I'm trying to check if my BluetoothDevice is connected to something.
If it is connected, obtain the data of the other device
I want to implement this function to my application since I need to monitor if the connection was lost or is still connected and add a visual indicator in case the connection changes.
Tried with this function but the toast shows nearby devices (not connected) constantly:
if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
String name = device.getName();
Toast.makeText(getApplicationContext(),name,Toast.LENGTH_SHORT).show();
}
AFAIK there is no way to view the state of the connection. Instead you monitor for changes in the state of the bluetooth connection. So you can register a receiver and then receive a broadcast when the device is disconnected.
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED);
this.registerReceiver(rec, filter);
private BroadcastReceiver rec = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_DISCONNECTED.equals(action)) {
// Bluetooth is now disconnected
}
}
Related
I'm working on an app that searches for discoverable devices and displays them as buttons.
When calling startDiscovery() I would say it works 30% of the time, based on the way I'm currently debugging it, with the BroadcastReceiver and ACTION_DISCOVERY_FINISHED.
I'm also using isDiscovering() to test if the startDiscovery() function is called but it returns false.
Is there a way to know if startDiscovery() is called successfully? And can you identify something in my code that would make it not fail?
Obs.: I have both BLUETOOTH AND BLUETOOTH_ADMIN permissions.
Here is my code:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scan);
mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
String Address;
// 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);
Address = device.getAddress();
System.out.println("Found Address: " + Address ); //DEBUG
//Do something with Address
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
System.out.println("Discovery finished");
}
}
};
// Register the BroadcastReceiver
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
MainActivity.mBluetoothAdapter.startDiscovery();
if (MainActivity.mBluetoothAdapter.isDiscovering()) {
System.out.println("Discovering..."); //DEBUG
}
}
Although I have a few discoverable devices available, none of them trigger onReceive() with ACTION_FOUND
UPDATE: I went to "Scan" under Bluetooth Settings while the app was running and I could not scan for new devices. I disabled/enabled Bluetooth and returned to the app and the problem was resolved. I don't know if that indicates that the adapter is busy or halted somehow.
I confirm this issue.
On some telephones you just need to disable/active BT. You can doit programatically with
mBluetoothAdapter.disable();
mBluetoothAdapter.enable();
On some telephones its not enough ( Samsung S5 ). To detect it, I use timer, and if on end of timeout the change of BT broadcast state (BluetoothAdapter.ACTION_DISCOVERY_STARTED or BluetoothAdapter.ACTION_DISCOVERY_FINISHED ) wasnt received => its sign that BT is not working. Actually I show dialog which propose to user reboot the telephone.
Is there a way I can ping for a Bluetooth device in Android? The bluetooth device is not connected or paired in Android, but I know beforehand the MAC address and the PIN of the device. What I'm trying to achieve is to ping a list of MAC addresses to see if any of the devices are in range.
Solved: What I did was query for the services available on the device (available UUIDs). If there's UUIDs received, then the device is in range.
So the steps were:
Register a broadcast received for the UUID action
String action = "android.bluetooth.device.action.UUID";
IntentFilter filter = new IntentFilter(action);
registerReceiver(mReceiver, filter);
Create a bluetooth device based on the remote address and fetch it's UUIDs
BluetoothDevice bd = bluetoothAdapter.getRemoteDevice(address);
bd.fetchUuidsWithSdp();
Create a broadcast receiver, which carries the device address, being able to tell me that that
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
//deviceExtra is our in range device
deviceExtra =
intent.getParcelableExtra("android.bluetooth.device.extra.DEVICE");
Parcelable[] uuidExtra =
intent.getParcelableArrayExtra("android.bluetooth.device.extra.UUID");
}}};
I'm trying to check if there is a bluetooth device paired when running my app.
In the main activity, I find bluetooth devices and pair to them. In the second activity, I must check if there is a device paired or not.
If a device is conected, it starts automatically sending data, but if there is no conexion, then it simply shows a toast.
I need to do this just when the second activity starts. I found this code, but I don't know how to make it to start when the activity is just created.
public void onCreate() {
//...
IntentFilter filter1 = new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED);
IntentFilter filter2 = new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED);
this.registerReceiver(mReceiver, filter1);
this.registerReceiver(mReceiver, filter2);
}
//The BroadcastReceiver that listens for bluetooth broadcasts
private final BroadcastReceiver BTReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
//Do something if connected
}
else if (BluetoothDevice.ACTION_ACL_DISCONNECTED.equals(action)) {
//Do something if disconnected
}
}
};
Here is a complete description of the problem, with the correct answer to solve it:
Action to know if there is any bluetooth paired device
I want to listen for connection/disconnection with a number of specific bluetooth devices whose MAC addresses I know, but which are not necessarily paired (I don't want to mess with the user's list of paired devices and vice versa). I'm only interested in discovering their presence, not communicating with them.
This works very well with my code below! But my problem is that I cannot find out which specific device is connecting/disconnecting, only that it happens to someone of them. How can I find out which one the action concerns?
First I instantiate objects for my two specific physical bluetooth devices and add them to my intent filter:
BluetoothDevice myPinkHeadset = mBluetoothAdapter.getRemoteDevice("18:17:0C:EB:9C:81");
BluetoothDevice myPcBluetoothDongle = mBluetoothAdapter.getRemoteDevice("5A:7A:CC:4B:C5:08");
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(myPinkHeadset.ACTION_ACL_CONNECTED);
intentFilter.addAction(myPinkHeadset.ACTION_ACL_DISCONNECTED);
intentFilter.addAction(myPcBluetoothDongle.ACTION_ACL_CONNECTED);
intentFilter.addAction(myPcBluetoothDongle.ACTION_ACL_DISCONNECTED);
Then I listen for broadcasts about them:
final BroadcastReceiver intentReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Now I want to find out which one has been connected and/or disconnected, and I don't see how I can do that.
