version = 0x01;
+
+    @Override
+    public short getLength() {
+        return 5;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put(version);
+    }
+
+    @Override
+    public short getType() {
+        return 2401;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/User.java

@@ -0,0 +1,102 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Date;
+
+public class User extends WithingsStructure {
+
+    // This is just a dummy value as this seems to be the withings account id,
+    // which we do not need, but the watch expects:
+    private int userID = 123456;
+    private int weight;
+    private int height;
+    //Seems to be 0x00 for male and 0x01 for female. Found no other in my tests.
+    private byte gender;
+    private Date birthdate;
+    private String name;
+
+    public int getUserID() {
+        return userID;
+    }
+
+    public void setUserID(int userID) {
+        this.userID = userID;
+    }
+
+    public int getWeight() {
+        return weight;
+    }
+
+    public void setWeight(int weight) {
+        this.weight = weight;
+    }
+
+    public int getHeight() {
+        return height;
+    }
+
+    public void setHeight(int height) {
+        this.height = height;
+    }
+
+    public byte getGender() {
+        return gender;
+    }
+
+    public void setGender(byte gender) {
+        this.gender = gender;
+    }
+
+    public Date getBirthdate() {
+        return birthdate;
+    }
+
+    public void setBirthdate(Date birthdate) {
+        this.birthdate = birthdate;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((name != null ? name.getBytes(StandardCharsets.UTF_8).length : 0) + 22);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        rawDataBuffer.putInt(userID);
+        rawDataBuffer.putInt(weight);
+        rawDataBuffer.putInt(height);
+        rawDataBuffer.put(gender);
+        rawDataBuffer.putInt((int)(birthdate.getTime()/1000));
+        addStringAsBytesWithLengthByte(rawDataBuffer, name);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.USER;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/UserSecret.java

@@ -0,0 +1,39 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class UserSecret extends WithingsStructure {
+
+    private String secret = "2EM5zNP37QzM00hmP6BFTD92nG15XwNd";
+
+    @Override
+    public short getLength() {
+        return 37;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        addStringAsBytesWithLengthByte(buffer, secret);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.USER_SECRET;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/UserUnit.java

@@ -0,0 +1,52 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class UserUnit extends WithingsStructure {
+
+    private byte unknown1 = 0;
+    private byte unknown2 = 0;
+    private short type;
+    private short unit;
+
+    public UserUnit() {}
+
+    public UserUnit(short type, short unit) {
+        this.type = type;
+        this.unit = unit;
+    }
+
+    @Override
+    public short getLength() {
+        return 10;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.put(unknown1);
+        buffer.put(unknown2);
+        buffer.putShort(type);
+        buffer.putShort(unit);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.USER_UNIT;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/UserUnitConstants.java

@@ -0,0 +1,29 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+public final class UserUnitConstants {
+
+    public static final short DISTANCE = 2;
+    public static final short CLOCK_MODE = 4;
+    public static final short UNIT_KM = 24;
+    public static final short UNIT_MILES = 25;
+    public static final short UNIT_24H = 26;
+    public static final short UNIT_12H = 27;
+
+    private UserUnitConstants() {}
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WithingsStructure.java

@@ -0,0 +1,103 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+/**
+ * This abstract class is the common denominator for all data structures used inside commands and the corresponding responses.
+ * @see Message
+ */
+public abstract class WithingsStructure {
+    protected final static short HEADER_SIZE = 4;
+
+    /**
+     * Some messages have some end bytes, some have not.
+     * Subclasses that need to have the eom appended need to overwrite this class and return true.
+     * The default value is false.
+     *
+     * @return true if some end of message should be appended
+     */
+    public boolean withEndOfMessage() {
+        return false;
+    }
+
+    public byte[] getRawData() {
+        short length = (getLength());
+        ByteBuffer rawDataBuffer = ByteBuffer.allocate(length);
+        rawDataBuffer.putShort(getType());
+        rawDataBuffer.putShort((short)(length - HEADER_SIZE));
+        fillinTypeSpecificData(rawDataBuffer);
+        return rawDataBuffer.array();
+    }
+
+    protected void addStringAsBytesWithLengthByte(ByteBuffer buffer, String str) {
+        if (str == null) {
+            buffer.put((byte)0);
+        } else {
+            byte[] stringAsBytes = str.getBytes(StandardCharsets.UTF_8);
+            buffer.put((byte)stringAsBytes.length);
+            buffer.put(stringAsBytes);
+        }
+    }
+
+    protected void fillFromRawData(byte[] rawData) {
+        fillFromRawDataAsBuffer(ByteBuffer.wrap(rawData));
+    };
+
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {};
+
+    public abstract short getLength();
+
+    protected abstract void fillinTypeSpecificData(ByteBuffer buffer);
+    public abstract short getType();
+
+    protected String getNextString(ByteBuffer byteBuffer) {
+        // For strings in the raw data the first byte of the data is the length of the string:
+        int stringLength = (short)(byteBuffer.get() & 255);
+        byte[] stringBytes = new byte[stringLength];
+        byteBuffer.get(stringBytes);
+        return new String(stringBytes, Charset.forName("UTF-8"));
+    }
+
+    protected byte[] getNextByteArray(ByteBuffer byteBuffer) {
+        int arrayLength = (short)(byteBuffer.get() & 255);
+        byte[] nextByteArray = new byte[arrayLength];
+        byteBuffer.get(nextByteArray);
+        return nextByteArray;
+    }
+
+    protected int[] getNextIntArray(ByteBuffer byteBuffer) {
+        int arrayLength = (short)(byteBuffer.get() & 255);
+        int[] nextIntArray = new int[arrayLength];
+        for (int i = 0; i < arrayLength; i++) {
+            nextIntArray[i] = byteBuffer.getInt();
+        }
+        return nextIntArray;
+    }
+
+    protected void addByteArrayWithLengthByte(ByteBuffer buffer, byte[] data) {
+        buffer.put((byte) data.length);
+        if (data.length != 0) {
+            buffer.put(data);
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WithingsStructureType.java

