Develop Reference

BLE connected with Lollipop but not connected with Nougat

I'm new in android develop and I'm developing an app that transmit/receive data to a BLE module via Uart service.
With smartphone android 5.x.x the app works fine, it connects with the hardware and receive/transmit data.
With smartphone android 7.x.x the app doesn't connects.
Below you can see a snippet of MainActivity.java:
private final BroadcastReceiver UARTStatusChangeReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
final Intent mIntent = intent;
//*********************//
if (action.equals(UartService.ACTION_GATT_CONNECTED)) {
runOnUiThread(new Runnable() {
public void run() {
Log.d(TAG, "HW_CONNECT_MSG");
DisconnectButton.setEnabled(true);
DeviceInfo.setText("Device Information:");
DeviceName.setText(mDevice.getName() + " - Connected");
mState = UART_PROFILE_CONNECTED;
isConnected = true;
if(isConnected) {
//Serial protocol to send command on MCU
Connectcmd[0] = (byte) STX;
Connectcmd[1] = (byte) 0x02;
Connectcmd[2] = (byte) 0x43; // 'C';
Connectcmd[3] = (byte) 0x54; // 'T'
Connectcmd[4] = (byte) ETX;
try {
//send data to UART service
SendData(Connectcmd);
sleep(500); // wait 500ms to send data
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
new Handler().postDelayed(mUpdateTimeTask, 2000);
}
else
{
isConnected = false;
}
}
});
}
It's seem that when SendData, the GATT operation is not yet finished. Smartphone show the message "Device doesn't support UART over BLE. Disconnecting..." due to action.equals(UartService.DEVICE_DOES_NOT_SUPPORT_BLE_UART).
If I delete the if(isConnected)...else... statement also smartphone with android 7.x.x will connects.
My question is what's happen and how can I resolve this issue?
My goal is to send a command to hardware via BLE so when the mcu is connected, a buzzer make a sound.
Thanks for help….
EDIT
Below you can find the whole MainActivity:
public class MainActivity extends Activity implements RadioGroup.OnCheckedChangeListener {
public static final String TAG = "DEBUG ";
public static final String DEV_NAME_FILTER = "";
private static final int REQUEST_SELECT_DEVICE = 1;
private static final int REQUEST_ENABLE_BT = 2;
private static final int UART_PROFILE_READY = 10;
private static final int UART_PROFILE_CONNECTED = 20;
public static final int UART_PROFILE_DISCONNECTED = 21;
private static final int STATE_OFF = 10;
private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
TextView mRemoteRssiVal;
RadioGroup mRg;
private int mState = UART_PROFILE_DISCONNECTED;
private static UartService mService = null;
private static BluetoothDevice mDevice = null;
private BluetoothAdapter mBtAdapter = null;
private ListView messageListView;
private ArrayAdapter<String> listAdapter;
private Button SelectButton, DisconnectButton;
private EditText edtMessage;
private static Context context;
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
private static TextView DeviceInfo;
private static TextView DeviceName;
private static TextView Manufacturer;
public static boolean isConnected;
public static boolean isSetting;
public static boolean isReading;
public static boolean isManual;
public static boolean isFunctional;
public static boolean isBootloader;
public static byte[] SettingValues;
public static byte[] ReadingValues;
public static byte[] ManualValues;
public static byte[] FunctionalValues;
private static byte[] Connectcmd = new byte[5];
public static int STX = 0x3E; // '>'
public static int ETX = 0x23; // '#'
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DeviceInfo = (TextView) findViewById(R.id.deviceInfo);
DeviceName = (TextView) findViewById(R.id.deviceName);
Manufacturer= (TextView) findViewById(R.id.manufacturer);
isConnected = false;
isSetting = false;
isReading = false;
isManual = false;
isFunctional = false;
isBootloader = false;
context = this;
//Enable location
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// Android M Permission check
if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("This app needs location access");
builder.setMessage("Please grant location access so this app can detect beacons.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
#TargetApi(Build.VERSION_CODES.M)
