Implement elevation gain via barometer.

src/main/java/de/dennisguse/opentracks/content/data/TrackPoint.java

@@ -32,6 +32,7 @@ public class TrackPoint {
     private Float heartRate_bpm = null;
     private Float cyclingCadence_rpm = null;
     private Float power = null;
+    private float elevationGain = Float.NaN;
 
     public TrackPoint() {
         this.location = new Location("");
@@ -92,6 +93,18 @@ public class TrackPoint {
         return location;
     }
 
+    public boolean hasElevationGain() {
+        return !Float.isNaN(elevationGain);
+    }
+
+    public float getElevationGain() {
+        return elevationGain;
+    }
+
+    public void setElevationGain(float elevationGain) {
+        this.elevationGain = elevationGain;
+    }
+
     public double getLatitude() {
         return location.getLatitude();
     }

src/main/java/de/dennisguse/opentracks/fragments/StatisticsRecordedFragment.java

@@ -87,6 +87,10 @@ public class StatisticsRecordedFragment extends Fragment {
     private TextView speedMovingValue;
     private TextView speedMovingUnit;
 
+    private TextView elevationCurrentGroup;
+    private TextView elevationTotalGainValue;
+    private TextView elevationTotalGainUnit;
+
     public static StatisticsRecordedFragment newInstance(Track.Id trackId) {
         Bundle bundle = new Bundle();
         bundle.putParcelable(TRACK_ID_KEY, trackId);
@@ -130,6 +134,11 @@ public class StatisticsRecordedFragment extends Fragment {
         speedMovingLabel = view.findViewById(R.id.stats_moving_speed_label);
         speedMovingValue = view.findViewById(R.id.stats_moving_speed_value);
         speedMovingUnit = view.findViewById(R.id.stats_moving_speed_unit);
+
+        elevationCurrentGroup = view.findViewById(R.id.stats_elevation_current_group);
+
+        elevationTotalGainValue = view.findViewById(R.id.stats_elevation_gain_value);
+        elevationTotalGainUnit = view.findViewById(R.id.stats_elevation_gain_unit);
     }
 
     @Override
@@ -187,6 +196,9 @@ public class StatisticsRecordedFragment extends Fragment {
         speedMovingLabel = null;
         speedMovingValue = null;
         speedMovingUnit = null;
+
+        elevationTotalGainValue = null;
+        elevationTotalGainUnit = null;
     }
 
     public void loadStatistics() {
@@ -264,5 +276,14 @@ public class StatisticsRecordedFragment extends Fragment {
             speedMovingValue.setText(parts.first);
             speedMovingUnit.setText(parts.second);
         }
+
+        // Set elevation gain
+        {
+            double elevationGain_m = trackStatistics != null ? trackStatistics.getTotalElevationGain() : 0f;
+
+            Pair<String, String> parts = StringUtils.formatElevation(getContext(), elevationGain_m, metricUnits);
+            elevationTotalGainValue.setText(parts.first);
+            elevationTotalGainUnit.setText(parts.second);
+        }
     }
 }

src/main/java/de/dennisguse/opentracks/fragments/StatisticsRecordingFragment.java

@@ -132,12 +132,14 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
     private TextView speedMovingLabel;
     private TextView speedMovingValue;
     private TextView speedMovingUnit;
-    private Group elevationGroup;
     private TextView speedLabel;
     private TextView speedValue;
     private TextView speedUnit;
-    private TextView elevationValue;
-    private TextView elevationUnit;
+    private Group elevationCurrentGroup;
+    private TextView elevationCurrentValue;
+    private TextView elevationCurrentUnit;
+    private TextView elevationTotalGainValue;
+    private TextView elevationTotalGainUnit;
     private Group coordinateGroup;
     private TextView latitudeValue;
     private TextView longitudeValue;
@@ -178,14 +180,16 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         speedMovingValue = view.findViewById(R.id.stats_moving_speed_value);
         speedMovingUnit = view.findViewById(R.id.stats_moving_speed_unit);
 
-        elevationGroup = view.findViewById(R.id.stats_elevation_current_group);
-
         speedLabel = view.findViewById(R.id.stats_speed_label);
         speedValue = view.findViewById(R.id.stats_speed_value);
         speedUnit = view.findViewById(R.id.stats_speed_unit);
 