@@ -0,0 +1,72 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+public class WithingsStructureType {
+
+    public static final short END_OF_TRANSMISSION = 256;
+    public static final short PROBE_REPLY = 257;
+    public static final short PROBE = 298;
+    public static final short CHALLENGE = 290;
+    public static final short CHALLENGE_RESPONSE = 291;
+    public static final short PROBE_OS_VERSION = 2344;
+    public static final short TIME = 1281;
+    public static final short SCREEN_SETTINGS = 1302;
+    public static final short WORKOUT_SCREEN_SETTINGS = 317;
+    public static final short BATTERY_STATUS = 1284;
+    public static final short USER = 1283;
+    public static final short USER_SECRET = 1299;
+    public static final short USER_UNIT = 281;
+    public static final short ACTIVITY_TARGET = 1297;
+    public static final short LOCALE = 289;
+    public static final short LIVE_HR = 2369;
+    public static final short HR = 2343;
+    public static final short ACTIVITY_HR = 2345;
+    public static final short ALARM = 1298;
+    public static final short ALARM_STATUS = 2329;
+    public static final short ALARM_NAME = 1300;
+    public static final short STEPS = 2390;
+    public static final short IMAGE_META_DATA = 2397;
+    public static final short IMAGE_DATA = 2398;
+    public static final short ANCS_STATUS = 2346;
+    public static final short NOTIFICATION_APP_ID = 2404;
+    public static final short GLYPH_ID = 2396;
+    public static final short MOVE_HAND = 1292;
+
+    public static final short GET_ACTIVITY_SAMPLES = 1286;
+    public static final short ACTIVITY_SAMPLE_TIME = 1537;
+    public static final short ACTIVITY_SAMPLE_DURATION = 1538;
+    public static final short ACTIVITY_SAMPLE_MOVEMENT = 1539;
+    public static final short ACTIVITY_SAMPLE_WALK = 1540;
+    public static final short ACTIVITY_SAMPLE_RUN = 1541;
+    public static final short ACTIVITY_SAMPLE_SWIM = 1549;
+    public static final short ACTIVITY_SAMPLE_SLEEP = 1543;
+    // There are two structure types containing information about calories:
+    public static final short ACTIVITY_SAMPLE_CALORIES = 1544;
+    public static final short ACTIVITY_SAMPLE_CALORIES_2 = 1546;
+    // No idea what this is, however it is in the response to requesting activities:
+    public static final short ACTIVITY_SAMPLE_UNKNOWN = 1547;
+    public static final short WORKOUT_TYPE = 2409;
+    public static final short LIVE_WORKOUT_START = 2418;
+    public static final short LIVE_WORKOUT_END = 2419;
+    public static final short LIVE_WORKOUT_PAUSE_STATE = 2439;
+    public static final short WORKOUT_GPS_STATE = 321;
+    public static final short WORKOUT_SCREEN_LIST = 316;
+    public static final short WORKOUT_SCREEN_DATA = 317;
+
+    private WithingsStructureType() {}
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WorkoutGpsState.java

@@ -0,0 +1,43 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class WorkoutGpsState extends WithingsStructure {
+
+    private final boolean gpsEnabled;
+
+    public WorkoutGpsState(boolean gpsEnabled) {
+        this.gpsEnabled = gpsEnabled;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+        buffer.putShort(gpsEnabled? (short)1 : 0);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.WORKOUT_GPS_STATE;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WorkoutScreen.java

@@ -0,0 +1,67 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class WorkoutScreen extends WithingsStructure {
+
+    public static final byte MODE_PACE = 2;
+    public static final byte MODE_SPEED = 3;
+    public static final byte MODE_ELSE = 1;
+
+    public int id;
+
+    public byte yetunknown1 = 0;
+
+    public String name;
+
+    public byte mode = MODE_PACE;
+
+    public short yetunknown2 = 0;
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void setMode(byte mode) {
+        this.mode = mode;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.WORKOUT_SCREEN_SETTINGS;
+    }
+
+    @Override
+    public short getLength() {
+        return (short) ((name != null ? name.getBytes().length : 0) + 9 + HEADER_SIZE);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer rawDataBuffer) {
+        rawDataBuffer.putInt(id);
+        rawDataBuffer.put(yetunknown1);
+        addStringAsBytesWithLengthByte(rawDataBuffer, name);
+        rawDataBuffer.put(mode);
+        rawDataBuffer.putShort(yetunknown2);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WorkoutScreenData.java

@@ -0,0 +1,52 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class WorkoutScreenData extends WithingsStructure {
+
+    public long id;
+    public short version;
+    public String name;
+    public short faceMode;
+    public int flag;
+
+    @Override
+    public short getLength() {
+        return (short) ((name != null ? name.getBytes().length : 0) + 13);
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        this.id = rawDataBuffer.getInt() & 4294967295L;
+        this.version = (short) (rawDataBuffer.get() & 255);
+        this.name = getNextString(rawDataBuffer);
+        this.faceMode = (short) (rawDataBuffer.get() & 255);
+        this.flag = rawDataBuffer.getShort() & 65535;
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.WORKOUT_SCREEN_DATA;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WorkoutScreenList.java