public void onDismiss(DialogInterface dialog) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
}
});
builder.show();
}
}
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBtAdapter == null) {
Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show();
finish();
return;
}
SelectButton = (Button) findViewById(R.id.button);
DisconnectButton = (Button) findViewById(R.id.disconnect);
DisconnectButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Serial protocol to send command on MCU
Connectcmd[0] = (byte) STX;
Connectcmd[1] = (byte) 0x02;
Connectcmd[2] = (byte) 0x44; // 'D';
Connectcmd[3] = (byte) 0x43; // 'C'
Connectcmd[4] = (byte) ETX;
try {
//send data to Banner service
SendData(Connectcmd);
sleep(500); // Wait 500ms to send data
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
MainActivity.disconnected();
setContentView(R.layout.activity_main);
finish();
} catch (Exception e) {
Log.e(TAG, "Disconnect error");
}
}
});
// Handle Select device button
SelectButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!mBtAdapter.isEnabled()) {
Log.i(TAG, "onClick - BT not enabled yet");
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
} else {
if (SelectButton.getText().equals("SELECT CELU")) {
//Connect button pressed, open DeviceListActivity class, with popup windows that scan for devices
Log.i(TAG, "Push button CONNECT");
Intent newIntent = new Intent(context, DeviceListActivity.class);
((Activity) context).startActivityForResult(newIntent, MainActivity.REQUEST_SELECT_DEVICE);
} else {
//Disconnect button pressed
disconnected();
}
}
}
});
// Set initial UI state
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}
//UART service connected/disconnected
private ServiceConnection mServiceConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder rawBinder) {
mService = ((UartService.LocalBinder) rawBinder).getService();
Log.d(TAG, "onServiceConnected mService= " + mService);
if (!mService.initialize()) {
Log.e(TAG, "Unable to initialize Bluetooth");
finish();
}
}
public void onServiceDisconnected(ComponentName classname) {
//// mService.disconnect(mDevice);
mService = null;
}
};
private Handler mHandler = new Handler() {
#Override
//Handler events that received from UART service
public void handleMessage(Message msg) {
}
};
private final BroadcastReceiver UARTStatusChangeReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
final Intent mIntent = intent;
//*********************//
if (action.equals(UartService.ACTION_GATT_CONNECTED)) {
runOnUiThread(new Runnable() {
public void run() {
String currentDateTimeString = DateFormat.getTimeInstance().format(new Date());
Log.d(TAG, "CELU_CONNECT_MSG");
//btnConnectDisconnect.setText("Disconnect");
//edtMessage.setEnabled(true);
DisconnectButton.setEnabled(true);
DeviceInfo.setText("Device Information:");
DeviceName.setText(mDevice.getName() + " - Connected");
mState = UART_PROFILE_CONNECTED;
isConnected = true;
//IF COMMENTED THE APP CONNECTS!!!!!!!!!!!!!!!!!!
//ELSE IF NOT COMMENTED THE APP NEVER CONNECTS
/*if(isConnected) {
//Serial protocol to send command on MCU
Connectcmd[0] = (byte) STX;
Connectcmd[1] = (byte) 0x02;
Connectcmd[2] = (byte) 0x43; // 'C';
Connectcmd[3] = (byte) 0x54; // 'T'
Connectcmd[4] = (byte) ETX;
try {
//send data to UART service
SendData(Connectcmd);
sleep(500); // Wait 500ms to send data
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
new Handler().postDelayed(mUpdateTimeTask, 2000);
}
else
{
isConnected = false;
}*/
new Handler().postDelayed(mUpdateTimeTask, 2000);
}
});
}
//*********************//
if (action.equals(UartService.ACTION_GATT_DISCONNECTED)) {
runOnUiThread(new Runnable() {
public void run() {
Log.d(TAG, "HW_DISCONNECT_MSG");
DisconnectButton.setEnabled(false);
DeviceName.setText("Not Connected");
mState = UART_PROFILE_DISCONNECTED;
mService.close();
//setUiState();
}
});
}
//Enable notifivcation on UART service//
if (action.equals(UartService.ACTION_GATT_SERVICES_DISCOVERED)) {
mService.enableTXNotification();
}
//*********************//
if (action.equals(UartService.ACTION_DATA_AVAILABLE)) {
final byte[] txValue = intent.getByteArrayExtra(UartService.EXTRA_DATA);
try {
ParsingPacket(txValue);
} catch (Exception e) {
Log.e(TAG, e.toString());
}
}
//*********************//
if (action.equals(UartService.DEVICE_DOES_NOT_SUPPORT_BLE_UART)) {
