Sunday, July 19, 2015

Android Bluetooth to control LED brightness on Arduino Due + HC-06

Previous exercise "Android example to communicate with Bluetooth device, HC-06 Bluetooth Module" show how to send string. Here we implement our command format, such that we can use SeekBar on Android to control brightness of the Arduino Due on-board LED (pin 13), via Bluetooth to HC-06 Bluetooth Module.



Android Side:

com.example.androidbtcontrol.MainActivity.java
/*
Android Example to connect to and communicate with Bluetooth
In this exercise, the target is a Arduino Due + HC-06 (Bluetooth Module)

 */
package com.example.androidbtcontrol;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;


public class MainActivity extends ActionBarActivity {

    private static final int REQUEST_ENABLE_BT = 1;

    BluetoothAdapter bluetoothAdapter;

    ArrayList<BluetoothDevice> pairedDeviceArrayList;

    TextView textInfo, textStatus;
    ListView listViewPairedDevice;
    LinearLayout inputPane;

    SeekBar barAnalogOut;

    ArrayAdapter<BluetoothDevice> pairedDeviceAdapter;
    private UUID myUUID;
    private final String UUID_STRING_WELL_KNOWN_SPP =
        "00001101-0000-1000-8000-00805F9B34FB";

    ThreadConnectBTdevice myThreadConnectBTdevice;
    ThreadConnected myThreadConnected;

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

        textInfo = (TextView)findViewById(R.id.info);
        textStatus = (TextView)findViewById(R.id.status);
        listViewPairedDevice = (ListView)findViewById(R.id.pairedlist);

        inputPane = (LinearLayout)findViewById(R.id.inputpane);

        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)){
            Toast.makeText(this,
                    "FEATURE_BLUETOOTH NOT support",
                    Toast.LENGTH_LONG).show();
            finish();
            return;
        }

        //using the well-known SPP UUID
        myUUID = UUID.fromString(UUID_STRING_WELL_KNOWN_SPP);

        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (bluetoothAdapter == null) {
            Toast.makeText(this,
                    "Bluetooth is not supported on this hardware platform",
                    Toast.LENGTH_LONG).show();
            finish();
            return;
        }

        String stInfo = bluetoothAdapter.getName() + "\n" +
                bluetoothAdapter.getAddress();
        textInfo.setText(stInfo);

        barAnalogOut = (SeekBar)findViewById(R.id.analogOut);
        barAnalogOut.setOnSeekBarChangeListener(OnAnalogOutChangeListener);

    }

    SeekBar.OnSeekBarChangeListener OnAnalogOutChangeListener =
            new SeekBar.OnSeekBarChangeListener(){
                @Override
                public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                    //will generate too much data sent!
                    //SendAnalogOut(progress);
                }

                @Override
                public void onStartTrackingTouch(SeekBar seekBar) {

                }

                @Override
                public void onStopTrackingTouch(SeekBar seekBar) {
                    SendAnalogOut(seekBar.getProgress());
                }
            };

    private final byte SYNC_BYTE = (byte) 0xAA;
    private final byte LENGTH_ANALOG = (byte) 3;
    private final byte CMD_ANALOG = (byte) 1;

    private void SendAnalogOut(int val){
        byte[] bytesToSend = {SYNC_BYTE, LENGTH_ANALOG, CMD_ANALOG, (byte) val};
        myThreadConnected.write(bytesToSend);
    }

    @Override
    protected void onStart() {
        super.onStart();

        //Turn ON BlueTooth if it is OFF
        if (!bluetoothAdapter.isEnabled()) {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
        }

        setup();
    }

    private void setup() {
        Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            pairedDeviceArrayList = new ArrayList<BluetoothDevice>();

            for (BluetoothDevice device : pairedDevices) {
                pairedDeviceArrayList.add(device);
            }

            pairedDeviceAdapter = new ArrayAdapter<BluetoothDevice>(this,
                    android.R.layout.simple_list_item_1, pairedDeviceArrayList);
            listViewPairedDevice.setAdapter(pairedDeviceAdapter);

            listViewPairedDevice.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    BluetoothDevice device =
                            (BluetoothDevice) parent.getItemAtPosition(position);
                    Toast.makeText(MainActivity.this,
                            "Name: " + device.getName() + "\n"
                                    + "Address: " + device.getAddress() + "\n"
                                    + "BondState: " + device.getBondState() + "\n"
                                    + "BluetoothClass: " + device.getBluetoothClass() + "\n"
                                    + "Class: " + device.getClass(),
                            Toast.LENGTH_LONG).show();

                    textStatus.setText("start ThreadConnectBTdevice");
                    myThreadConnectBTdevice = new ThreadConnectBTdevice(device);
                    myThreadConnectBTdevice.start();
                }
            });
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if(myThreadConnectBTdevice!=null){
            myThreadConnectBTdevice.cancel();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(requestCode==REQUEST_ENABLE_BT){
            if(resultCode == Activity.RESULT_OK){
                setup();
            }else{
                Toast.makeText(this,
                        "BlueTooth NOT enabled",
                        Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }

    //Called in ThreadConnectBTdevice once connect successed
    //to start ThreadConnected
    private void startThreadConnected(BluetoothSocket socket){

        myThreadConnected = new ThreadConnected(socket);
        myThreadConnected.start();
    }

    /*
    ThreadConnectBTdevice:
    Background Thread to handle BlueTooth connecting
    */
    private class ThreadConnectBTdevice extends Thread {

        private BluetoothSocket bluetoothSocket = null;
        private final BluetoothDevice bluetoothDevice;


        private ThreadConnectBTdevice(BluetoothDevice device) {
            bluetoothDevice = device;

            try {
                bluetoothSocket = device.createRfcommSocketToServiceRecord(myUUID);
                textStatus.setText("bluetoothSocket: \n" + bluetoothSocket);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        @Override
        public void run() {
            boolean success = false;
            try {
                bluetoothSocket.connect();
                success = true;
            } catch (IOException e) {
                e.printStackTrace();

                final String eMessage = e.getMessage();
                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        textStatus.setText("something wrong bluetoothSocket.connect(): \n" + eMessage);
                    }
                });

                try {
                    bluetoothSocket.close();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }

            if(success){
                //connect successful
                final String msgconnected = "connect successful:\n"
                        + "BluetoothSocket: " + bluetoothSocket + "\n"
                        + "BluetoothDevice: " + bluetoothDevice;

                runOnUiThread(new Runnable(){

                    @Override
                    public void run() {
                        textStatus.setText(msgconnected);

                        listViewPairedDevice.setVisibility(View.GONE);
                        inputPane.setVisibility(View.VISIBLE);
                    }});

                startThreadConnected(bluetoothSocket);
            }else{
                //fail
            }
        }

        public void cancel() {

            Toast.makeText(getApplicationContext(),
                    "close bluetoothSocket",
                    Toast.LENGTH_LONG).show();

            try {
                bluetoothSocket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }

    }

    /*
    ThreadConnected:
    Background Thread to handle Bluetooth data communication
    after connected
     */
    private class ThreadConnected extends Thread {
        private final BluetoothSocket connectedBluetoothSocket;
        private final InputStream connectedInputStream;
        private final OutputStream connectedOutputStream;

        public ThreadConnected(BluetoothSocket socket) {
            connectedBluetoothSocket = socket;
            InputStream in = null;
            OutputStream out = null;

            try {
                in = socket.getInputStream();
                out = socket.getOutputStream();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            connectedInputStream = in;
            connectedOutputStream = out;
        }

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

            while (true) {
                try {
                    bytes = connectedInputStream.read(buffer);
                    String strReceived = new String(buffer, 0, bytes);
                    final String msgReceived = String.valueOf(bytes) +
                            " bytes received:\n"
                            + strReceived;

                    runOnUiThread(new Runnable() {

                        @Override
                        public void run() {
                            textStatus.setText(msgReceived);
                        }});

                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();

                    final String msgConnectionLost = "Connection lost:\n"
                            + e.getMessage();
                    runOnUiThread(new Runnable(){

                        @Override
                        public void run() {
                            textStatus.setText(msgConnectionLost);
                        }});
                }
            }
        }

        public void write(byte[] buffer) {
            try {
                connectedOutputStream.write(buffer);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        public void cancel() {
            try {
                connectedBluetoothSocket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}


layout/activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/info"
        android:textStyle="bold|italic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/status"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <ListView
        android:id="@+id/pairedlist"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <LinearLayout
        android:id="@+id/inputpane"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:visibility="gone">

        <SeekBar
            android:id="@+id/analogOut"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:max="99"
            android:progress="0"/>

    </LinearLayout>

</LinearLayout>


uses-permission of "android.permission.BLUETOOTH" is needed in AndroidManifest.xml.

download filesDownload the files (Android Studio Format).