@@ -0,0 +1,48 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class WorkoutScreenList extends WithingsStructure {
+
+    private int[] workoutIds;
+
+    public int[] getWorkoutIds() {
+        return workoutIds;
+    }
+
+    @Override
+    public short getLength() {
+        return 37;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    protected void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        workoutIds = getNextIntArray(rawDataBuffer);
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.WORKOUT_SCREEN_LIST;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/datastructures/WorkoutType.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures;
+
+import java.nio.ByteBuffer;
+
+public class WorkoutType extends WithingsStructure {
+
+    public static short RUNNING = 0;
+
+    private short activityType;
+
+    public short getActivityType() {
+        return activityType;
+    }
+
+    @Override
+    public short getLength() {
+        return 6;
+    }
+
+    @Override
+    protected void fillinTypeSpecificData(ByteBuffer buffer) {
+
+    }
+
+    @Override
+    public void fillFromRawDataAsBuffer(ByteBuffer rawDataBuffer) {
+        activityType = rawDataBuffer.getShort();
+    }
+
+    @Override
+    public short getType() {
+        return WithingsStructureType.WORKOUT_TYPE;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/AbstractMessage.java

@@ -0,0 +1,98 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public abstract class AbstractMessage implements Message {
+
+    /**
+     * The header consist of the first byte 0x01 (probably the message format identifier),
+     * two bytes for the message type and 2 bytes for the actual datalength.
+     */
+    private static final int HEADER_SIZE = 5;
+    protected final static short EOM_SIZE = 4;
+
+    private List<WithingsStructure> dataStructures = new ArrayList<WithingsStructure>();
+
+    public List<WithingsStructure> getDataStructures() {
+        return Collections.unmodifiableList(dataStructures);
+    }
+
+    @Override
+    public void addDataStructure(WithingsStructure data) {
+        dataStructures.add(data);
+    }
+
+    @Override
+    public byte[] getRawData() {
+        short structureLength = 0;
+        boolean setEndOfMessage = false;
+        for (WithingsStructure structure : dataStructures) {
+            if (structure.withEndOfMessage()) {
+                setEndOfMessage = true;
+            }
+            structureLength += (short)(structure.getLength());
+        }
+
+        if (setEndOfMessage) {
+            structureLength += EOM_SIZE;
+        }
+
+        ByteBuffer rawDataBuffer = ByteBuffer.allocate(HEADER_SIZE + structureLength);
+        rawDataBuffer.put((byte)0x01); // <= This seems to be always 0x01 for all commands
+        rawDataBuffer.putShort(getType());
+        rawDataBuffer.putShort(structureLength);
+
+        for (WithingsStructure structure : dataStructures) {
+            rawDataBuffer.put(structure.getRawData());
+        }
+
+        if (setEndOfMessage) {
+            addEndOfMessageBytes(rawDataBuffer);
+        }
+
+        return rawDataBuffer.array();
+    }
+
+    @Override
+    public <T extends WithingsStructure> T getStructureByType(Class<T> type) {
+        for (WithingsStructure structure : this.getDataStructures()) {
+            if (type.isInstance(structure)) {
+                return (T)structure;
+            }
+        }
+
+        return null;
+    }
+
+    private void addEndOfMessageBytes(ByteBuffer buffer) {
+        buffer.putShort((short)256);
+        buffer.putShort((short)0);
+    }
+
+    public String toString() {
+        return GB.hexdump(this.getRawData()).toLowerCase(Locale.ROOT);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/ExpectedResponse.java

@@ -0,0 +1,23 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+public enum ExpectedResponse {
+    NONE,
+    SIMPLE,
+    EOT
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/GlyphRequestHandler.java

@@ -0,0 +1,92 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.widget.Toast;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.IconHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.GlyphId;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageMetaData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming.IncomingMessageHandler;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class GlyphRequestHandler implements IncomingMessageHandler {
+    private static final Logger logger = LoggerFactory.getLogger(GlyphRequestHandler.class);
+    private final WithingsSteelHRDeviceSupport support;
+
+    public GlyphRequestHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    @Override
+    public void handleMessage(Message message) {
+        try {
+            GlyphId glyphId = message.getStructureByType(GlyphId.class);
+            ImageMetaData imageMetaData = message.getStructureByType(ImageMetaData.class);
+            Message reply = new WithingsMessage(WithingsMessageType.GET_UNICODE_GLYPH);
+            reply.addDataStructure(glyphId);
+            reply.addDataStructure(imageMetaData);
+            ImageData imageData = new ImageData();
+            imageData.setImageData(createUnicodeImage(glyphId.getUnicode(), imageMetaData));
+            reply.addDataStructure(imageData);
+            logger.info("Sending reply to glyph request: " + reply);
+            support.sendToDevice(reply);
+        } catch (Exception e) {
+            logger.error("Failed to respond to glyph request.", e);
+            GB.toast("Failed to respond to glyph request:" + e.getMessage(), Toast.LENGTH_LONG, GB.WARN);
+        }
+    }
+
+    private byte[] createUnicodeImage(long unicode, ImageMetaData metaData) {
+        String str = new String(Character.toChars((int)unicode));
+        Paint paint = new Paint();
+        paint.setTypeface(null);
+        Rect rect = new Rect();
+        paint.setTextSize(calculateTextsize(paint, metaData.getHeight()));
+        paint.setAntiAlias(true);
+        paint.getTextBounds(str, 0, str.length(), rect);
+        paint.setColor(-1);
+        Paint.FontMetricsInt fontMetricsInt = paint.getFontMetricsInt();
+        int width = rect.width();
+        if (width <= 0) {
+            return new byte[0];
+        }
+        Bitmap createBitmap = Bitmap.createBitmap(width, metaData.getHeight(), Bitmap.Config.ARGB_8888);
+        new Canvas(createBitmap).drawText(str, -rect.left, -fontMetricsInt.top, paint);
+        return IconHelper.toByteArray(createBitmap);
+    }
+
+    private int calculateTextsize(Paint paint, int height) {
+        Paint.FontMetricsInt fontMetricsInt;
+        int textsize = 0;
+        do {
+            textsize++;
+            paint.setTextSize(textsize);
+            fontMetricsInt = paint.getFontMetricsInt();
+        } while (fontMetricsInt.bottom - fontMetricsInt.top < height);
+        return textsize - 1;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/Message.java