showMessage("Device doesn't support UART over BLE Celu . Disconnecting");
mService.disconnect();
}
}
};
private static void ParsingPacket(byte[] packet) throws Exception {
if (packet.length == 0) {
// received empty packet
isConnected = false;
isSetting = false;
isReading = false;
isManual = false;
isFunctional = false;
isBootloader = false;
}
if(isSetting){
isSetting = false;
SettingValues = packet.clone();
String text = new String(SettingValues, "UTF-8");
Log.d(TAG, text);
}
if(isReading){
ReadingValues= packet;
ReadActivity.updateMeasure(ReadingValues);
//ReadActivity.addData(packet);
//String text = new String(ReadingValues, "UTF-8");
Log.d("Length ", String.format("%02d", (int) ReadingValues.length));
for(int i=0; i<ReadingValues.length; i++) {
String text = String.format("%02x", (int) ReadingValues[i]);
Log.d(TAG, text);
}
}
if(isManual){
isManual = false;
ManualValues = packet.clone();
String text = new String(ManualValues, "UTF-8");
Log.d(TAG, text);
}
if(isFunctional){
isFunctional = false;
FunctionalValues = packet.clone();
String text = new String(FunctionalValues, "UTF-8");
Log.d(TAG, text);
}
if(isBootloader){
isBootloader = false;
// do samething
}
}
private Runnable mUpdateTimeTask = new Runnable() {
public void run() {
if(DeviceName.getText()!="Not Connected") {
Intent connectedIntent = new Intent(getApplicationContext(), MenuActivity.class); //new Intent("com.antertech.mybleapplication.MenuActivity");
startActivity(connectedIntent);
}
}
};
private void service_init() {
Intent bindIntent = new Intent(this, UartService.class);
bindService(bindIntent, mServiceConnection, Context.BIND_AUTO_CREATE);
LocalBroadcastManager.getInstance(this).registerReceiver(UARTStatusChangeReceiver, makeGattUpdateIntentFilter());
}
private static IntentFilter makeGattUpdateIntentFilter() {
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(UartService.ACTION_GATT_CONNECTED);
intentFilter.addAction(UartService.ACTION_GATT_DISCONNECTED);
intentFilter.addAction(UartService.ACTION_GATT_SERVICES_DISCOVERED);
intentFilter.addAction(UartService.ACTION_DATA_AVAILABLE);
intentFilter.addAction(UartService.DEVICE_DOES_NOT_SUPPORT_BLE_UART);
return intentFilter;
}
#Override
public void onStart() {
super.onStart();// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.connect();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
AppIndex.AppIndexApi.start(client, getIndexApiAction());
}
#Override
public void onDestroy() {
super.onDestroy();
Log.d(TAG, "onDestroy()");
try {
LocalBroadcastManager.getInstance(this).unregisterReceiver(UARTStatusChangeReceiver);
} catch (Exception ignore) {
Log.e(TAG, ignore.toString());
}
unbindService(mServiceConnection);
mService.stopSelf();
mService = null;
}
#Override
protected void onStop() {
Log.d(TAG, "onStop");
super.onStop();// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
AppIndex.AppIndexApi.end(client, getIndexApiAction());
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.disconnect();
}
#Override
protected void onPause() {
Log.d(TAG, "onPause");
super.onPause();
}
#Override
protected void onRestart() {
super.onRestart();
Log.d(TAG, "onRestart");
}
#Override
public void onResume() {
super.onResume();
Log.d(TAG, "onResume");
if (!mBtAdapter.isEnabled()) {
Log.i(TAG, "onResume - BT not enabled yet");
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_SELECT_DEVICE:
//When the DeviceListActivity return, with the selected device address
if (resultCode == Activity.RESULT_OK && data != null) {
String deviceAddress = data.getStringExtra(BluetoothDevice.EXTRA_DEVICE);
mDevice = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(deviceAddress);
Log.d(TAG, "... onActivityResultdevice.address==" + mDevice + " mserviceValue " + mService);
mService.connect(deviceAddress);
//setContentView(R.layout.activity_setting);
((TextView) findViewById(R.id.deviceName)).setText(mDevice.getName() + " - Connecting...");
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
Toast.makeText(this, "Bluetooth has turned on ", Toast.LENGTH_SHORT).show();
} else {
// User did not enable Bluetooth or an error occurred
Log.d(TAG, "BT not enabled");
Toast.makeText(this, "Problem in BT Turning ON ", Toast.LENGTH_SHORT).show();
finish();
