@Override
  public void startListening() {
    if (isListening) return;

    isListening =
        sensorManager.registerListener(
            this, accelorometerSensor, SensorManager.SENSOR_DELAY_NORMAL);

    if (isListening) binder.onArmed();
  }
 public void updateBinder() {
   if (hasBeenTripped) binder.onTripped();
   else if (isListening) binder.onArmed();
   else binder.onDisarmed();
 }