@@ -0,0 +1,36 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+
+/**
+ * This interface is the common denominator for all messages passed to and from the Steel HR.
+ *
+ */
+public interface Message {
+    List<WithingsStructure> getDataStructures();
+    void addDataStructure(WithingsStructure data);
+    short getType();
+    byte[] getRawData();
+    boolean needsResponse();
+    boolean needsEOT();
+    boolean isIncomingMessage();
+    <T extends WithingsStructure> T getStructureByType(Class<T> type);
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/MessageBuilder.java

@@ -0,0 +1,89 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
+
+public class MessageBuilder {
+
+    private static final Logger logger = LoggerFactory.getLogger(MessageBuilder.class);
+    private WithingsSteelHRDeviceSupport support;
+    private MessageFactory messageFactory;
+    private ByteArrayOutputStream pendingMessage;
+    private Message message;
+
+    public MessageBuilder(WithingsSteelHRDeviceSupport support, MessageFactory messageFactory) {
+        this.support = support;
+        this.messageFactory = messageFactory;
+    }
+
+    public synchronized boolean buildMessage(byte[] rawData) {
+        if (pendingMessage == null && rawData[0] == 0x01) {
+            pendingMessage = new ByteArrayOutputStream();
+        } else if (pendingMessage == null) {
+            return false;
+        }
+
+        try {
+            pendingMessage.write(rawData);
+        } catch(IOException e) {
+            logger.error("Could not write data to stream: " + StringUtils.bytesToHex(rawData));
+            return false;
+        }
+
+        if (!isMessageComplete(pendingMessage.toByteArray())) {
+            return false;
+        } else {
+            Message message = messageFactory.createMessageFromRawData(pendingMessage.toByteArray());
+            pendingMessage = null;
+            if (message == null) {
+                logger.info("Cannot handle null message");
+                return false;
+            }
+
+            this.message = message;
+            return true;
+        }
+    }
+
+    public Message getMessage() {
+        return message;
+    }
+
+    private boolean isMessageComplete(byte[] messageData) {
+        if (messageData.length < 5) {
+            return false;
+        }
+
+        short totalDataLength = (short) BLETypeConversions.toInt16(messageData[4], messageData[3]);
+        byte[] rawStructureData = Arrays.copyOfRange(messageData, 5, messageData.length);
+        if (rawStructureData.length == totalDataLength) {
+            return true;
+        }
+
+        return false;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/MessageFactory.java

@@ -0,0 +1,55 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.DataStructureFactory;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+
+
+public class MessageFactory {
+    private static final Logger logger = LoggerFactory.getLogger(MessageFactory.class);
+    private DataStructureFactory dataStructureFactory;
+
+    public MessageFactory(DataStructureFactory dataStructureFactory) {
+        this.dataStructureFactory = new DataStructureFactory();
+    }
+
+    public Message createMessageFromRawData(byte[] rawData) {
+        if (rawData.length < 5 || rawData[0] != 0x01) {
+            return null;
+        }
+
+        short messageTypeFromResponse = (short) (BLETypeConversions.toInt16(rawData[2], rawData[1]) & 16383);
+        short totalDataLength = (short) BLETypeConversions.toInt16(rawData[4], rawData[3]);
+        boolean isIncoming = rawData[1] == 65 || rawData[1] == -127;
+        Message message = new WithingsMessage(messageTypeFromResponse, isIncoming);
+        byte[] rawStructureData = Arrays.copyOfRange(rawData, 5, rawData.length);
+        List<WithingsStructure> structures = dataStructureFactory.createStructuresFromRawData(rawStructureData);
+        for (WithingsStructure structure : structures) {
+            message.addDataStructure(structure);
+        }
+
+        return message;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/SimpleHexToByteMessage.java

@@ -0,0 +1,71 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class SimpleHexToByteMessage implements Message {
+    private String hexString;
+
+    public SimpleHexToByteMessage(String hexString) {
+        this.hexString = hexString;
+    }
+
+    @Override
+    public List<WithingsStructure> getDataStructures() {
+        return null;
+    }
+
+    @Override
+    public void addDataStructure(WithingsStructure data) {
+
+    }
+
+    @Override
+    public short getType() {
+        return 0;
+    }
+
+    @Override
+    public byte[] getRawData() {
+        return GB.hexStringToByteArray(hexString);
+    }
+
+    @Override
+    public boolean needsResponse() {
+        return false;
+    }
+
+    @Override
+    public boolean needsEOT() {
+        return false;
+    }
+
+    @Override
+    public boolean isIncomingMessage() {
+        return false;
+    }
+
+    @Override
+    public <T extends WithingsStructure> T getStructureByType(Class<T> type) {
+        return null;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/WithingsMessage.java

@@ -0,0 +1,64 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+
+public class WithingsMessage extends AbstractMessage {
+    private short type;
+    private ExpectedResponse expectedResponse = ExpectedResponse.SIMPLE;
+    private boolean isIncoming;
+
+    public WithingsMessage(short type) {
+        this.type = type;
+    }
+
+    public WithingsMessage(short type, boolean incoming) {
+        this.type = type;
+        this.isIncoming = incoming;
+    }
+
+    public WithingsMessage(short type, ExpectedResponse expectedResponse) {
+        this.type = type;
+        this.expectedResponse = expectedResponse;
+    }
+
+    public WithingsMessage(short type, WithingsStructure dataStructure) {
+        this.type = type;
+        this.addDataStructure(dataStructure);
+    }
+
+    @Override
+    public boolean needsResponse() {
+        return expectedResponse == ExpectedResponse.SIMPLE;
+    }
+
+    @Override
+    public boolean needsEOT() {
+        return expectedResponse == ExpectedResponse.EOT;
+    }
+
+    @Override
+    public short getType() {
+        return type;
+    }
+
+    @Override
+    public boolean isIncomingMessage() {
+        return isIncoming;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/WithingsMessageType.java

