Even more documentation/specification

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

@@ -2,6 +2,22 @@ package nodomain.freeyourgadget.gadgetbridge.model;
 
 import nodomain.freeyourgadget.gadgetbridge.devices.SampleProvider;
 
+/**
+ * The all-in-one interface for a sample measured by a device with
+ * one or more sensors.
+ *
+ * Each sample is the result of one or more measurements. The values are set for
+ * a specific point in time (see @{link #getTimestamp()}).
+ *
+ * If the sample relates to a user activity (e.g. sleeping, walking, running, ...)
+ * then the activity is provided through @{link #getKind()}.
+ *
+ * Methods will return @{link #NOT_MEASURED} in case no value is available for this
+ * sample.
+ *
+ * The frequency of samples, i.e. the how many samples are recorded per minute, is not specified
+ * and may vary.
+ */
 public interface ActivitySample extends TimeStamped {
 
     int NOT_MEASURED = -1;

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

@@ -2,7 +2,7 @@ package nodomain.freeyourgadget.gadgetbridge.model;
 
 public interface TimeStamped {
     /**
-     * Timestamp of the sample, resolution is seconds!
+     * Unix timestamp of the sample, i.e. the number of seconds since 1970-01-01 00:00:00 UTC.
      */
     int getTimestamp();
 }