Как отправить этот hexcode в bluetooth

Question

public String colorHex(int color) {

    int a = Color.alpha(color);
    int r = Color.red(color);
    int g = Color.green(color);
    int b = Color.blue(color);
    return String.format(Locale.getDefault(), "0x%02X%02X%02X%02X", a, r, g, b);
}

У меня есть код выше, и я не могу на всю жизнь понять, как (одним нажатием кнопки) отправить этот гекс-код через Bluetooth на Arduino. любая помощь будет отличной.

edit: у меня настроен и работает код bluetooth ie. я могу подключиться к arudino.

ниже приведен код Bluetooth, который я использую.

Я использую палитру цветов в отдельном классе и призываю к активности Bluetooth. просто не могу решить, как отправить шестнадцатеричный код в виде строки через соединение Bluetooth

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mInstanceActivity = this;


    mBluetoothStatus = findViewById(R.id.bluetoothStatus);
    mReadBuffer = findViewById(R.id.readBuffer);
    mScanBtn = findViewById(R.id.scan);
    mOffBtn = findViewById(R.id.off);
    mDiscoverBtn = findViewById(R.id.discover);
    mListPairedDevicesBtn = findViewById(R.id.PairedBtn);

    mBTArrayAdapter = new ArrayAdapter<String>(this, 
android.R.layout.simple_list_item_1);
    mBTAdapter = BluetoothAdapter.getDefaultAdapter(); // get a handle on 
the bluetooth radio

    mDevicesListView = findViewById(R.id.devicesListView);
    mDevicesListView.setAdapter(mBTArrayAdapter); // assign model to view
    mDevicesListView.setOnItemClickListener(mDeviceClickListener);

    Button btn = findViewById(R.id.NextPage);

    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(MainActivity.this, Palette.class));

        }});


    mHandler = new Handler(){
        @RequiresApi(api = Build.VERSION_CODES.KITKAT)
        public void handleMessage(android.os.Message msg){
            if(msg.what == MESSAGE_READ){
                String readMessage = null;
                readMessage = new String((byte[]) msg.obj, 
StandardCharsets.UTF_8);
                mReadBuffer.setText(readMessage);
            }

            if(msg.what == CONNECTING_STATUS){
                if(msg.arg1 == 1)
                    mBluetoothStatus.setText("Connected to Device: " + 
msg.obj);
                else
                    mBluetoothStatus.setText("Connection Failed");
            }
        }
    };










    if (mBTArrayAdapter == null) {
        // Device does not support Bluetooth
        mBluetoothStatus.setText("Status: Bluetooth not found");
        Toast.makeText(getApplicationContext(),"Bluetooth device not 
found!",Toast.LENGTH_SHORT).show();
    }



        mScanBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                bluetoothOn(v);
            }
        });

        mOffBtn.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                bluetoothOff(v);
            }
        });

        mListPairedDevicesBtn.setOnClickListener(new View.OnClickListener() 
{
            @Override
            public void onClick(View v){
                listPairedDevices(v);
            }
        });

        mDiscoverBtn.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                discover(v);
            }
        });
    }


private void bluetoothOn(View view){
    if (!mBTAdapter.isEnabled()) {
        Intent enableBtIntent = new 
Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        mBluetoothStatus.setText("Bluetooth enabled");
        Toast.makeText(getApplicationContext(),"Bluetooth turned 
on",Toast.LENGTH_SHORT).show();

    }
    else{
        Toast.makeText(getApplicationContext(),"Bluetooth is already on", 
Toast.LENGTH_SHORT).show();
    }
}

// Enter here after user selects "yes" or "no" to enabling radio
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent 
Data){
    // Check which request we're responding to
    if (requestCode == REQUEST_ENABLE_BT) {
        // Make sure the request was successful
        if (resultCode == RESULT_OK) {
            // The user picked a contact.
            // The Intent's data Uri identifies which contact was selected.
            mBluetoothStatus.setText("Enabled");
        }
        else
            mBluetoothStatus.setText("Disabled");
    }
}

private void bluetoothOff(View view){
    mBTAdapter.disable(); // turn off
    mBluetoothStatus.setText("Bluetooth disabled");
    Toast.makeText(getApplicationContext(),"Bluetooth turned Off", 
Toast.LENGTH_SHORT).show();
}