@@ -0,0 +1,68 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message;
+
+/**
+ * Contains all identified commandtypes in the used TLV format of the messages exchanged
+ * between device and app.
+ */
+public final class WithingsMessageType {
+
+    public static final short PROBE = 257;
+    public static final short CHALLENGE = 296;
+    public static final short SET_TIME = 1281;
+    public static final short GET_BATTERY_STATUS = 1284;
+    public static final short SET_SCREEN_LIST = 1292;
+    public static final short INITIAL_CONNECT = 273;
+    public static final short START_HANDS_CALIBRATION = 286;
+    public static final short STOP_HANDS_CALIBRATION = 287;
+    public static final short MOVE_HAND = 284;
+    public static final short SET_ACTIVITY_TARGET = 1290;
+    public static final short SET_USER = 1282;
+    public static final short GET_USER = 1283;
+    public static final short SET_USER_UNIT = 274;
+    public static final short SET_LOCALE = 282;
+    public static final short SETUP_FINISHED = 275;
+    public static final short GET_HR = 2343;
+    public static final short GET_WORKOUT_SCREEN_LIST = 315;
+    public static final short SET_WORKOUT_SCREEN = 316;
+    public static final short START_LIVE_WORKOUT = 317;
+    public static final short STOP_LIVE_WORKOUT = 318;
+    public static final short SYNC = 321;
+    public static final short SYNC_RESPONSE = 16705;
+    public static final short SYNC_OK = 277;
+    public static final short GET_ALARM_SETTINGS = 298;
+    public static final short SET_ALARM = 325;
+    public static final short GET_ALARM = 293;
+    public static final short GET_ALARM_ENABLED = 2330;
+    public static final short SET_ALARM_ENABLED = 2331;
+    public static final short GET_ANCS_STATUS = 2353;
+    public static final short SET_ANCS_STATUS = 2345;
+    public static final short GET_SCREEN_SETTINGS = 1293;
+    // The next two do nearly the same, when I look at the responses, though only the first seems to deliver sleep samples
+    public static final short GET_ACTIVITY_SAMPLES = 2424;
+    public static final short GET_MOVEMENT_SAMPLES = 1286;
+
+    public static final short GET_SPORT_MODE = 2371;
+    public static final short GET_WORKOUT_GPS_STATUS = 323;
+    public static final short GET_HEARTRATE_SAMPLES = 2344;
+    public static final short LIVE_WORKOUT_DATA = 320;
+    public static final short GET_NOTIFICATION = 2404;
+    public static final short GET_UNICODE_GLYPH = 2403;
+
+    private WithingsMessageType() {}
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/IncomingMessageHandler.java

@@ -0,0 +1,23 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public interface IncomingMessageHandler {
+    public void handleMessage(Message message);
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/IncomingMessageHandlerFactory.java

@@ -0,0 +1,86 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.GlyphRequestHandler;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+
+public class IncomingMessageHandlerFactory {
+
+    private static final Logger logger = LoggerFactory.getLogger(IncomingMessageHandlerFactory.class);
+    private static IncomingMessageHandlerFactory instance;
+    private final WithingsSteelHRDeviceSupport support;
+    private Map<Short, IncomingMessageHandler> handlers = new HashMap<>();
+
+    private IncomingMessageHandlerFactory(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    public static IncomingMessageHandlerFactory getInstance(WithingsSteelHRDeviceSupport support) {
+        if (instance == null) {
+            instance = new IncomingMessageHandlerFactory(support);
+        }
+
+        return instance;
+    }
+
+    public IncomingMessageHandler getHandler(Message message) {
+        IncomingMessageHandler handler = handlers.get(message.getType());
+        switch (message.getType()) {
+            case WithingsMessageType.START_LIVE_WORKOUT:
+            case WithingsMessageType.STOP_LIVE_WORKOUT:
+            case WithingsMessageType.GET_WORKOUT_GPS_STATUS:
+                if (handler == null) {
+                    handlers.put(message.getType(), new LiveWorkoutHandler(support));
+                }
+                break;
+            case WithingsMessageType.LIVE_WORKOUT_DATA:
+                if (handler == null) {
+                    handlers.put(message.getType(), new LiveHeartrateHandler(support));
+                }
+                break;
+            case WithingsMessageType.GET_NOTIFICATION:
+                if (handler == null) {
+                    handlers.put(message.getType(), new NotificationRequestHandler(support));
+                }
+                break;
+            case WithingsMessageType.GET_UNICODE_GLYPH:
+                if (handler == null) {
+                    handlers.put(message.getType(), new GlyphRequestHandler(support));
+                }
+                break;
+            case WithingsMessageType.SYNC:
+                if (handler == null) {
+                    handlers.put(message.getType(), new SyncRequestHandler(support));
+                }
+                break;
+            default:
+                logger.warn("Unhandled incoming message type: " + message.getType());
+        }
+
+        return handlers.get(message.getType());
+    }
+
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/LiveHeartrateHandler.java

