How to access the methods of my Bluetooth service?

I have an application that from the MainAcivity increases or excretes a int Grados depending on which button is pressed, the add or subtract.

Since BluetoothActivity turned on and off the Bluetooth and launched a service that handles the bluetooth connection with any device, the problem is that I do not know how to send from Bluetooth activity or from MainActivity that variable int Grados .

This class is in a BluetoothService extends Service that is launched with

Intent intentBTService = new Intent(BluetoothActivity.this,BluetoothService_Test.class);
            intentBTService.putExtra("device_address",address);
            startService(intentBTService);

Lega to onStarCommand

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    //Log.d(TAG, "Servicio iniciado...")
    //if(intent != null){}
    Message msg = mServiceHandler.obtainMessage();
    msg.arg1 = startId;
    msg.obj = intent;
    mServiceHandler.sendMessage(msg);
    return START_NOT_STICKY;
}

And from there to a handler that handles the process in background

private final class CountHandler extends Handler{
    CountHandler(Looper looper){
        super(looper);
    }
    @Override
    public void handleMessage(Message msg){
        Intent request = (Intent) msg.obj;
        String address = request.getStringExtra("device_address");
        int starId =msg.arg1;
        if (address != null){
            mBluetoothAdapter =BluetoothAdapter.getDefaultAdapter();
            mBTDevice = mBluetoothAdapter.getRemoteDevice(address);
            connect(mBTDevice);

        }
    }
}

@Override
public void onCreate() {
    super.onCreate();
    HandlerThread backgroundThread  = new HandlerThread("CounterThread",
            Process.THREAD_PRIORITY_BACKGROUND);
    backgroundThread .start();
    mServiceHandler =  new CountHandler(backgroundThread.getLooper());
    localBroadcastManager = LocalBroadcastManager.getInstance(getApplicationContext());
}

This is the class where reading and writing are handled

private class ConnectedThread extends Thread{
   // private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;
    public ConnectedThread(BluetoothSocket socket){

        mBTSocket = socket;
        //mmSocket = socket;
        InputStream tempIn = null;
        OutputStream temOut = null;

        try {
            tempIn = mBTSocket.getInputStream();
            temOut = mBTSocket.getOutputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        mmInStream = tempIn;
        mmOutStream = temOut;
        mState = S_STATE_CONNECTED;


        mState = S_STATE_CONNECTED;
        String nameDevice = mBTDevice.getName();
        String nameAddress = mBTDevice.getAddress();
        Intent resultIntent = new Intent(ACTION_BT_SERVICE_CONNECTED);
        resultIntent.putExtra("addressDevice",nameAddress);
        resultIntent.putExtra("nameDevice",nameDevice);
        localBroadcastManager.sendBroadcast(resultIntent);
    }

    public void run(){
        byte[] buffer = new byte[1024];
        int bytes;

        while (mState == S_STATE_CONNECTED ){
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);
                //bytes = mmInStream.available();
                // Send the obtained bytes to the UI Activity
                if(bytes != 0) {
                    //Mensaje recibido
                    //mServiceHandler.obtainMessage(STATE_MESSAGE_RECIVED,bytes,-1,buffer).sendToTarget();
                }
            } catch (IOException e) {
                e.printStackTrace();
                connectionLost();
                break;
            }
        }
    }
    public void write(byte[] bytes ) {
                //converts entered String into bytes
        try {
            mmOutStream.write(bytes);
            //mmOutStream.write(bytes);
        } catch (IOException e) {
            connectionFailed();
        }
    }
    //Call this from the main activity to shutdown the connection
    public void cancel() {
        try {
            mBTSocket.close();

        } catch (IOException e) {

        }
    }
}

Inside connect are the other methods to connect the socket and others, what I want is to know how to access the write method of ConnectedThread from an activity to send my int Grados to an arduino for example