RdlP RdlP - 10 months ago 730
Android Question

Android Connect Bluetooth device automatically after pairing programmatically

In my app I need pairing bluetooth device and immediately connect with it.

I have the following function in order to pairing devices:

public boolean createBond(BluetoothDevice btDevice)
try {
Log.d("pairDevice()", "Start Pairing...");
Method m = btDevice.getClass().getMethod("createBond", (Class[]) null);
Boolean returnValue = (Boolean) m.invoke(btDevice, (Object[]) null);
Log.d("pairDevice()", "Pairing finished.");
return returnValue;

} catch (Exception e) {
Log.e("pairDevice()", e.getMessage());
return false;

And I use it as the following way:

Boolean isBonded = false;
try {
isBonded = createBond(bdDevice);
//Connect with device

And it show me the dialog to pairing devices and enter the pin.

The problem is that createBond functions always return true, and it doen's wait until I enter the pin and paired with device, so I don't use correctly:

isBonded = createBond(bdDevice);
if(isBonded) {...}

So the question is How can I paired with device and when it is paired connect to it?

P.D My code is based in the first answer of the following thread: Android Device Bluetooth pairing


I found the solution.

First I need a BroadcastReceiver like:

private BroadcastReceiver myReceiver = new BroadcastReceiver() {
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            if (device.getBondState() == BluetoothDevice.BOND_BONDED) {
                // CONNECT
        } else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            // Discover new device

And then I need register the receiver as follow:

IntentFilter intentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
context.registerReceiver(myReceiver, intentFilter);

In this way the receiver is listening for ACTION_FOUND (Discover new device) and ACTION_BOND_STATE_CHANGED (Device change its bond state), then I check if the new state is BOND_BOUNDED and if it is I connect with device.

Now when I call createBond Method (described in the question) and enter the pin, ACTION_BOND_STATE_CHANGED will fire and device.getBondState() == BluetoothDevice.BOND_BONDED will be True and it will connect.