@@ -0,0 +1,88 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import android.content.Intent;
+
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.GregorianCalendar;
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.withingssteelhr.WithingsSteelHRSampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.entities.WithingsSteelHRActivitySample;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceService;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.SleepActivitySampleHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.LiveHeartRate;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+
+public class LiveHeartrateHandler implements IncomingMessageHandler {
+    private static final Logger logger = LoggerFactory.getLogger(LiveHeartrateHandler.class);
+    private final WithingsSteelHRDeviceSupport support;
+
+    public LiveHeartrateHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+
+    @Override
+    public void handleMessage(Message message) {
+        List<WithingsStructure> data = message.getDataStructures();
+        if (data == null || data.isEmpty()) {
+            return;
+        }
+
+        WithingsStructure structure = data.get(0);
+        int heartRate = 0;
+        if (structure instanceof LiveHeartRate) {
+            heartRate = ((LiveHeartRate)structure).getHeartrate();
+        }
+
+        if (heartRate > 0) {
+            saveHeartRateData(heartRate);
+        }
+    
+    }
+    
+    private void saveHeartRateData(int heartRate) {
+        WithingsSteelHRActivitySample sample = new WithingsSteelHRActivitySample();
+        sample.setTimestamp((int) (GregorianCalendar.getInstance().getTimeInMillis() / 1000L));
+        sample.setHeartRate(heartRate);
+        try (DBHandler dbHandler = GBApplication.acquireDB()) {
+            Long userId = DBHelper.getUser(dbHandler.getDaoSession()).getId();
+            Long deviceId = DBHelper.getDevice(support.getDevice(), dbHandler.getDaoSession()).getId();
+            WithingsSteelHRSampleProvider provider = new WithingsSteelHRSampleProvider(support.getDevice(), dbHandler.getDaoSession());
+            sample.setDeviceId(deviceId);
+            sample.setUserId(userId);
+            sample = SleepActivitySampleHelper.mergeIfNecessary(provider, sample);
+            provider.addGBActivitySample(sample);
+        } catch (Exception ex) {
+            logger.warn("Error saving current heart rate: " + ex.getLocalizedMessage());
+        }
+        Intent intent = new Intent(DeviceService.ACTION_REALTIME_SAMPLES)
+                .putExtra(DeviceService.EXTRA_REALTIME_SAMPLE, sample);
+        LocalBroadcastManager.getInstance(support.getContext()).sendBroadcast(intent);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/LiveWorkoutHandler.java

@@ -0,0 +1,147 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import android.location.LocationManager;
+import android.widget.Toast;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.GBApplication;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
+import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
+import nodomain.freeyourgadget.gadgetbridge.entities.BaseActivitySummary;
+import nodomain.freeyourgadget.gadgetbridge.entities.DaoSession;
+import nodomain.freeyourgadget.gadgetbridge.entities.Device;
+import nodomain.freeyourgadget.gadgetbridge.entities.User;
+import nodomain.freeyourgadget.gadgetbridge.externalevents.opentracks.OpenTracksController;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.activity.WithingsActivityType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.LiveWorkoutEnd;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.LiveWorkoutPauseState;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.LiveWorkoutStart;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructure;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WithingsStructureType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WorkoutGpsState;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.WorkoutType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class LiveWorkoutHandler implements IncomingMessageHandler {
+    private static final Logger logger = LoggerFactory.getLogger(LiveWorkoutHandler.class);
+    private final WithingsSteelHRDeviceSupport support;
+    private BaseActivitySummary baseActivitySummary;
+
+    public LiveWorkoutHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    public void handleMessage(Message message) {
+        List<WithingsStructure> data = message.getDataStructures();
+        if (data != null) {
+            handleLiveData(data);
+        }
+    }
+
+    private void handleLiveData(List<WithingsStructure> dataList) {
+        for (WithingsStructure data : dataList) {
+            switch (data.getType()) {
+                case WithingsStructureType.LIVE_WORKOUT_START:
+                    handleStart((LiveWorkoutStart) data);
+                    break;
+                case WithingsStructureType.LIVE_WORKOUT_END:
+                    handleEnd((LiveWorkoutEnd) data);
+                    break;
+                case WithingsStructureType.LIVE_WORKOUT_PAUSE_STATE:
+                    handlePause((LiveWorkoutPauseState) data);
+                    break;
+                case WithingsStructureType.WORKOUT_TYPE:
+                    handleType((WorkoutType) data);
+                    break;
+                default:
+                    logger.info("Received yet unhandled live workout data of type '" + data.getType() + "' with data '" + GB.hexdump(data.getRawData()) + "'.");
+            }
+        }
+    }
+
+    private void handleStart(LiveWorkoutStart workoutStart) {
+        sendGpsState();
+        if (baseActivitySummary == null) {
+            baseActivitySummary = new BaseActivitySummary();
+        }
+
+        baseActivitySummary.setStartTime(workoutStart.getStarttime());
+    }
+
+    private void handlePause(LiveWorkoutPauseState workoutPause) {
+        // Not sure what to do with these events at the moment so we just log them.
+        if (workoutPause.getStarttime() == null) {
+            if (workoutPause.getLengthInSeconds() > 0) {
+                logger.info("Got workout pause end with duration: " + workoutPause.getLengthInSeconds());
+            } else {
+                logger.info("Currently no pause happened");
+            }
+        } else {
+            logger.info("Got workout pause started at: " + workoutPause.getStarttime());
+        }
+    }
+
+    private void handleEnd(LiveWorkoutEnd workoutEnd) {
+        OpenTracksController.stopRecording(support.getContext());
+        baseActivitySummary.setEndTime(workoutEnd.getEndtime());
+        saveBaseActivitySummary();
+        baseActivitySummary = null;
+    }
+
+    private void handleType(WorkoutType workoutType) {
+        WithingsActivityType withingsWorkoutType = WithingsActivityType.fromCode(workoutType.getActivityType());
+        OpenTracksController.startRecording(support.getContext(), withingsWorkoutType.toActivityKind());
+        if (baseActivitySummary == null) {
+            baseActivitySummary = new BaseActivitySummary();
+        }
+
+        baseActivitySummary.setActivityKind(withingsWorkoutType.toActivityKind());
+    }
+
+    private void sendGpsState() {
+        Message message = new WithingsMessage((short)(WithingsMessageType.START_LIVE_WORKOUT | 16384), new WorkoutGpsState(isGpsEnabled()));
+        support.sendToDevice(message);
+    }
+
+    private boolean isGpsEnabled() {
+        final LocationManager manager = (LocationManager) support.getContext().getSystemService(support.getContext().LOCATION_SERVICE );
+        return manager.isProviderEnabled(LocationManager.GPS_PROVIDER );
+    }
+
+    private void saveBaseActivitySummary() {
+        try (DBHandler dbHandler = GBApplication.acquireDB()) {
+            DaoSession session = dbHandler.getDaoSession();
+            Device device = DBHelper.getDevice(support.getDevice(), session);
+            User user = DBHelper.getUser(session);
+            baseActivitySummary.setDevice(device);
+            baseActivitySummary.setUser(user);
+            session.getBaseActivitySummaryDao().insertOrReplace(baseActivitySummary);
+        } catch (Exception ex) {
+            GB.toast(support.getContext(), "Error saving activity summary", Toast.LENGTH_LONG, GB.ERROR, ex);
+        }
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/NotificationRequestHandler.java