-        elevationValue = view.findViewById(R.id.stats_elevation_current_value);
-        elevationUnit = view.findViewById(R.id.stats_elevation_current_unit);
+        elevationCurrentGroup = view.findViewById(R.id.stats_elevation_current_group);
+        elevationCurrentValue = view.findViewById(R.id.stats_elevation_current_value);
+        elevationCurrentUnit = view.findViewById(R.id.stats_elevation_current_unit);
+
+        elevationTotalGainValue = view.findViewById(R.id.stats_elevation_gain_value);
+        elevationTotalGainUnit = view.findViewById(R.id.stats_elevation_gain_unit);
 
         coordinateGroup = view.findViewById(R.id.stats_coordinate_group);
 
@@ -276,14 +280,16 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         speedMovingValue = null;
         speedMovingUnit = null;
 
-        elevationGroup = null;
-
         speedLabel = null;
         speedValue = null;
         speedUnit = null;
 
-        elevationValue = null;
-        elevationUnit = null;
+        elevationCurrentGroup = null;
+        elevationCurrentValue = null;
+        elevationCurrentUnit = null;
+
+        elevationTotalGainValue = null;
+        elevationTotalGainUnit = null;
 
         coordinateGroup = null;
 
@@ -406,20 +412,25 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
 
     /**
      * Tries to fetch most recent {@link SensorDataSet} from {@link de.dennisguse.opentracks.services.TrackRecordingService}.
+     * Also sets elevation gain.
      */
     private void updateSensorDataUI() {
         TrackRecordingServiceInterface trackRecordingService = trackRecordingServiceConnection.getServiceIfBound();
 
         SensorDataSet sensorDataSet = null;
+        Float elevationGain_m = null;
         if (trackRecordingService == null) {
             Log.d(TAG, "Cannot get the track recording service.");
         } else {
             sensorDataSet = trackRecordingService.getSensorData();
+            elevationGain_m = trackRecordingService.getElevationGain_m();
         }
 
         setHeartRateSensorData(sensorDataSet);
         setCadenceSensorData(sensorDataSet);
         setSpeedSensorData(sensorDataSet, isSelectedTrackRecording());
+
+        setElevationGainFromSensor(elevationGain_m);
     }
 
     private void setHeartRateSensorData(SensorDataSet sensorDataSet) {
@@ -468,6 +479,33 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         cadenceValueView.setText(sensorValue);
     }
 
+    // Set elevation gain
+    public void setTotalElevationGain(Float elevationGain_m) {
+        boolean metricUnits = PreferencesUtils.isMetricUnits(getContext());
+
+        if (elevationGain_m == null) {
+            elevationGain_m = 0f;
+        }
+        if (lastTrackStatistics != null) {
+            elevationGain_m += (float) lastTrackStatistics.getTotalElevationGain();
+        }
+
+        Pair<String, String> parts = StringUtils.formatElevation(getContext(), elevationGain_m, metricUnits);
+        elevationTotalGainValue.setText(parts.first);
+        elevationTotalGainUnit.setText(parts.second);
+    }
+
+    public void setElevationGainFromSensor(Float elevationGain_m) {
+        float totalElevationGain = 0;
+        if (elevationGain_m != null) {
+            totalElevationGain = elevationGain_m;
+        }
+        if (lastTrackStatistics != null) {
+            totalElevationGain += (float) lastTrackStatistics.getTotalElevationGain();
+        }
+        setTotalElevationGain(totalElevationGain);
+    }
+
     /**
      * If cadence and hear rate groups are invisible then sensor horizontal line hast to be invisible too.
      */
@@ -475,7 +513,6 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         if (cadenceGroup.getVisibility() != View.VISIBLE && heartRateGroup.getVisibility() != View.VISIBLE) {
             sensorHorizontalLine.setVisibility(View.GONE);
         }
-
     }
 
     private void setSpeedSensorData(SensorDataSet sensorDataSet, boolean isRecording) {
@@ -555,10 +592,11 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
             speedMovingUnit.setText(parts.second);
         }
 
-        // Make elevation visible?
+        // Set elevation (gain)
         {
+            // Make elevation visible?
             boolean showElevation = PreferencesUtils.isShowStatsElevation(getContext());
-            elevationGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
+            elevationCurrentGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
         }
     }
 
@@ -594,14 +632,14 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
 
         // Set elevation
         boolean showElevation = PreferencesUtils.isShowStatsElevation(getContext());
-        elevationGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
+        elevationCurrentGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
 
         if (showElevation) {
+            // Current elevation
             double altitude = lastTrackPoint != null && lastTrackPoint.hasAltitude() ? lastTrackPoint.getAltitude() : Double.NaN;
             Pair<String, String> parts = StringUtils.formatElevation(getContext(), altitude, metricUnits);
-
-            elevationValue.setText(parts.first);
-            elevationUnit.setText(parts.second);
+            elevationCurrentValue.setText(parts.first);
+            elevationCurrentUnit.setText(parts.second);
         }
 