}
break;
default:
Log.e(TAG, "wrong request code");
break;
}
}
#Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
}
public static void SendData(byte[] text) {
mService.writeRXCharacteristic(text);
Log.i(TAG, "Message send to Target");
}
public static void disconnected() {
if (mDevice != null) {
mService.disconnect();
Log.i(TAG, "Push Button DISCONNECT");
}
}
private void showMessage(String msg) {
Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
}
#Override
public void onBackPressed() {
if (mState == UART_PROFILE_CONNECTED) {
Intent startMain = new Intent(Intent.ACTION_MAIN);
startMain.addCategory(Intent.CATEGORY_HOME);
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(startMain);
showMessage("CELU TPE running in background.\n Disconnect to exit");
} else {
new AlertDialog.Builder(this)
.setIcon(android.R.drawable.ic_dialog_alert)
.setTitle(R.string.popup_title)
.setMessage(R.string.popup_message)
.setPositiveButton(R.string.popup_yes, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
})
.setNegativeButton(R.string.popup_no, null)
.show();
}
}
#Override
public void onRequestPermissionsResult(int requestCode,
String permissions[],
int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_COARSE_LOCATION: {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "coarse location permission granted");
} else {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Functionality limited");
builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons when in the background.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
}
});
builder.show();
}
return;
}
}
}
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
public Action getIndexApiAction() {
Thing object = new Thing.Builder()
.setName("Main Page") // TODO: Define a title for the content shown.
// TODO: Make sure this auto-generated URL is correct.
.setUrl(Uri.parse("http://[ENTER-YOUR-URL-HERE]"))
.build();
return new Action.Builder(Action.TYPE_VIEW)
.setObject(object)
.setActionStatus(Action.STATUS_TYPE_COMPLETED)
.build();
}
}

Bluetooth Connection

I've looked at quite a lot of topics on this in different forums and none seem to help me.
I recently bought an Elegoo car kit, which is compatible with the Arduino IDE, and it comes with different types of code and what not. they even have their own Android app.
My problem is I want to create my own android Bluetooth application that connects/pairs with the module and can control the car remotely. I have my application up and running, it can scan for nearby devices and the HC-08 module appears in the list but I am not able to connect. when I try to connect it says it can't communicate with HC-08. I am pretty sure the problem lies in the android end as the elegoo Bluetooth app connects no problem at all with the Bluetooth module if there is any code on the elegoo board or not. The bluetooth module is a HC-08.
Can someone help me with this ?
Also I am following this youtube tutorial so the credit goes to him for the code.
https://www.youtube.com/watch?v=YJ0JQXcNNTA
Here is the main activity code:
public class MainActivity extends AppCompatActivity implements
AdapterView.OnItemClickListener{
private static final String TAG = "MainActivity";
BluetoothAdapter mBluetoothAdapter;
Button btnEnableDisable_Discoverable;
public ArrayList<BluetoothDevice> mBTDevices = new ArrayList<>();
public DeviceListAdapter mDeviceListAdapter;
ListView lvNewDevices;
// Create a BroadcastReceiver for ACTION_FOUND
private final BroadcastReceiver mBroadcastReceiver1 = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// When discovery finds a device
if (action.equals(mBluetoothAdapter.ACTION_STATE_CHANGED)) {
final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, mBluetoothAdapter.ERROR);
switch(state){
case BluetoothAdapter.STATE_OFF:
Log.d(TAG, "onReceive: STATE OFF");
break;
case BluetoothAdapter.STATE_TURNING_OFF:
Log.d(TAG, "mBroadcastReceiver1: STATE TURNING OFF");
break;
case BluetoothAdapter.STATE_ON:
Log.d(TAG, "mBroadcastReceiver1: STATE ON");
break;
case BluetoothAdapter.STATE_TURNING_ON:
Log.d(TAG, "mBroadcastReceiver1: STATE TURNING ON");
break;
}
}
}
};
/**
* Broadcast Receiver for changes made to bluetooth states such as:
* 1) Discoverability mode on/off or expire.
