@Override
 protected void onPause() {
   if (mSensorManager != null) stopAccelerometer();
   super.onDestroy();
   // unregisterReceiver(mMessageUpdateReceiver);
   super.onPause();
 }
  @Override
  public void onDestroy() {
    if (mAsyncTask != null) {
      mAsyncTask.cancel(true);
      try {
        Thread.sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
    if (mSensorManager != null) stopAccelerometer();
    super.onDestroy();

    try {
      mRawAccOutputStream.close();
    } catch (Exception ex) {
    }
  }