Connecting Android with PC and displaying a message

Question

I am new to android. I am just trying to connect my Android device to PC and pass a string to PC using Bluetooth. I have no idea on how to do it. Android side I read about the Bluetooth API. Please suggest me some ways to do it. Thanks in advance.

Answer 1

For Android, my code is slightly different from yours:

BluetoothSocket socket = Device.createRfcommSocketToServiceRecord(device_UUID);
socket.connect();
DataOutputStream dos = new DataOutputStream(socket.getOutputStream());

dos.writeChar('x'); // for example

socket.close();

I used DataOutputStream to send data to PC. But surely this doesn't matter, just for your reference.

For PC,

LocalDevice localDevice = LocalDevice.getLocalDevice();

localDevice.setDiscoverable(DiscoveryAgent.GIAC); // Advertising the service

String url = "btspp://localhost:" + device_UUID + ";name=BlueToothServer";
StreamConnectionNotifier server = (StreamConnectionNotifier) Connector.open(url);

StreamConnection connection = server.acceptAndOpen(); // Wait until client connects
//=== At this point, two devices should be connected ===//
DataInputStream dis = connection.openDataInputStream();

char c;
while (true) {
    c = dis.readChar();
    if (c == 'x')
    break;
}

 connection.close();

I am not sure if the above codes still work today, as this was done 2 years ago. The BlueCove API may have changed a lot. But anyway, these codes work for me. Hope this may help you.

One more note is that, I had to uninstall the Toshiba Bluetooth Driver in my PC and reinstall the Microsoft one in order to make use of BlueCove. Otherwise, it won't work. (However, latest version of BlueCove may have already supported different drivers, please correct me if I said anything wrong.)

(Author: Victor Wong)

Answer 2

For clarification: on the PC side, you usually have a bluetooth device that comes with a virtual COM port. For testing purposes, you can use any terminal program (e.g. http://realterm.sourceforge.net/). When you start it on your virtual bluetooth serial port and connect your Android device, it will show the received data.