Either 1) I use "BluetoothDevice" directly. It reacts to the broadcast alright, but it doesn't tell me which of the two physical devices the action concerns. Is their a way to find out? Bluetooth.getName() is not allowed because it's not a static class.
if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
}
or 2) I listen for both actions for both devices.
if (myPinkHeadset .ACTION_ACL_CONNECTED.equals(action)) {
Log.v(TAG, "Connected to myPinkHeadset ");
}
else if (myPinkHeadset .ACTION_ACL_DISCONNECTED.equals(action)) {
Log.v(TAG, "Disconnected from myPinkHeadset ");
}
else if (myPcBluetoothDongle .ACTION_ACL_CONNECTED.equals(action)) {
Log.v(TAG, "Connected to myPcBluetoothDongle ");
}
else if (myPcBluetoothDongle .ACTION_ACL_DISCONNECTED.equals(action)) {
Log.v(TAG, "Disconnected from myPcBluetoothDongle ");
But then it logs that it connects with myPinkHeadset even if it is myPvBluetoothDongle I activate physically. It always goes for the one which comes first of the if tests. It cares only about the action itself, not about which object it concerns.
I saw that EXTRA_DEVICE is "Used as a Parcelable BluetoothDevice extra field in every intent broadcast by this class." But it only returns null to me:
String extra = intent.getStringExtra(BluetoothDevice.EXTRA_DEVICE);
This gives the device connected to:
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
As a newbie, I misunderstood the parcelable concept. EXTRA_DEVICE is a String, but it's just a tag for the object. So there's no need to register or listen to individual instances of BluetoothDevice. When an action is broadcasted, the intent will tell which physical device caused it. (Can I +1 myself for this :-D)
intentFilter.addAction(myPinkHeadset.ACTION_ACL_CONNECTED);
intentFilter.addAction(myPcBluetoothDongle.ACTION_ACL_CONNECTED);
and
intentFilter.addAction(myPinkHeadset.ACTION_ACL_DISCONNECTED);
intentFilter.addAction(myPcBluetoothDongle.ACTION_ACL_DISCONNECTED);
are the same value. It's static value.
BluetoothDevice.ACTION_ACL_CONNECTED and BluetoothDeviceACTION_ACL_DISCONNECTED
private void register() {
context.registerReceiver(bluetoothBroadCast, new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED));
context.registerReceiver(bluetoothBroadCast, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED ));
}
private final BroadcastReceiver bluetoothBroadCast = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
switch (action) {
case BluetoothDevice.ACTION_ACL_CONNECTED: {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if(device.getAddress().equals(myPinkHeadset.getAddress)) {
//Do what you want
}
break;
}
case BluetoothDevice.ACTION_ACL_DISCONNECTED: {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
break;
}
}
}
};
I hope this can help you
In android how can my Activity will get to know if a Bluetooth A2DP device is connected to my device.
Is there any broadcast receiver for that?
How to write this broadcast receiver?
Starting from API 11 (Android 3.0) you can use BluetoothAdapter to discover devices connected to a specific bluetooth profile. I used the code below to discover a device by its name:
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothProfile.ServiceListener mProfileListener = new BluetoothProfile.ServiceListener() {
public void onServiceConnected(int profile, BluetoothProfile proxy) {
if (profile == BluetoothProfile.A2DP) {
boolean deviceConnected = false;
BluetoothA2dp btA2dp = (BluetoothA2dp) proxy;
List<BluetoothDevice> a2dpConnectedDevices = btA2dp.getConnectedDevices();
if (a2dpConnectedDevices.size() != 0) {
for (BluetoothDevice device : a2dpConnectedDevices) {
if (device.getName().contains("DEVICE_NAME")) {
deviceConnected = true;
}
}
}
if (!deviceConnected) {
Toast.makeText(getActivity(), "DEVICE NOT CONNECTED", Toast.LENGTH_SHORT).show();
}
mBluetoothAdapter.closeProfileProxy(BluetoothProfile.A2DP, btA2dp);
}
}
public void onServiceDisconnected(int profile) {
// TODO
}
};
mBluetoothAdapter.getProfileProxy(context, mProfileListener, BluetoothProfile.A2DP);
You can do that for every bluetooth profile. Take a look at Working with profiles in Android's guide.
However, as written in other answers, you can register a BroadcastReceiver to listen to connection events (like when you're working on android < 3.0).
You cannot get the list of connected devices by calling any API.
You need instead to listen to the intents ACTION_ACL_CONNECTED, ACTION_ACL_DISCONNECTED that notifies about devices being connected or disconnected.
No way to get the initial list of connected devices.
I had this problem in my app and the way I handle it (didn't find better...) is to bounce off/on the Bluetooth at application start to be sure to start with an empty list of connected devices, and then listen to the above intents.
muslidrikk's answer is broadly correct; however you can alternatively use fetchUUIDsWithSDP() and see what you get back... it's a bit of a hack though -- you'd have to know what UUIDs (capabilities) you could expect from the device, if it were turned on. And that might be difficult to guarantee.
For BluetoothHeadset specifically, you can call getConnectedDevices() to get connected devices for this specific profile.
Reference: http://developer.android.com/reference/android/bluetooth/BluetoothHeadset.html
Other cases you need to register a receiver for that.
In your activity, define broadcast receiver...
// Create a BroadcastReceiver for ACTION_FOUND
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
mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
};
// Register the BroadcastReceiver
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy