Develop Reference

Start the bonding process with a remote bluetooth device

I have managed to make an android device and scan and enlist all bluetooth devices in the area..I have the mac address of a remote device i just discovered in form of string and i want to start the bonding process with it.. i try BluetoothDevice object and then method createBond() but its not communicating with the remote device to pair..
Here is the code
class BluetoothM: AppCompatActivity{
// mac address of remote bluetooth device
string address;
//the discovered devices are listed in a ListView so i call a listview item click method to start pairing
private void Dlist_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
{
//the mac address has already been assigned in the OnReceive broadcast Receiver
if (e.Position == e.Id)
{
//Get the default adapter of the device
BluetoothAdapter adapt = BluetoothAdapter.DefaultAdapter;
//Get the remote device based on its MAC address
BluetoothDevice device = adapt.GetRemoteDevice(address);
//start the pairing process for the device
device.CreateBond();
}
}
}
//This class discovers bluetooth devices and pass MAC address to our string address for use in the listview click method
[BroadcastReceiver(Name = BluetoothDevice.ActionFound, Enabled = true)]
public class DeviceDiscovered : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
string ac = intent.Action; string name;
if (BluetoothDevice.ActionFound.Equals(ac))
{
BluetoothDevice device = (BluetoothDevice)intent.GetParcelableExtra(BluetoothDevice.ExtraDevice);
//add bluetooth name and address if they do not already exist
if (!MainActivity.avail.Contains(device.Name + "\n" + device.Address))
{
MainActivity.avail.Add(device.Name + "\n" + device.Address);
ArrayAdapter arrayAdapter1 = new ArrayAdapter(context, Android.Resource.Layout.SimpleListItem1, MainActivity.avail);
MainActivity.dlist.Adapter = arrayAdapter1;
//address assigned a value
MainActivity.address = device.Address; MainActivity.name = device.Name;
MainActivity.mydevice = device;
}
}
Toast.MakeText(context, "Received the intent", ToastLength.Short).Show();
}
The remote device is not receiving this communication and i don't know why, Thank You

Check you have BLUETOOTH_ADMIN permission in Manifest. Register for ACTION_BOND_STATE_CHANGED intents to be notified when the bonding process completes, and its result. Get the result of device.CreateBond(), it returns false on immediate error, true if bonding will begin.
https://developer.android.com/reference/android/bluetooth/BluetoothDevice#createBond()

Connect to bluetooth device via Hands Free Profile programatically on Android

We have a Bluegiga Bluetooth module that is set up to work as hands free device.
After initial pairing, I need my application to initiate connection to it via HFP programmatically. Can this be achieved in Android?

Using hidden api works for me!
// get default bluetooth adapter
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
// get bounded device on Android
Set<BluetoothDevice> devices = mAdapter.getBondedDevices();
if (devices.size() > 0) {
for (Iterator<BluetoothDevice> it = devices.iterator(); it.hasNext();) {
BluetoothDevice device = it.next();
// treat the device the default buletooth device you needed
mCurrentDevice = device;
// break;
}
} else {
return;
}
// another method to get headset(HFP) profile
mAdapter.getProfileProxy(mContext, new BluetoothProfile.ServiceListener() {
#Override
public void onServiceConnected(int profile, BluetoothProfile proxy) {
Log.e("log", "headset proxy connected");
try {
BluetoothHeadset mCurrentHeadset = (BluetoothHeadset) proxy;
// check whether or not current device hfp is connected or not, if not,
// try to connect the channel between phone and device using hidden api
if (mCurrentHeadset.getConnectionState(mCurrentDevice) != BluetoothHeadset.STATE_CONNECTED) {
Method connectMethod = mCurrentHeadset.getClass().getMethod("connect", mCurrentDevice.getClass());
connectMethod.setAccessible(true);
Boolean returnValue = (Boolean) connectMethod.invoke(proxy, mCurrentDevice);
Log.e("log", "headset proxy connected " + returnValue);
}
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public void onServiceDisconnected(int profile) {
Log.e(LogTag.TAG, "headset profile disconnected");
}
}, BluetoothA2dp.HEADSET);

Pairing to a CC2540 Bluetooth LE Device

I am trying to connect to a BLE devices based on CC2540 from TI (I have the keyfob from TI, and another device from connectblue OLP425) with my Motorola RAZR, the only succes I had so far is an app named Propagation on the market that I don't have access to the sources.
I tried to connect to the device with this code but the biggest thing I don't understand is the UUID,
I downloaded an app on a iPad 3 and I found a device has the following UUID
00000000-0000-0000-ff31-1a064f8c5966
private static final UUID SPP_UUID = UUID.fromString("00000000-0000-0000-ff31-1a064f8c5966");
BluetoothDevice bd =BluetoothAdapter.getDefaultAdapter().getBondedDevices().iterator().next();
//I only have I device paired that is the Bluetooth Low Energy Device so using the first Device returned by the iterator is fine.
try {
BluetoothSocket bs = bd.createRfcommSocketToServiceRecord(UUID);
bs.connect();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
All I get is a Service discovery failed in logcat
In almost all the example everyone is using
00000000-0000-1000-8000-00805f9b34fb
If I go further in the app it syas that the battery service is UUID 0x180f
I would just like to create an app the read the value of this service which is a simple decimal value
anyone has any succes pairing with a BLE device in the past?
thank you
Jonathan

I've been able to connect to my CC2540 with the Heart Rate Monitor.
I flashed the firmware using the CCDebugger and using 0000180d-0000-1000-8000-00805f9b34fbas the UUID i've been able to read a value.
Using the Motorola_BLE_profile sample app with some modifications.
primaryServices = mGattService.getGattPrimaryServices(device);
if (primaryServices == null) {
String message = "Connection failed !";
Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();
return;
}
for (i = 0; i < primaryServices.length; i++) {
Log.v(TAG, "primary service " + primaryServices[i]);
if (primaryServices[i].equalsIgnoreCase(hrmUUID)) {
try {
status = mGattService.connectGatt(device, hrmUUID, callback1);
if (status == true){
mDevice = device;
mLeState = CONNECTING;
BluetoothLeReceiver.isDevicePickerPending = false;
} else {
String message = "Connection failed !";
Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();
}
} catch (Exception e) {
Log.e(TAG,"Exception while calling gatt Connect");
}
return;
if (i == primaryServices.length) {
Log.v(TAG,"Primary Service not found");
String message = "Connection failed !";
Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();
}

Enabling USB tethering programmatically - there is an app that did it for 2.3

I've read many questions here on SO that ask how to enable USB tethering programmatically.
The answer is always the same, ordinary applications can't do it, only system apps.
Yet for 2.3 you could download an app in the market that would do it for you.
https://play.google.com/store/apps/details?id=org.tdtran.autousbtethering
On ICS (Android 4.0.3) it no longer works.
How did they do it for 2.3? Is it possible also for 4.0?

using the following code you can enable USB tethering. i didt test in 4.0.
public void switchOnTethering() {
Object obj = getSystemService(Context.CONNECTIVITY_SERVICE);
for (Method m : obj.getClass().getDeclaredMethods()) {
if (m.getName().equals("tether")) {
try {
m.invoke(obj, "usb0");
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

ICS and above: To execute the reflection method, the application would require the WRITE_SECURE_SETTINGS permission.
This is not available unless the phone is rooted.

since this is one of the most popular pages in the Google results for this topic I'd like to contribute my code which is checking the available interfaces. It does work on a Gingerbread phone I have, but not my Galaxy S3.
// DETECT INTERFACE NAME
Log.i("UsbTethering","Detecting tetherable usb interface.");
String[] available = null;
ConnectivityManager connMgr = (ConnectivityManager)connectivityServiceObject;
Method[] wmMethods = connMgr.getClass().getDeclaredMethods();
for(Method getMethod: wmMethods)
{
if(getMethod.getName().equals("getTetherableUsbRegexs"))
{
try
{
available = (String[]) getMethod.invoke(connMgr);
break;
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
// DETECT INTERFACE NAME
if(available.length > 0)
{
for(String interfaceName : available)
{
Log.i("UsbTethering", "Detected " + String.valueOf(available.length) + " tetherable usb interfaces.");
Log.i("UsbTethering", "Trying to " + desiredString + " UsbTethering on interface " + interfaceName + "...");
Integer returnCode = (Integer)method.invoke(connectivityServiceObject, interfaceName);
if(returnCode == 0)
{
Log.i("UsbTethering", "UsbTethering " + desiredString + "d.");
return true;
}
else
{
Log.w("UsbTethering", "Failed to " + desiredString + "Usb Tethering. ReturnCode of method " + method.getName() + ": " + String.valueOf(returnCode));
}
}
}

On Samsumg Galaxy Tab 2 10.1 the interface isn't called "usb0" but "rndis0". Maybe that's the same for Galaxy SII

The port "rndis0" is enabled dynamically not availble in the the Tetherable interfaces list.
It gets added when the user selects the USB Tethering option in the menu.
The function ConnectivityManager::setUsbTethering(bool) is called when the option is selected. And this function call is allowed only for System applications.

I know its an old thread but i hope this could help some other people in the future ,
That code worked for me in Android 4.4(with root privilege)
code:
the trick is to use reflection , the method which changes the usb tethring is called "setUsbTethering"
I wont write the entire class but here is what you need:
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
Method usbTethering = connectivityManager.getClass().getMethod('setUsbTethering')
int returnCode = (Integer)usbTethering.invoke(connectivityManager, true);
0 = success
you can print the entire class methods using the following code
private static void printClassMethod(#NonNull Class aClazz) {
Method[] wmMethods = aClazz.getDeclaredMethods();
for (Method method : wmMethods) {
Log.i('anytag', method.getName());
}
}
then call printClassMethod(ConnectivityManager.class)
More Over, you can go onto the class itself and check the methods and arguments needed.
to get things work:
you must set your app as System app,
Declare in manifest : android:sharedUserId="android.uid.system"
add writing secure permission<uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS"
Sign the apk using google certificate key(apk-with-system-privileges) and push it to /system/app
Mind, that usbTethering is turned on while USB is attached, so a nicer solution will be to register to both USB_STATE and USB_ATTACH and enable/disable it correspondingly in onReceive Method. (USB tethering is turned off automatically when USB is de-attached)

list connected bluetooth devices?

How can I list all connected bluetooth devices on android ?
thanks!

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);
}
};

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;
}

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

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());
}

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.

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

Please analyze this class online.
Here you will find how to discover all connected (paired) Bluetooth devices.

Well here are the steps:
First, you start intent to discover devices
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
Register a broadcast reciver for it:
registerReceiver(mReceiver, filter);
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.