Android中鏈接藍牙設備時遇到createRfcommSocketToServiceRecord的UUID問題和BluetoothSocket的connect失敗

【問題】

折騰：

【記錄】編寫Android中的藍牙模塊驅動和底層HART設備

期間，參考：

Bluetooth | Android Developers – ManagingAConnection

參考「Connecting as a client」中的：

tmp = device.createRfcommSocketToServiceRecord(MY_UUID);

遇到UUID不懂的問題。

而後隨便去

http://www.guidgenerator.com/online-guid-generator.aspx

弄了個UUID：

e214d9ae-c3ba-4e25-abb5-299041353bc3

結果運行到：

            try {
                // Connect the device through the socket. This will block
                // until it succeeds or throws an exception
                mmSocket.connect();
            } catch (IOException connectException) {
                // Unable to connect; close the socket and get out
                try {
                    mmSocket.close();
                } catch (IOException closeException) { }
                return;
            }

中的：

mmSocket.connect(); 

時就拋異常了。

即：

遇到createRfcommSocketToServiceRecord的UUID不懂，以及BluetoothSocket的connect失敗。

 

【解決過程】

1.參考：

android – Why can’t HTC Droid running OTA 2.1 communicate with RFCOMM? – Stack Overflow

去試試：

Method m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
mBTSocket = (BluetoothSocket) m.invoke(device, 1);

結果看着就不太對啊。。就不繼續試了。

2.參考：

Need Bluetooth UUID clarification – Google Groups

去試試：

00001101-0000-100­0-8000-00805F9B34FB

結果直接掛掉。

3.再去試試：

00000003-0000-100­0-8000-00805F9B34FB

也會掛掉。

4.後來再去搜：

android bluetooth connect fail

而後去參考：

android bluetooth can’t connect – Stack Overflow

和：

The Missing Manual: Android Bluetooth RFCOMM « Wires Are Obsolete

去試試，用代碼：

 // Create a BroadcastReceiver for ACTION_FOUND
 private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
     public void onReceive(Context context, Intent intent) {
//	 BluetoothDevice deviceExtra = intent.getParcelableExtra("android.bluetooth.device.extra.DEVICE");
//	 Parcelable[] uuidExtra = intent.getParcelableArrayExtra("android.bluetooth.device.extra.UUID");

         String action = intent.getAction();
         // When discovery finds a device
         if (BluetoothDevice.ACTION_FOUND.equals(action)) {
             // Get the BluetoothDevice object from the Intent
             BluetoothDevice btDev = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
             Parcelable[] btDevUuid = intent.getParcelableArrayExtra(BluetoothDevice.EXTRA_UUID);

調試獲得的btDevUuid都是null的。

5.換用：

         if (BluetoothDevice.ACTION_FOUND.equals(action)) {
             // Get the BluetoothDevice object from the Intent
             BluetoothDevice btDev = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
             //Parcelable[] btDevUuid = intent.getParcelableArrayExtra(BluetoothDevice.EXTRA_UUID);
             UUID btDevUuid = intent.getParcelableExtra(BluetoothDevice.EXTRA_UUID);

仍是不行。

6.參考：

Issue 15919 – android – Bluetooth connect fails under 2.3.3 for SPP devices using secure comms

中提到的：

BluetoothDevice | Android Developers

中提示的：

Hint: If you are connecting to a Bluetooth serial board then try using the well-known SPP UUID 00001101-0000-1000-8000-00805F9B34FB. However if you are connecting to an Android peer then please generate your own unique UUID.

因此再去試試這個UUID：

00001101-0000-1000-8000-00805F9B34FB

最終是能夠了：

對應的相關代碼爲：

 private String mactekHartModemName;
 private UUID mactekHartModemUuid;
    
 //void afterFoundBtHartModem(BluetoothDevice btDev, Parcelable[] btDevUuid){
 void afterFoundBtHartModem(BluetoothDevice btDev, UUID btDevUuid){
  if(null != btDevUuid){
      
  }
  
     //mactekHartModemName = btDev.getName(); //"MACTekViator75FE"
     //mactekHartModemUuid = UUID.fromString(mactekHartModemName);
  
  String uuidValue;
  //http://www.guidgenerator.com/online-guid-generator.aspx
  //uuidValue = "e214d9ae-c3ba-4e25-abb5-299041353bc3";
  
  //https://groups.google.com/forum/#!topic/android-developers/vyTEJOXELos
  //uuidValue = "00001101-0000-100­0-8000-00805F9B34FB";
  //uuidValue = "00000003-0000-100­0-8000-00805F9B34FB";
  uuidValue = "00001101-0000-1000-8000-00805F9B34FB";

  mactekHartModemUuid = UUID.fromString(uuidValue);

     ConnectThread connectBtThread = new ConnectThread(btDev);
     connectBtThread.start();
 }

    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
     
        public ConnectThread(BluetoothDevice device) {
            // Use a temporary object that is later assigned to mmSocket,
            // because mmSocket is final
            BluetoothSocket tmp = null;
            mmDevice = device;
     
            // Get a BluetoothSocket to connect with the given BluetoothDevice
            try {
                // MY_UUID is the app's UUID string, also used by the server code
                tmp = device.createRfcommSocketToServiceRecord(mactekHartModemUuid);//00001101-0000-1000-8000-00805F9B34FB

            } catch (IOException e) { }
            mmSocket = tmp;
        }
     
        public void run() {
            // Cancel discovery because it will slow down the connection
            mBluetoothAdapter.cancelDiscovery();
     
            try {
                // Connect the device through the socket. This will block
                // until it succeeds or throws an exception
                mmSocket.connect();
            } catch (IOException connectException) {
                // Unable to connect; close the socket and get out
                try {
                    mmSocket.close();
                } catch (IOException closeException) { }
                return;
            }
     
            // Do work to manage the connection (in a separate thread)
            manageConnectedSocket(mmSocket);
        }
     
        /** Will cancel an in-progress connection, and close the socket */
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) { }
        }
    }

 

【總結】

此處，必須使用Android的SSP（協議棧默認）的UUID：

00001101-0000-1000-8000-00805F9B34FB

才能正常和外部的，也是SSP串口的藍牙設備去鏈接。