private void discover(View view){
    // Check if the device is already discovering
    if(mBTAdapter.isDiscovering()){
        mBTAdapter.cancelDiscovery();
        Toast.makeText(getApplicationContext(),"Discovery 
stopped",Toast.LENGTH_SHORT).show();
    }
    else{
        if(mBTAdapter.isEnabled()) {
            mBTArrayAdapter.clear(); // clear items
            mBTAdapter.startDiscovery();
            Toast.makeText(getApplicationContext(), "Discovery started", 
Toast.LENGTH_SHORT).show();
            registerReceiver(blReceiver, new 
IntentFilter(BluetoothDevice.ACTION_FOUND));
        }
        else{
            Toast.makeText(getApplicationContext(), "Bluetooth not on", 
Toast.LENGTH_SHORT).show();
        }
    }
}

final BroadcastReceiver blReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if(BluetoothDevice.ACTION_FOUND.equals(action)){
            BluetoothDevice device = 
intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            // add the name to the list
            mBTArrayAdapter.add(device.getName() + "\n" + 
device.getAddress());
            mBTArrayAdapter.notifyDataSetChanged();
        }
    }
};

private void listPairedDevices(View view){
    mPairedDevices = mBTAdapter.getBondedDevices();
    if(mBTAdapter.isEnabled()) {
        // put it's one to the adapter
        for (BluetoothDevice device : mPairedDevices)
            mBTArrayAdapter.add(device.getName() + "\n" + 
device.getAddress());

         Toast.makeText(getApplicationContext(), "Show Paired Devices", 
Toast.LENGTH_SHORT).show();
    }
    else
        Toast.makeText(getApplicationContext(), "Bluetooth not on", 
Toast.LENGTH_SHORT).show();
}

private AdapterView.OnItemClickListener mDeviceClickListener = new 
AdapterView.OnItemClickListener() {
    public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) 
{

        if(!mBTAdapter.isEnabled()) {
            Toast.makeText(getBaseContext(), "Bluetooth not on", 
Toast.LENGTH_SHORT).show();
            return;
        }

        mBluetoothStatus.setText("Connecting...");
        // Get the device MAC address, which is the last 17 chars in the 
View
        String info = ((TextView) v).getText().toString();
        final String address = info.substring(info.length() - 17);
        final String name = info.substring(0,info.length() - 17);


        // Spawn a new thread to avoid blocking the GUI one
        new Thread()
        {
            public void run() {
                boolean fail = false;

                BluetoothDevice device = 
mBTAdapter.getRemoteDevice(address);

                try {
                    mBTSocket = createBluetoothSocket(device);
                } catch (IOException e) {
                    fail = true;
                    Toast.makeText(getBaseContext(), "Socket creation 
failed", Toast.LENGTH_SHORT).show();
                }
                // Establish the Bluetooth socket connection.
                try {
                    mBTSocket.connect();
                } catch (IOException e) {
                    try {
                        fail = true;
                        mBTSocket.close();
                        mHandler.obtainMessage(CONNECTING_STATUS, -1, -1)
                                .sendToTarget();
                    } catch (IOException e2) {
                        //insert code to deal with this
                        Toast.makeText(getBaseContext(), "Socket creation 
failed", Toast.LENGTH_SHORT).show();
                    }
                }
                if(fail == false) {
                    mConnectedThread = new ConnectedThread(mBTSocket);
                    mConnectedThread.start();

                    mHandler.obtainMessage(CONNECTING_STATUS, 1, -1, name)
                            .sendToTarget();
                }
            }
        }.start();
    }
};

private BluetoothSocket createBluetoothSocket(BluetoothDevice device) 
throws IOException {
    return  device.createRfcommSocketToServiceRecord(BTMODULEUUID);
    //creates secure outgoing connection with BT device using UUID
}

public class ConnectedThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket) {
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) { }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        byte[] buffer = new byte[1024];  // buffer store for the stream
        int bytes; // bytes returned from read()
        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.available();
                if(bytes != 0) {
                     SystemClock.sleep(100); //pause and wait for rest of 
data. Adjust this depending on your sending speed.
                    bytes = mmInStream.available(); // how many bytes are 
ready to be read?
                    bytes = mmInStream.read(buffer, 0, bytes); // record 
how many bytes we actually read
                    mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                            .sendToTarget(); // Send the obtained bytes to 
the UI activity
                }
            } catch (IOException e) {
                e.printStackTrace();

                break;
            }
        }
    }

    /* Call this from the main activity to send data to the remote device 
*/
    public void write(String input) {
        byte[] bytes = input.getBytes();           //converts entered 
String into bytes
        try {
            mmOutStream.write(bytes);
        } catch (IOException e) { }
    }

    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
protected void onDestroy(){
    super.onDestroy();
    mInstanceActivity = null;

}

}

, и я пытаюсь отправить шестнадцатеричный код со следующей код:

SendColor.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v){
            if(mConnectedThread != null) //First check to make sure thread 
created
                mConnectedThread.write(colorHex());
        }
    });