         // Set coordinate

src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java

@@ -49,6 +49,7 @@ import de.dennisguse.opentracks.content.sensor.SensorDataSet;
 import de.dennisguse.opentracks.services.handlers.GpsStatusValue;
 import de.dennisguse.opentracks.services.handlers.HandlerServer;
 import de.dennisguse.opentracks.services.sensors.BluetoothRemoteSensorManager;
+import de.dennisguse.opentracks.services.sensors.ElevationSumManager;
 import de.dennisguse.opentracks.services.tasks.AnnouncementPeriodicTaskFactory;
 import de.dennisguse.opentracks.services.tasks.PeriodicTaskExecutor;
 import de.dennisguse.opentracks.stats.TrackStatistics;
@@ -115,6 +116,7 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
     // The following variables are set when recording:
     private WakeLock wakeLock;
     private BluetoothRemoteSensorManager remoteSensorManager;
+    private ElevationSumManager elevationSumManager;
 
     private TrackStatisticsUpdater trackStatisticsUpdater;
     private TrackPoint lastTrackPoint;
@@ -174,6 +176,11 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             remoteSensorManager = null;
         }
 
+        if (elevationSumManager != null) {
+            elevationSumManager.stop(this);
+            elevationSumManager = null;
+        }
+
         // Reverse order from onCreate
         showNotification(false); //TODO Why?
 
@@ -371,6 +378,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         // Update instance variables
         remoteSensorManager = new BluetoothRemoteSensorManager(this);
         remoteSensorManager.start();
+
+        elevationSumManager = new ElevationSumManager();
+        elevationSumManager.start(this);
+
         lastTrackPoint = null;
         isIdle = false;
 
@@ -456,6 +467,11 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             remoteSensorManager.stop();
             remoteSensorManager = null;
         }
+        if (elevationSumManager != null) {
+            elevationSumManager.stop(this);
+            elevationSumManager = null;
+        }
+
         lastTrackPoint = null;
 
         handlerServer.stop(this);
@@ -533,6 +549,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         //TODO Figure out how to avoid loading the lastValidTrackPoint from the database
         TrackPoint lastValidTrackPoint = getLastValidTrackPointInCurrentSegment(track.getId());
 
+        if (elevationSumManager != null) {
+            trackPoint.setElevationGain(elevationSumManager.getElevationGain_m());
+        }
+
         //Storing trackPoint
 
         // Always insert the first segment location
@@ -556,15 +576,19 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             insertTrackPoint(track, TrackPoint.createPause());
 
             insertTrackPoint(track, trackPoint);
-            isIdle = false;
+            elevationSumManager.reset();
 
+            isIdle = false;
             lastTrackPoint = trackPoint;
             return;
         }
 
         if (trackPoint.hasSensorData() || distanceToLastTrackLocation >= recordingDistanceInterval) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = false;
 
             lastTrackPoint = trackPoint;
@@ -573,7 +597,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
 
         if (!isIdle && !TrackPointUtils.isMoving(trackPoint)) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = true;
 
             lastTrackPoint = trackPoint;
@@ -582,7 +609,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
 
         if (isIdle && TrackPointUtils.isMoving(trackPoint)) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = false;
 
             lastTrackPoint = trackPoint;
@@ -672,6 +702,17 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         }
     }
 
+    /**
+     * Returns the relative elevation gain (since last trackpoint).
+     */
+    Float getElevationGain_m() {
+        if (elevationSumManager == null || !elevationSumManager.isConnected()) {
+            return null;
+        }
+
+        return elevationSumManager.getElevationGain_m();
+    }
+
     private void showNotification(boolean isGpsStarted) {
         if (isRecording()) {
             Intent intent = IntentUtils.newIntent(this, TrackRecordingActivity.class)

src/main/java/de/dennisguse/opentracks/services/TrackRecordingServiceBinder.java

@@ -99,6 +99,11 @@ class TrackRecordingServiceBinder extends android.os.Binder implements TrackReco
         return trackRecordingService.getSensorDataSet();
     }
 
+    @Override
+    public Float getElevationGain_m() {
+        return trackRecordingService.getElevationGain_m();
+    }
+
     @VisibleForTesting
     @Override
     public void setRemoteSensorManager(BluetoothRemoteSensorManager remoteSensorManager) {

src/main/java/de/dennisguse/opentracks/services/TrackRecordingServiceInterface.java

@@ -65,12 +65,19 @@ public interface TrackRecordingServiceInterface {
     Marker.Id insertMarker(String name, String category, String description, String photoUrl);
 
     /**
-     * Gets the current sensor data. Returns null if there is no data.
+     * Gets the current sensor data.
      *
-     * @return SensorDataSet object.
+     * @return SensorDataSet object or null.
      */
     SensorDataSet getSensorData();
 
+    /**
+     * Gets the current elevation gain.
+     *
+     * @return elevation gain in m or null.
+     */
+    Float getElevationGain_m();
+
     @VisibleForTesting
     void setRemoteSensorManager(BluetoothRemoteSensorManager remoteSensorManager);
 

src/main/java/de/dennisguse/opentracks/services/sensors/ElevationSumManager.java

@@ -0,0 +1,102 @@
+package de.dennisguse.opentracks.services.sensors;
+
+import android.content.Context;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.util.Log;
+
+import androidx.annotation.VisibleForTesting;
+
+import de.dennisguse.opentracks.util.PressureSensorUtils;
+import de.dennisguse.opentracks.util.UnitConversions;
+
+/**
+ * Estimates the elevation gain and elevation loss using the device's pressure sensor (i.e., barometer).
+ */
+public class ElevationSumManager implements SensorEventListener {
+
+    private static final String TAG = ElevationSumManager.class.getSimpleName();
+
+    private static final int SAMPLING_RATE = 3 * (int) UnitConversions.ONE_SECOND_US;
+
+    private boolean isConnected = false;
+
+    private float lastUsedPressureValue_hPa;
+
+    private float elevationGain_m;
+    private float elevationLoss_m;
+
+    public void start(Context context) {
+        SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+
+        Sensor pressureSensor = sensorManager.getDefaultSensor(Sensor.TYPE_PRESSURE);
+        if (pressureSensor == null) {
+            Log.w(TAG, "No pressure sensor available.");
+            isConnected = false;
+        }
+
+        isConnected = sensorManager.registerListener(this, pressureSensor, SAMPLING_RATE);
+        lastUsedPressureValue_hPa = Float.NaN;
+        reset();
+    }
+
+    public void stop(Context context) {
+        Log.d(TAG, "Stop");
+
+        SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+        sensorManager.unregisterListener(this);
+
+        isConnected = false;
+        reset();
+    }
+
+    public boolean isConnected() {
+        return isConnected;
+    }
+
+    public float getElevationGain_m() {
+        return elevationGain_m;
+    }
+
+    public float getElevationLoss_m() {
+        return elevationLoss_m;
+    }
+
+    public void reset() {
+        Log.d(TAG, "Reset");
+        elevationGain_m = 0;
+        elevationLoss_m = 0;
+    }
+
+    @Override
+    public void onAccuracyChanged(Sensor sensor, int accuracy) {
+        Log.w(TAG, "Sensor accuracy changes are (currently) ignored.");
+    }
+
+    @Override
+    public void onSensorChanged(SensorEvent event) {
+        onSensorValueChanged(event.values[0]);
+    }
+
+    @VisibleForTesting
+    void onSensorValueChanged(float value_hPa) {
+        if (Float.isNaN(lastUsedPressureValue_hPa)) {
+            lastUsedPressureValue_hPa = value_hPa;
+            return;
+        }
+
+        PressureSensorUtils.ElevationChange elevationChange = PressureSensorUtils.computeChanges_m(lastUsedPressureValue_hPa, value_hPa);
+        if (elevationChange != null) {
+            if (elevationChange.getElevationChange_m() > 0) {
+                elevationGain_m += elevationChange.getElevationChange_m();
+            } else {
+                elevationLoss_m += elevationChange.getElevationChange_m();
+            }
+            lastUsedPressureValue_hPa = elevationChange.getCurrentSensorValue_hPa();
+        }
+
+        Log.v(TAG, "elevation gain: " + elevationGain_m);
+    }
+}

src/main/java/de/dennisguse/opentracks/stats/TrackStatistics.java

@@ -228,7 +228,7 @@ public class TrackStatistics {
     }
 
     /**
-     * Gets the total elevation gain in meters. This is calculated as the sum of all positive differences in the smoothed elevation.
+     * Gets the total elevation gain in meters.
      */
     public double getTotalElevationGain() {
         return totalElevationGain_m;

src/main/java/de/dennisguse/opentracks/stats/TrackStatisticsUpdater.java

@@ -112,7 +112,7 @@ public class TrackStatisticsUpdater {
      * Adds a trackPoint.
      * TODO: This assume trackPoint has a valid time.
      *
-     * @param trackPoint             the trackPoint
+     * @param trackPoint           the trackPoint
      * @param minRecordingDistance the min recording distance
      */
     public void addTrackPoint(TrackPoint trackPoint, int minRecordingDistance) {
@@ -134,8 +134,16 @@ public class TrackStatisticsUpdater {
             return;
         }
 
-        //TODO Use Barometer to compute elevation gain.
-        double elevationDifference = trackPoint.hasAltitude() ? updateElevation(trackPoint.getAltitude()) : 0.0;
+        //Update absolute (GPS-based) elevation
+        if (trackPoint.hasAltitude()) {
+            updateAbsoluteElevation(trackPoint.getAltitude());
+        }
+
+        //Get elevation gain
+        if (trackPoint.hasElevationGain()) {
+            currentSegment.addTotalElevationGain(trackPoint.getElevationGain());
+            Log.d(TAG, "elevation gain: " + trackPoint.getElevationGain());
+        }
 
         if (lastTrackPoint == null || lastMovingTrackPoint == null) {
             lastTrackPoint = trackPoint;
@@ -207,23 +215,21 @@ public class TrackStatisticsUpdater {
     }
 
     /**
-     * Updates an elevation reading. Returns the difference.
+     * Updates an elevation reading.
      *
      * @param elevation the elevation
+     * @return the difference
      */
     @VisibleForTesting
-    private double updateElevation(double elevation) {
+    private double updateAbsoluteElevation(double elevation) {
         // Update elevation using the smoothed average
         double oldAverage = elevationBuffer_m.getAverage();
         elevationBuffer_m.setNext(elevation);
         double newAverage = elevationBuffer_m.getAverage();
 
         currentSegment.updateElevationExtremities(newAverage);
-        double difference = newAverage - oldAverage;
-        if (difference > 0) {
-            currentSegment.addTotalElevationGain(difference);
-        }
-        return difference;
+
+        return newAverage - oldAverage;
     }
 
     private TrackStatistics init(long time) {

src/main/java/de/dennisguse/opentracks/util/PressureSensorUtils.java

@@ -0,0 +1,49 @@
+package de.dennisguse.opentracks.util;
+
+import android.hardware.SensorManager;
+
+public class PressureSensorUtils {
+
+    //Everything above is considered a meaningful change in elevation.
+    private static float ELEVATION_CHANGE_DIFF_M = 5.0f;
+
+    private PressureSensorUtils() {
+    }
+
+    public static class ElevationChange {
+
+        private float currentSensorValue_hPa;
+
+        private float elevationChange_m;
+
+        public ElevationChange(float currentSensorValue_hPa, float elevationChange_m) {
+            this.currentSensorValue_hPa = currentSensorValue_hPa;
+            this.elevationChange_m = elevationChange_m;
+        }
+
+        public float getCurrentSensorValue_hPa() {
+            return currentSensorValue_hPa;
+        }
+
+        public float getElevationChange_m() {
+            return elevationChange_m;
+        }
+    }
+
+    /**
+     * Computes the elevation gain and elevation loss.
+     *
+     * @return null if no meaningful elevation change occurred.
+     */
+    public static ElevationChange computeChanges_m(float lastSensorValue_hPa, float currentSensorValue_hPa) {
+        float lastSensorValue_m = SensorManager.getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, lastSensorValue_hPa);
+        float currentSensorValue_m = SensorManager.getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, currentSensorValue_hPa);
+
+        float elevationChange_m = currentSensorValue_m - lastSensorValue_m;
+        if (Math.abs(elevationChange_m) < ELEVATION_CHANGE_DIFF_M) {
+            return null;
+        }
+
+        return new ElevationChange(currentSensorValue_hPa, elevationChange_m);
+    }
+}

src/main/java/de/dennisguse/opentracks/util/UnitConversions.java

@@ -26,7 +26,8 @@ public class UnitConversions {
     public static final long S_TO_MS = 1000;
 
     // Time
-    // 1 second in milliseconds
+    // TODO Use int instead of long.
+    public static final long ONE_SECOND_US = UnitConversions.S_TO_MS * 1000;
     public static final long ONE_SECOND_MS = UnitConversions.S_TO_MS;
     public static final long ONE_MINUTE_MS = (long) (UnitConversions.MIN_TO_S * UnitConversions.S_TO_MS);
     public static final long ONE_HOUR_MS = 60 * ONE_MINUTE_MS;