*/
private final BroadcastReceiver mBroadcastReceiver2 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (action.equals(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED)) {
int mode = intent.getIntExtra(BluetoothAdapter.EXTRA_SCAN_MODE, BluetoothAdapter.ERROR);
switch (mode) {
//Device is in Discoverable Mode
case BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE:
Log.d(TAG, "mBroadcastReceiver2: Discoverability Enabled.");
break;
//Device not in discoverable mode
case BluetoothAdapter.SCAN_MODE_CONNECTABLE:
Log.d(TAG, "mBroadcastReceiver2: Discoverability Disabled. Able to receive connections.");
break;
case BluetoothAdapter.SCAN_MODE_NONE:
Log.d(TAG, "mBroadcastReceiver2: Discoverability Disabled. Not able to receive connections.");
break;
case BluetoothAdapter.STATE_CONNECTING:
Log.d(TAG, "mBroadcastReceiver2: Connecting....");
break;
case BluetoothAdapter.STATE_CONNECTED:
Log.d(TAG, "mBroadcastReceiver2: Connected.");
break;
}
}
}
};
/**
* Broadcast Receiver for listing devices that are not yet paired
* -Executed by btnDiscover() method.
*/
private BroadcastReceiver mBroadcastReceiver3 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
Log.d(TAG, "onReceive: ACTION FOUND.");
if (action.equals(BluetoothDevice.ACTION_FOUND)){
BluetoothDevice device = intent.getParcelableExtra (BluetoothDevice.EXTRA_DEVICE);
mBTDevices.add(device);
Log.d(TAG, "onReceive: " + device.getName() + ": " + device.getAddress());
mDeviceListAdapter = new DeviceListAdapter(context, R.layout.device_adapter_view, mBTDevices);
lvNewDevices.setAdapter(mDeviceListAdapter);
}
}
};
/**
* Broadcast Receiver that detects bond state changes (Pairing status changes)
*/
private final BroadcastReceiver mBroadcastReceiver4 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if(action.equals(BluetoothDevice.ACTION_BOND_STATE_CHANGED)){
BluetoothDevice mDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//3 cases:
//case1: bonded already
if (mDevice.getBondState() == BluetoothDevice.BOND_BONDED){
Log.d(TAG, "BroadcastReceiver: BOND_BONDED.");
}
//case2: creating a bone
if (mDevice.getBondState() == BluetoothDevice.BOND_BONDING) {
Log.d(TAG, "BroadcastReceiver: BOND_BONDING.");
}
//case3: breaking a bond
if (mDevice.getBondState() == BluetoothDevice.BOND_NONE) {
Log.d(TAG, "BroadcastReceiver: BOND_NONE.");
}
}
}
};
#Override
protected void onDestroy() {
Log.d(TAG, "onDestroy: called.");
super.onDestroy();
unregisterReceiver(mBroadcastReceiver1);
unregisterReceiver(mBroadcastReceiver2);
unregisterReceiver(mBroadcastReceiver3);
unregisterReceiver(mBroadcastReceiver4);
//mBluetoothAdapter.cancelDiscovery();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnONOFF = (Button) findViewById(R.id.btnONOFF);
btnEnableDisable_Discoverable = (Button) findViewById(R.id.btnDiscoverable_on_off);
lvNewDevices = (ListView) findViewById(R.id.lvNewDevices);
mBTDevices = new ArrayList<>();
//Broadcasts when bond state changes (ie:pairing)
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
registerReceiver(mBroadcastReceiver4, filter);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
lvNewDevices.setOnItemClickListener(MainActivity.this);
btnONOFF.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d(TAG, "onClick: enabling/disabling bluetooth.");
enableDisableBT();
}
});
}
public void enableDisableBT(){
if(mBluetoothAdapter == null){
Log.d(TAG, "enableDisableBT: Does not have BT capabilities.");
}
if(!mBluetoothAdapter.isEnabled()){
Log.d(TAG, "enableDisableBT: enabling BT.");
Intent enableBTIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivity(enableBTIntent);
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
if(mBluetoothAdapter.isEnabled()){
Log.d(TAG, "enableDisableBT: disabling BT.");
mBluetoothAdapter.disable();
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
}
public void btnEnableDisable_Discoverable(View view) {
Log.d(TAG, "btnEnableDisable_Discoverable: Making device discoverable for 300 seconds.");
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
IntentFilter intentFilter = new IntentFilter(mBluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
registerReceiver(mBroadcastReceiver2,intentFilter);
}
public void btnDiscover(View view) {
Log.d(TAG, "btnDiscover: Looking for unpaired devices.");
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
Log.d(TAG, "btnDiscover: Canceling discovery.");
//check BT permissions in manifest
checkBTPermissions();
mBluetoothAdapter.startDiscovery();
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
}
if(!mBluetoothAdapter.isDiscovering()){
//check BT permissions in manifest
checkBTPermissions();
mBluetoothAdapter.startDiscovery();
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
}
}
/**
* This method is required for all devices running API23+
* Android must programmatically check the permissions for bluetooth. Putting the proper permissions
* in the manifest is not enough.
*
* NOTE: This will only execute on versions > LOLLIPOP because it is not needed otherwise.
*/
private void checkBTPermissions() {
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
if (permissionCheck != 0) {
this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1001); //Any number
}
}else{
Log.d(TAG, "checkBTPermissions: No need to check permissions. SDK version < LOLLIPOP.");
}
}
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
//first cancel discovery because its very memory intensive.
mBluetoothAdapter.cancelDiscovery();
Log.d(TAG, "onItemClick: You Clicked on a device.");
String deviceName = mBTDevices.get(i).getName();
String deviceAddress = mBTDevices.get(i).getAddress();
Log.d(TAG, "onItemClick: deviceName = " + deviceName);
Log.d(TAG, "onItemClick: deviceAddress = " + deviceAddress);
//create the bond.
//NOTE: Requires API 17+? I think this is JellyBean
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2){
Log.d(TAG, "Trying to pair with " + deviceName);
mBTDevices.get(i).createBond();
}
}
}
/// Here is also my DeviceListAdapter code:
public class DeviceListAdapter extends ArrayAdapter<BluetoothDevice> {
private LayoutInflater mLayoutInflater;
private ArrayList<BluetoothDevice> mDevices;
private int mViewResourceId;
public DeviceListAdapter(Context context, int tvResourceId, ArrayList<BluetoothDevice> devices){
super(context, tvResourceId,devices);
this.mDevices = devices;
mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mViewResourceId = tvResourceId;
}
public View getView(int position, View convertView, ViewGroup parent) {
convertView = mLayoutInflater.inflate(mViewResourceId, null);
BluetoothDevice device = mDevices.get(position);
if (device != null) {
TextView deviceName = (TextView) convertView.findViewById(R.id.tvDeviceName);
TextView deviceAdress = (TextView) convertView.findViewById(R.id.tvDeviceAddress);
if (deviceName != null) {
deviceName.setText(device.getName());
}
if (deviceAdress != null) {
deviceAdress.setText(device.getAddress());
}
}
return convertView;
}
}

Some of the tutorials on Bluetooth are pretty old! I just got Arduino-Android Bluetooth communication working last week so this should work for you! First in your manifest file add these permissions:
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
Then use this in your main.
public class MainActivity extends AppCompatActivity {
private final String DEVICE_ADDRESS="benamekhoda"; //I actually used Device Name instead of address
private final UUID PORT_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); //Serial Port Service UUID
private BluetoothDevice device; //Our Bluetooth Device
private BluetoothSocket socket;
private OutputStream outputStream;
private InputStream inputStream;
Button startButton, sendButton,clearButton,stopButton;
TextView textView;
EditText editText;
boolean deviceConnected=false;
Thread thread;
byte buffer[];
int bufferPosition;
boolean stopThread;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.edittext);
textView = (TextView) findViewById(R.id.textview);
startButton = (Button) findViewById(R.id.buttonStart);
startButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(BTinit())
{
if(BTconnect())
{
setUiEnabled(true);
deviceConnected=true;
beginListenForData();
textView.append("\nConnection Opened!\n");
}
else{
Toast.makeText(getApplicationContext(),"BTconnect false",Toast.LENGTH_SHORT).show();
}
}
else{
Toast.makeText(getApplicationContext(),"BTinit false",Toast.LENGTH_SHORT).show();
}
}
});
sendButton = (Button) findViewById(R.id.buttonSend);
sendButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String string = editText.getText().toString();
string.concat("\n");
try {
outputStream.write(string.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
textView.append("\nSent Data:"+string+"\n");
}
});
clearButton = (Button) findViewById(R.id.buttonClear);
clearButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onClickClear(view);
}
});
stopButton = (Button) findViewById(R.id.buttonStop);
stopButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onClickSend(view);
}
});
setUiEnabled(false);
}
public void setUiEnabled(boolean bool)
{
startButton.setEnabled(!bool);
sendButton.setEnabled(bool);
