list connected bluetooth devices?

Question

How can I list all connected bluetooth devices on android ?

thanks!

Answer 1

public void checkConnected()
{
  // true == headset connected && connected headset is support hands free
  int state = BluetoothAdapter.getDefaultAdapter().getProfileConnectionState(BluetoothProfile.HEADSET);
  if (state != BluetoothProfile.STATE_CONNECTED)
    return;

  try
  {
    BluetoothAdapter.getDefaultAdapter().getProfileProxy(_context, serviceListener, BluetoothProfile.HEADSET);
  }
  catch (Exception e)
  {
    e.printStackTrace();
  }
}

private ServiceListener serviceListener = new ServiceListener()
{
  @Override
  public void onServiceDisconnected(int profile)
  {

  }

  @Override
  public void onServiceConnected(int profile, BluetoothProfile proxy)
  {
    for (BluetoothDevice device : proxy.getConnectedDevices())
    {
      Log.i("onServiceConnected", "|" + device.getName() + " | " + device.getAddress() + " | " + proxy.getConnectionState(device) + "(connected = "
          + BluetoothProfile.STATE_CONNECTED + ")");
    }

    BluetoothAdapter.getDefaultAdapter().closeProfileProxy(profile, proxy);
  }
};

Answer 2

As of API 14 (Ice Cream), Android has a some new BluetoothAdapter methods including:

public int getProfileConnectionState (int profile)

where profile is one of HEALTH, HEADSET, A2DP

Check response, if it's not STATE_DISCONNECTED you know you have a live connection.

Here is code example that will work on any API device:

BluetoothAdapter mAdapter;

/**
 * Check if a headset type device is currently connected. 
 * 
 * Always returns false prior to API 14
 * 
 * @return true if connected
 */
public boolean isVoiceConnected() {
    boolean retval = false;
    try {
        Method method = mAdapter.getClass().getMethod("getProfileConnectionState", int.class);
        // retval = mAdapter.getProfileConnectionState(android.bluetooth.BluetoothProfile.HEADSET) != android.bluetooth.BluetoothProfile.STATE_DISCONNECTED;
        retval = (Integer)method.invoke(mAdapter, 1) != 0;
    } catch (Exception exc) {
        // nothing to do
    }
    return retval;
}

Answer 3

• First you need to retrieve the BluetoothAdapter :

final BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter();

• Second you need to make sure Bluetooth is available and turned on :

if (btAdapter != null && btAdapter.isEnabled()) // null means no Bluetooth!

If the Bluetooth is not turned out you can either use btAdapter.enable() which is not recommended in the documentation or ask the user to do it : Programmatically enabling bluetooth on Android

• Third you need to define an array of states (to filter out unconnected devices):

final int[] states = new int[] {BluetoothProfile.STATE_CONNECTED, BluetoothProfile.STATE_CONNECTING};

• Fourth, you create a BluetoothProfile.ServiceListener which contains two callbacks triggered when a service is connected and disconnected :

   final BluetoothProfile.ServiceListener listener = new BluetoothProfile.ServiceListener() { @Override public void onServiceConnected(int profile, BluetoothProfile proxy) { } @Override public void onServiceDisconnected(int profile) { } };

---

Now since you have to repeat the querying process for all available Bluetooth Profiles in the Android SDK ( A2Dp, GATT, GATT_SERVER, Handset, Health, SAP ) you should proceed as follow :

In onServiceConnected , place a condition that check what is the current profile so that we add the found devices into the correct collection and we use : proxy.getDevicesMatchingConnectionStates(states) to filter out unconnected devices:

switch (profile) {
    case BluetoothProfile.A2DP:
        ad2dpDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
    case BluetoothProfile.GATT: // NOTE ! Requires SDK 18 !
        gattDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
    case BluetoothProfile.GATT_SERVER: // NOTE ! Requires SDK 18 !
        gattServerDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
    case BluetoothProfile.HEADSET: 
        headsetDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
    case BluetoothProfile.HEALTH: // NOTE ! Requires SDK 14 !
        healthDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
    case BluetoothProfile.SAP: // NOTE ! Requires SDK 23 !
        sapDevices.addAll(proxy.getDevicesMatchingConnectionStates(states));
        break;
}

And finally, the last thing to do is start the querying process :

btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.A2DP);
btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.GATT); // NOTE ! Requires SDK 18 !
btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.GATT_SERVER); // NOTE ! Requires SDK 18 !
btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.HEADSET);
btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.HEALTH); // NOTE ! Requires SDK 14 !
btAdapter.getProfileProxy(yourContext, listener, BluetoothProfile.SAP); // NOTE ! Requires SDK 23 !

source: https://stackoverflow.com/a/34790442/2715054

Answer 4

So you get the list of paired devices.

 BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter();
    Set<BluetoothDevice> pairedDevicesList = btAdapter.getBondedDevices();


    for (BluetoothDevice pairedDevice : pairedDevicesList) {
    Log.d("BT", "pairedDevice.getName(): " + pairedDevice.getName());
    Log.d("BT", "pairedDevice.getAddress(): " + pairedDevice.getAddress());

    saveValuePreference(getApplicationContext(), pairedDevice.getName(), pairedDevice.getAddress());

}

Answer 5

I found a solution and it works on android 10

Kotlin

private val serviceListener: ServiceListener = object : ServiceListener {
    var name: String? = null
    var address: String? = null
    var threadName: String? = null
    override fun onServiceDisconnected(profile: Int) {}
    override fun onServiceConnected(profile: Int, proxy: BluetoothProfile) {
        for (device in proxy.connectedDevices) {
            name = device.name
            address = device.address
            threadName = Thread.currentThread().name
            Toast.makeText(
                this@MainActivity,
                "$name $address$threadName",
                Toast.LENGTH_SHORT
            ).show()
            Log.i(
                "onServiceConnected",
                "|" + device.name + " | " + device.address + " | " + proxy.getConnectionState(
                    device
                ) + "(connected = "
                        + BluetoothProfile.STATE_CONNECTED + ")"
            )
        }
        BluetoothAdapter.getDefaultAdapter().closeProfileProxy(profile, proxy)
    }
}

Call this method in main thread

BluetoothAdapter.getDefaultAdapter()
            .getProfileProxy(this, serviceListener, BluetoothProfile.HEADSET)

Java

original code

Answer 6

Android system doesn't let you query for all "currently" connected devices. It however, you can query for paired devices. You will need to use a broadcast receiver to listen to ACTION_ACL_{CONNECTED|DISCONNECTED} events along with STATE_BONDED event to update your application states to track what's currently connected.

Answer 7

Please analyze this class online.

Here you will find how to discover all connected (paired) Bluetooth devices.

Answer 8

Well here are the steps:

1. First, you start intent to discover devices

   IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);

2. Register a broadcast reciver for it:

   registerReceiver(mReceiver, filter);

3. On the definition of mReceiver:

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String action = intent.getAction(); // When discovery finds a device if (BluetoothDevice.ACTION_FOUND.equals(action)) { // Get the BluetoothDevice object from the Intent BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // Add the name and address to an array adapter to show in a ListView arrayadapter.add(device.getName())//arrayadapter is of type ArrayAdapter<String> lv.setAdapter(arrayadapter); //lv is the list view arrayadapter.notifyDataSetChanged(); } }

and the list will be automatically populated on new device discovery.