@@ -0,0 +1,101 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.graphics.drawable.Drawable;
+import android.widget.Toast;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import nodomain.freeyourgadget.gadgetbridge.model.NotificationSpec;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.IconHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.ImageMetaData;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.datastructures.SourceAppId;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification.NotificationProvider;
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+
+public class NotificationRequestHandler implements IncomingMessageHandler {
+    private static final Logger logger = LoggerFactory.getLogger(NotificationRequestHandler.class);
+
+    private final WithingsSteelHRDeviceSupport support;
+    private Map<String, byte[]> appIconCache = new HashMap<>();
+
+    public NotificationRequestHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    @Override
+    public void handleMessage(Message message) {
+        try {
+            SourceAppId appId = message.getStructureByType(SourceAppId.class);
+            ImageMetaData imageMetaData = message.getStructureByType(ImageMetaData.class);
+            Message reply = new WithingsMessage(WithingsMessageType.GET_NOTIFICATION);
+            reply.addDataStructure(appId);
+            reply.addDataStructure(imageMetaData);
+            ImageData imageData = new ImageData();
+            imageData.setImageData(getImageData(appId.getAppId()));
+            reply.addDataStructure(imageData);
+            logger.info("Sending reply to notification request: " + reply);
+            support.sendToDevice(reply);
+        } catch (Exception e) {
+            logger.error("Failed to respond to notification request.", e);
+            GB.toast("Failed to respond to notification request:" + e.getMessage(), Toast.LENGTH_LONG, GB.WARN);
+        }
+    }
+
+    private byte[] getImageData(String sourceAppId) {
+        byte[] imageData = appIconCache.get(sourceAppId);
+        if (imageData == null) {
+            NotificationSpec notificationSpec = NotificationProvider.getInstance(support).getNotificationSpecForSourceAppId(sourceAppId);
+            if (notificationSpec != null) {
+                int iconId = notificationSpec.iconId;
+                try {
+                    Drawable icon = null;
+                    if (notificationSpec.iconId != 0) {
+                        Context sourcePackageContext = support.getContext().createPackageContext(sourceAppId, 0);
+                        icon = sourcePackageContext.getResources().getDrawable(notificationSpec.iconId);
+                    }
+                    if (icon == null) {
+                        PackageManager pm = support.getContext().getPackageManager();
+                        icon = pm.getApplicationIcon(sourceAppId);
+                    }
+
+                    imageData = IconHelper.getIconBytesFromDrawable(icon);
+                    appIconCache.put(sourceAppId, imageData);
+                } catch (PackageManager.NameNotFoundException e) {
+                    logger.error("Error while updating notification icons", e);
+                    imageData = new byte[0];
+                }
+            } else {
+                imageData = new byte[0];
+            }
+        }
+
+        return imageData;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/message/incoming/SyncRequestHandler.java

@@ -0,0 +1,38 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.incoming;
+
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.WithingsSteelHRDeviceSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.ExpectedResponse;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.Message;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessage;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.message.WithingsMessageType;
+
+public class SyncRequestHandler implements IncomingMessageHandler {
+
+    private final WithingsSteelHRDeviceSupport support;
+
+    public SyncRequestHandler(WithingsSteelHRDeviceSupport support) {
+        this.support = support;
+    }
+
+    @Override
+    public void handleMessage(Message message) {
+        support.sendToDevice(new WithingsMessage(WithingsMessageType.SYNC_RESPONSE));
+        support.doSync();
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/notification/AncsConstants.java

@@ -0,0 +1,45 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification;
+
+public final class AncsConstants {
+
+    public static final byte EVENT_ID_NOTIFICATION_ADDED = 0;
+    public static final byte EVENT_ID_NOTIFICATION_MODIFIED = 1;
+    public static final byte EVENT_ID_NOTIFICATION_REMOVED = 2;
+
+    public static final byte EVENT_FLAGS_SILENT = (1 << 0);
+    public static final byte EVENT_FLAGS_IMPORTANT = (1 << 1);
+    public static final byte EVENT_FLAGS_PREEXISTING = (1 << 2);
+    public static final byte EVENT_FLAGS_POSITIVE_ACTION = (1 << 3);
+    public static final byte EVENT_FLAGS_NEGATIVE_ACTION = (1 << 4);
+
+    public static final byte CATEGORY_ID_OTHER = 0;
+    public static final byte CATEGORY_ID_INCOMING_CALL = 1;
+    public static final byte CATEGORY_ID_MISSED_CALL = 2;
+    public static final byte CATEGORY_ID_VOICEMAIL = 3;
+    public static final byte CATEGORY_ID_SOCIAL = 4;
+    public static final byte CATEGORY_ID_SCHEDULE = 5;
+    public static final byte CATEGORY_ID_EMAIL = 6;
+    public static final byte CATEGORY_ID_NEWS = 7;
+    public static final byte CATEGORY_ID_HEALTHANDFITNESS = 8;
+    public static final byte CATEGORY_ID_BUSINESSANDFINANCE = 9;
+    public static final byte CATEGORY_ID_LOCATION = 10;
+    public static final byte CATEGORY_ID_ENTERTAINMENT = 11;
+
+    private AncsConstants(){}
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/notification/GetNotificationAttributes.java

@@ -0,0 +1,76 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+
+public class GetNotificationAttributes {
+    private byte commandID;
+    private int notificationUID;
+    private List<RequestedNotificationAttribute> attributes = new ArrayList<>();
+
+    public byte getCommandID() {
+        return commandID;
+    }
+
+    public void setCommandID(byte commandID) {
+        this.commandID = commandID;
+    }
+
+    public int getNotificationUID() {
+        return notificationUID;
+    }
+
+    public void setNotificationUID(int notificationUID) {
+        this.notificationUID = notificationUID;
+    }
+
+    public List<RequestedNotificationAttribute> getAttributes() {
+        return Collections.unmodifiableList(attributes);
+    }
+
+    public void addAttribute(RequestedNotificationAttribute attribute) {
+        attributes.add(attribute);
+    }
+
+    public void deserialize(byte[] rawData) {
+        ByteBuffer buffer = ByteBuffer.wrap(rawData);
+        commandID = buffer.get();
+        notificationUID = buffer.getInt();
+        while (buffer.hasRemaining()) {
+            RequestedNotificationAttribute requestedNotificationAttribute = new RequestedNotificationAttribute();
+            int length = 1;
+            if (buffer.remaining() >= 3) {
+                length = 3;
+            }
+
+            byte[] rawAttributeData = new byte[length];
+            buffer.get(rawAttributeData);
+            requestedNotificationAttribute.deserialize(rawAttributeData);
+            attributes.add(requestedNotificationAttribute);
+        }
+    }
+
+    public byte[] serialize() {
+        return new byte[0];
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/notification/GetNotificationAttributesResponse.java

@@ -0,0 +1,57 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.ArrayList;
+import java.util.List;
+
+public class GetNotificationAttributesResponse {
+    private byte commandID = 0;
+    private int notificationUID;
+    private List<NotificationAttribute> attributes = new ArrayList<>();
+
+    public GetNotificationAttributesResponse(int notificationUID) {
+        this.notificationUID = notificationUID;
+    }
+
+    public void addAttribute(NotificationAttribute attribute) {
+        attributes.add(attribute);
+    }
+
+    public byte[] serialize() {
+        ByteBuffer buffer = ByteBuffer.allocate(getLength());
+        buffer.put(commandID);
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        buffer.putInt(notificationUID);
+        buffer.order(ByteOrder.BIG_ENDIAN);
+        for (NotificationAttribute attribute : attributes) {
+            buffer.put(attribute.serialize());
+        }
+        return buffer.array();
+    }
+
+    private int getLength() {
+        int length = 5;
+        for (NotificationAttribute attribute : attributes) {
+            length += attribute.getAttributeLength() + 3;
+        }
+
+        return length;
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/withingssteelhr/communication/notification/NotificationAttribute.java

@@ -0,0 +1,88 @@
+/*  Copyright (C) 2021 Frank Ertl
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.withingssteelhr.communication.notification;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.charset.StandardCharsets;
+
+import nodomain.freeyourgadget.gadgetbridge.util.GB;
+import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
+
+public class NotificationAttribute {
+    private byte attributeID;
+    private short attributeLength;
+    private short attributeMaxLength;
+    private String value;
+
+    public void setAttributeMaxLength(short attributeMaxLength) {
+        this.attributeMaxLength = attributeMaxLength;
+    }
+
+    public byte getAttributeID() {
+        return attributeID;
+    }
+
+    public void setAttributeID(byte attributeID) {
+        this.attributeID = attributeID;
+    }
+
+    public short getAttributeLength() {
+        short length = (short)(value != null? value.getBytes(StandardCharsets.UTF_8).length : 0);
+        if (attributeMaxLength > 0 && length >  attributeMaxLength) {
+            length = attributeMaxLength;
+        }
+
+        return length;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    public byte[] serialize() {
+        attributeLength = getAttributeLength();
+        int length = attributeLength + 3;
+        ByteBuffer buffer = ByteBuffer.allocate(length);
+        buffer.put(attributeID);
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        buffer.putShort(attributeLength);
+        if (value != null) {
+            buffer.order(ByteOrder.BIG_ENDIAN);
+            buffer.put(value.getBytes(StandardCharsets.UTF_8), 0, attributeLength);
+        }
+
+        return buffer.array();
+    }
+
+    public void deserialize(byte[] rawData) {
+        ByteBuffer buffer = ByteBuffer.wrap(rawData);
+        attributeID = buffer.get();
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        attributeLength = buffer.getShort();
+        buffer.order(ByteOrder.BIG_ENDIAN);
+        if (attributeLength > 0) {
+            byte[] rawValue = new byte[attributeLength];
+            buffer.get(rawValue);
+            value = new String(rawValue, StandardCharsets.UTF_8);
+        }
+    }
+}