@Override
 public void connect(String username, String robotBtName, String robotBtAddr) {
   super.connect(username, robotBtName, robotBtAddr);
   robotController = new RobotBtController(username, robotBtName, robotBtAddr);
   if (robotController.startConnection()) {
     try {
       Thread.sleep(1000);
     } catch (InterruptedException e) {
       e.printStackTrace();
     }
     mCurrentState = STATE_SUCCESS;
   } else {
     mCurrentState = STATE_BLUETOOTH_FAIL;
   }
 }
 @Override
 public void sendCommand(String cmd) {
   super.sendCommand(cmd);
   if (robotController != null && mCurrentState == STATE_SUCCESS) robotController.write(cmd);
 }
 @Override
 public void disconnect() {
   super.disconnect();
   if (robotController != null) robotController.disconnect();
 }