Method onCharacteristicChanged

android/src/BluetoothSensor.java:165–222

(BluetoothGatt gatt,
                                                   BluetoothGattCharacteristic c)

  }

  @Override
  public synchronized void onCharacteristicChanged(BluetoothGatt gatt,
                                                   BluetoothGattCharacteristic c) {
    if (!safeDestruct.increment())
      return;

    try {
      if (BluetoothUuids.HEART_RATE_SERVICE.equals(c.getService().getUuid())) {
        if (BluetoothUuids.HEART_RATE_MEASUREMENT_CHARACTERISTIC.equals(c.getUuid())) {
          readHeartRateMeasurement(c);
        }
      }

      if (BluetoothUuids.FLYTEC_SENSBOX_SERVICE.equals(c.getService().getUuid())) {
        if (BluetoothUuids.FLYTEC_SENSBOX_NAVIGATION_SENSOR_CHARACTERISTIC.equals(c.getUuid())) {
          /* protocol documentation:
             https://github.com/flytec/SensBoxLib_iOS/blob/master/_SensBox%20Documentation/SensorBox%20BLE%20Protocol.pdf */
          final int gps_status = c.getIntValue(c.FORMAT_UINT8, 18) & 0x7;
          final boolean hasAltitude = (gps_status == 2 || gps_status == 4);

          final long time = 1000 *
            toUnsignedLong(c.getIntValue(c.FORMAT_UINT32, 0));

          listener.onLocationSensor(time,
                                    flytecSatellites,
                                    c.getIntValue(c.FORMAT_SINT32, 8) / 10000000.,
                                    c.getIntValue(c.FORMAT_SINT32, 4) / 10000000.,
                                    hasAltitude, true,
                                    c.getIntValue(c.FORMAT_SINT16, 12),
                                    haveFlytecMovement, flytecTrack,
                                    haveFlytecMovement, flytecGroundSpeed,
                                    false, 0);

          listener.onPressureAltitudeSensor(c.getIntValue(c.FORMAT_SINT16, 14));
        } else if (BluetoothUuids.FLYTEC_SENSBOX_MOVEMENT_SENSOR_CHARACTERISTIC.equals(c.getUuid())) {
          flytecGroundSpeed = c.getIntValue(c.FORMAT_SINT16, 6) / 10.;
          flytecTrack = c.getIntValue(c.FORMAT_SINT16, 8) / 10.;

          listener.onVarioSensor(c.getIntValue(c.FORMAT_SINT16, 4) / 100.f);
          listener.onAccelerationSensor1(c.getIntValue(c.FORMAT_UINT16, 16) / 10.);

          haveFlytecMovement = true;
        } else if (BluetoothUuids.FLYTEC_SENSBOX_SECOND_GPS_CHARACTERISTIC.equals(c.getUuid())) {
          flytecSatellites = c.getIntValue(c.FORMAT_UINT8, 6);
        } else if (BluetoothUuids.FLYTEC_SENSBOX_SYSTEM_CHARACTERISTIC.equals(c.getUuid())) {
          listener.onBatteryPercent(c.getIntValue(c.FORMAT_UINT8, 4));

          final double CELSIUS_OFFSET = 273.15;
          double temperatureCelsius = c.getIntValue(c.FORMAT_SINT16, 6) / 10.;
          listener.onTemperature(CELSIUS_OFFSET + temperatureCelsius);
        }
      }
    } catch (NullPointerException e) {
      /* probably caused by a malformed value - ignore */
    } finally {
      safeDestruct.decrement();
    }
  }