Arduino side:


Connection between Arduino and HC-06, refer to "Connect Arduino Due with HC-06 (Bluetooth Module)".

DueHC06_AT.ino
/*
Arduino Due + HC-06 (Bluetooth) - 
receive command to control LED (pin 13) brightness

Serial (Tx/Rx) communicate to PC via USB
Serial3 (Tx3/Rx3) connect to HC-06
HC-06 Rx - Due Tx3
HC-06 Tx - Due Rx3
HC-06 GND - Due GND
HC-06 VCC - Due 3.3V

*/
#define HC06 Serial3

int SYNC_BYTE = 0xAA;
int CMD_ANALOG = 1;

int rxState;
int rxLength;
int rxCmd;
const int rxState_0_idle = 0;
const int rxState_1_sync = 1;  //SYNC_BYTE received
const int rxState_2_cmd = 2;   //length received, waiting CMD
const int rxState_3_data = 3;  //CMD received, receiving data

int LED = 13;

void setup()
{
  pinMode(LED, OUTPUT);
  delay(1000);
  Serial.begin(9600);
  HC06.begin(9600);
  
  Serial.write("\nTest Start\n");
  rxState = rxState_0_idle;
}

void loop()
{
  while(HC06.available())
  {
    char rxData = (int)HC06.read();

    switch(rxState){
      case rxState_0_idle:
          if(rxData == SYNC_BYTE){
            rxState = rxState_1_sync;
            Serial.println("SYNC_BYTE received");
          }
          break;
      case rxState_1_sync:
          rxLength = rxData;
          Serial.println("Length: " + String(rxLength));
          rxLength--;
          rxState = rxState_2_cmd;
          
          break;

      case rxState_2_cmd:
          rxCmd = rxData;
          Serial.println("CMD: " + String(rxCmd));
          
          rxLength--;
          rxState = rxState_3_data;
          break;
          
      case rxState_3_data:
          Serial.println("data: " + String(rxData));
          //we have one command only
          if(rxCmd==CMD_ANALOG){
            int brightness = map(rxData, 0, 99, 0, 255);
            analogWrite(LED, brightness);
            Serial.println("brightness: " + String(brightness));
            HC06.println("brightness: " + String(brightness));
          }
        
          rxLength--;
          if(rxLength==0){
            rxState = rxState_0_idle;
          }

          break;
          
      default:
          rxState = rxState_0_idle;
    };
    
  }
}


You can also monitor the state on PC using Serial Monitor.


3 comments:

Anonymous said...

i am running this, it connects, but the light doent come out at all. i have changed the baud rate multiplying 9600 up to 249600, but it still doesnt produce anything. i am using Arduino MEGA 2560 , HC05-5v, and android 4.4.4. the pins seem similar

Anonymous said...

I'm also trying this on a Mega 2560 with HC05. The app runs without errors on my Samsung S7. The HC05 connects successfully to my phone and brings up the seek bar. However, the serial monitor shows nothing and the LED does nothing, no light at all. I tried pin 13 and A13, no result. I tested the LED beforehand so I know it works. Somehow, the app is not transmitting the seek bar data to the HC05 or the board does not know what to do with the data, because in the Arduino sketch, the switch case of rx_state is never changed, it's stuck on idle, maybe meaning the app is not sending the data properly or the HC05 isn't receiving the data properly. A little help? I'm new to Arduino, but experienced in Android.

Anonymous said...

In the Arduino sketch, at the end of the while loop, I output the rxState variable to serial monitor. The rxState never changes, it's always 0 (zero). The HC05 connects succesfully, app runs without errors, using Mega 2560, yet the rxState never changes. I suspect the Android app isn't sending the data or the HC05 isn't receiving the data. Not sure how to proceed. Any suggestions?