通过蓝牙连续发送字符串消息

1 回答

• 0

  好的，我想出了如何做到这一点 . 我使用Service来连接蓝牙设备而不是AsyncTask . 我使用了两个处理程序 . 现在一切正常 . 我可以每500ms发送一次String消息，也可以从OBD2接口获得响应 . 以下是服务类的代码 . 我使用BroadcastReceiver从Service接收数据到我的UI .

  public class BTConnect extends Service {
  
      private BluetoothAdapter btAdapter;
      private String adress;
      private static UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
      private BluetoothSocket mmSocket;
      private boolean isBTConnected = false;
      private ConnectedThread mConncetedThread;
      Handler h;
      Handler HandlerDelay = new Handler();
      final int handlerState = 0;
      public StringBuilder recDataString = new StringBuilder();
      private Timer mTimer;
      final static String MY_ACTION = "MY_ACTION";
  
  
      public BTConnect() {
      }
  
      @Override
      public IBinder onBind(Intent intent) {
          // TODO: Return the communication channel to the service.
          throw new UnsupportedOperationException("Not yet implemented");
      }
  
  
      @Override
      public void onCreate() {
          super.onCreate();
  
          if(mTimer != null) {
  
              mTimer.cancel();
  
          } else {
  
              mTimer = new Timer();
          }
  
          mTimer.scheduleAtFixedRate(new TimerDisplay(), 0, 500);
      }
  
      @Override
      public int onStartCommand(Intent intent, int flags, int startId) {
  
          String adressMac = intent.getStringExtra("MAC_ADRESS");
  
          // Trzeba sie połączyć
  
          h = new MyHandler();
  
          tryToConnect(adressMac);
  
          return START_NOT_STICKY;
      }
  
  
  
      private void tryToConnect(String address) {
  
          try {
              if (mmSocket == null || !isBTConnected) {
  
                  btAdapter = BluetoothAdapter.getDefaultAdapter();
  
                  BluetoothDevice device = btAdapter.getRemoteDevice(address);
  
                  mmSocket = device.createInsecureRfcommSocketToServiceRecord(myUUID);
  
                  BluetoothAdapter.getDefaultAdapter().cancelDiscovery();
  
                  mmSocket.connect();
  
                  isBTConnected = true;
  
                  mConncetedThread = new ConnectedThread(mmSocket);
                  mConncetedThread.start();
  
  
              }
  
  
          } catch (IOException e) {
  
              Log.e("Error", String.valueOf(e));
  
          }
  
              if (isBTConnected) {
  
                  Log.d("Status", "Connected");
                  Toast.makeText(getBaseContext(), "Connected", Toast.LENGTH_LONG);
  
              }
  
      }
  
  
      private class ConnectedThread extends Thread {
  
          private final InputStream mmInStream;
          private final OutputStream mmOutStream;
  
  
          public ConnectedThread(BluetoothSocket  socket) {
  
              mmSocket = socket;
  
              InputStream tmpIn = null;
              OutputStream tmpOut = null;
  
              try {
                  tmpIn = socket.getInputStream();
                  tmpOut = socket.getOutputStream();
  
              } catch (IOException e) {
  
                  e.printStackTrace();
              }
  
              mmInStream = tmpIn;
              mmOutStream = tmpOut;
  
          }
  
          @Override
          public void run() {
              super.run();
  
              byte[] mmBuffer = new byte[1024];
  
              int mmBytes;
  
  
              //Start Listening
  
              while(true) {
  
                  try {
                      mmBytes = mmInStream.read(mmBuffer);
  
                      Message readMsg = h.obtainMessage(handlerState, mmBytes, -1, mmBuffer);
                      readMsg.sendToTarget();
  
  
                  } catch (IOException e){
  
                      e.printStackTrace();
                      Toast.makeText(getBaseContext(), "Input stream was disconnected", Toast.LENGTH_LONG).show();
                      break;
  
                  }
  
              }
          }
  
          public void write(){
  
              try {
                  mmSocket.getOutputStream().write("010C\r".getBytes());
              } catch (IOException e) {
                  Log.e("Error", String.valueOf(e));
              }
          }
      }
  
  
      private class MyHandler extends Handler {
  
          @Override
          public void handleMessage(Message msg) {
              super.handleMessage(msg);
  
              if (msg.what == handlerState) {
  
                  Intent sendIntent = new Intent();
  
                  byte[] rBuff = (byte[]) msg.obj; // recived message (bytes)
  
                  String readMessage = new String(rBuff, 0, msg.arg1); // convert that message to string
  
                  recDataString.append(readMessage);
  
                  Log.d("Tab", String.valueOf(recDataString));
  
                  int startOfIndex = recDataString.indexOf("41 0C");
                  int stopIndex = recDataString.indexOf(">");
  
                  if (stopIndex > 0) {
  
                      Log.d("RedVal", String.valueOf(recDataString));
                      String msg1 = String.valueOf(recDataString);
  
                      sendIntent.putExtra("SEND_MESSAGE", msg1);
                      sendIntent.setAction(MY_ACTION);
                      sendBroadcast(sendIntent);
  
  
                      recDataString.delete(0, recDataString.length());
  
  
                  } else if(recDataString.length() > 33) {
  
  
  
                      String msg1 = String.valueOf(recDataString.substring(recDataString.length()-26, recDataString.length()));
                      sendIntent.putExtra("SEND_MESSAGE", msg1);
                      sendIntent.setAction(MY_ACTION);
                      sendBroadcast(sendIntent);
                      recDataString.delete(0, recDataString.length());
                  }
  
  
  
  
              }
  
          }
      }
  
      class TimerDisplay extends TimerTask {
  
          @Override
          public void run() {
              HandlerDelay.postDelayed(new Runnable() {
                  @Override
                  public void run() {
                      mConncetedThread.write();
                  }
              },500);
          }
      }
  
  
  
  
  }
  

  回复于 2024-04-28T23:54:09+08:00