Bluetooth connection throwing error

Question

I have written a normal code to connect to a standard bluetooth device ( a wocket). What I am doing is connecting to the wocket (which is just a piece of bluetooth chip), as a client. I am using a random UUID to connect to the wocket. But the connect method is throwing a IO Exception telling me that it is not able to connect to the Bluetooth device. The code that I am using is from Android Developers forum here : http://developer.android.com/guide/topics/connectivity/bluetooth.html

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(MY_UUID);
    } 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();
        **This call is throwing and IOException saying:
        java.io.IOException Discovery Failed.

**

    } 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) { }
}

}

What could be the reason the wocket is throwing an IOException. I don't think it makes any sense to connect to it being a server as for a server you establish a UUID and then you expect the client to have the same UUID, which is not possible in my case because I cannot program the wocket.

I am using an HTC one x with Android 4.0 as the testing device.

Thank you in advance.

nam_ph nam_ph · Accepted Answer · 2012-09-12T03:42:06

inspite of using a Random UUID use the serial port profile's UUID i.e. "00001101-0000-1000-8000-00805f9b34fb" because the random UUID you are using may not be supported by the wocket. when you do

createRfcommSocketToServiceRecord(MY_UUID);

it does a service discovery on the device you are connecting to , and see whether the UUID you have given is there in the device or not , if present it connects to the device.

Bluetooth connection throwing error

1 Answers