public abstract class CameraActivity extends AppCompatActivity implements OnImageAvailableListener, Camera.PreviewCallback, CompoundButton.OnCheckedChangeListener, View.OnClickListener {
//////////////////////////////////////////////////////////////////////////////
  String address = null , name=null;

  BluetoothAdapter myBluetooth = null;
  BluetoothSocket btSocket = null;
  Set<BluetoothDevice> pairedDevices;
  static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
//////////////////////////////////////////////////////////////////////////////
  private static final Logger LOGGER = new Logger();

  private static final int PERMISSIONS_REQUEST = 1;

  private static final String PERMISSION_CAMERA = Manifest.permission.CAMERA;

  ...

  @Override
  protected void onCreate(final Bundle savedInstanceState) {
    LOGGER.d("onCreate " + this);
    super.onCreate(null);
//////////////////////////////////////////////////////////////////////////////
    try {setw();} catch (Exception e) {}
//////////////////////////////////////////////////////////////////////////////
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

    setContentView(R.layout.activity_camera);
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(false);

    if (hasPermission()) {
      setFragment();
    } else {
      requestPermission();
    }

    ...

    ...

  }
//////////////////////////////////////////////////////////////////////////////
  @SuppressLint("ClickableViewAccessibility")
  private void setw() throws IOException {
    bluetooth_connect_device();
  }

  private void bluetooth_connect_device() throws IOException
  {
    try
    {
      myBluetooth = BluetoothAdapter.getDefaultAdapter();
      address = myBluetooth.getAddress();
      pairedDevices = myBluetooth.getBondedDevices();
      if (pairedDevices.size()>0)
      {
        for(BluetoothDevice bt : pairedDevices)
        {
          address=bt.getAddress().toString();name = bt.getName().toString();
          Toast.makeText(getApplicationContext(),"Connected", Toast.LENGTH_SHORT).show();

        }
      }

    }
    catch(Exception we){}
    myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device
    BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available
    btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection
    btSocket.connect();
    try {}
    catch(Exception e){}
  }

  public void write(String s) throws IOException {
    btSocket.getOutputStream().write(s.getBytes());
  }

//////////////////////////////////////////////////////////////////////////////

public synchronized void draw(final Canvas canvas) throws IOException, InterruptedException {
    final boolean rotated = sensorOrientation % 180 == 90;
    final float multiplier =
        Math.min(
            canvas.getHeight() / (float) (rotated ? frameWidth : frameHeight),
            canvas.getWidth() / (float) (rotated ? frameHeight : frameWidth));
    frameToCanvasMatrix =
        ImageUtils.getTransformationMatrix(
            frameWidth,
            frameHeight,
            (int) (multiplier * (rotated ? frameHeight : frameWidth)),
            (int) (multiplier * (rotated ? frameWidth : frameHeight)),
            sensorOrientation,
            false);
    for (final TrackedRecognition recognition : trackedObjects) {
      final RectF trackedPos = new RectF(recognition.location);

      getFrameToCanvasMatrix().mapRect(trackedPos);
      boxPaint.setColor(recognition.color);

      float cornerSize = Math.min(trackedPos.width(), trackedPos.height()) / 8.0f;
      canvas.drawRoundRect(trackedPos, cornerSize, cornerSize, boxPaint);

      final String labelString =
          !TextUtils.isEmpty(recognition.title)
              ? String.format("%s %.0f %.0f %.2f", recognition.title, trackedPos.centerX(), trackedPos.centerY(), (100 * recognition.detectionConfidence))
              : String.format("%.2f", (100 * recognition.detectionConfidence));

      borderedText.drawText(
          canvas, trackedPos.left + cornerSize, trackedPos.top, labelString + '%' , boxPaint);
//////////////////////////////////////////////////////////////////////////////
      if(recognition.title == "person" && (100 * recognition.detectionConfidence) > 40)
      {
        cameraActivity.write(Integer.toString(Math.round(trackedPos.centerY())));
      }
//////////////////////////////////////////////////////////////////////////////
    }
  }