stopButton.setEnabled(bool);
textView.setEnabled(bool);
}
public boolean BTinit()
{
boolean found=false;
BluetoothAdapter bluetoothAdapter=BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
Toast.makeText(getApplicationContext(),"Device doesnt Support Bluetooth",Toast.LENGTH_SHORT).show();
}
if(!bluetoothAdapter.isEnabled())
{
Intent enableAdapter = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableAdapter, 0);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
Set<BluetoothDevice> bondedDevices = bluetoothAdapter.getBondedDevices(); //Something like ArrayList but no duplicate is allowed and data is unordered
if(bondedDevices.isEmpty())
{
Toast.makeText(getApplicationContext(),"Please Pair the Device first",Toast.LENGTH_SHORT).show();
}
else
{
for (BluetoothDevice iterator : bondedDevices)
{
if(iterator.getName().equals(DEVICE_ADDRESS))
{
device=iterator;
Toast.makeText(getApplicationContext(),"found the device",Toast.LENGTH_SHORT).show();
found=true;
break;
}
}
}
return found;
}
public boolean BTconnect()
{
boolean connected=true;
try {
socket = device.createRfcommSocketToServiceRecord(PORT_UUID);
socket.connect();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"throw1",Toast.LENGTH_SHORT).show();
connected=false;
}
if(connected)
{
try {
outputStream=socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"throw2",Toast.LENGTH_SHORT).show();
}
try {
inputStream=socket.getInputStream();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"throw3",Toast.LENGTH_SHORT).show();
}
}
return connected;
}
void beginListenForData()
{
final Handler handler = new Handler();
stopThread = false;
buffer = new byte[1024];
Thread thread = new Thread(new Runnable()
{
public void run()
{
while(!Thread.currentThread().isInterrupted() && !stopThread)
{
try
{
int byteCount = inputStream.available();
if(byteCount > 0)
{
byte[] rawBytes = new byte[byteCount];
inputStream.read(rawBytes);
final String string=new String(rawBytes,"UTF-8");
handler.post(new Runnable() {
public void run()
{
textView.append(string);
}
});
}
}
catch (IOException ex)
{
stopThread = true;
Toast.makeText(getApplicationContext(),"throw4",Toast.LENGTH_SHORT).show();
}
}
}
});
thread.start();
}
public void onClickSend(View view) {
String string = editText.getText().toString();
string.concat("\n");
try {
outputStream.write(string.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
textView.append("\nSent Data:"+string+"\n");
}
public void onClickStop(View view) throws IOException {
stopThread = true;
outputStream.close();
inputStream.close();
socket.close();
setUiEnabled(false);
deviceConnected=false;
textView.append("\nConnection Closed!\n");
}
public void onClickClear(View view) {
textView.setText("");
}
}
I got it from this awesome tutorial by Hariharan Mathavan from All About Circuits.

App crashed due to looper.prepare() in the beginlistendata() function

public class BluetoothActivity extends Activity {
// Create a BroadcastReceiver for ACTION_FOUND
private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// Whenever a remote Bluetooth device is found
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice bluetoothDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// Add the name and address to an array adapter to show in a ListView
adapter.add(bluetoothDevice.getName() + "\n"
+ bluetoothDevice.getAddress());
}
}
};
//declaration
TextView myLabel;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
volatile boolean stopWorker;
private BluetoothAdapter mBluetoothAdapter;
private ListView listview;
private ArrayAdapter adapter;
private ToggleButton toggleButton;
private static final int REQUEST_ENABLE_BT =0;
private static final int DISCOVERABLE_DURATION = 0;
private static final int DISCOVERABLE_BT_REQUEST_CODE = 2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.bluetooth_main);
toggleButton = (ToggleButton) findViewById(R.id.toggleButton);
listview = (ListView) findViewById(R.id.listView);
// ListView Item Click Listener
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// ListView Clicked item value
String itemValue = (String) listview.getItemAtPosition(position);
Toast.makeText(getApplicationContext(), "clicked", Toast.LENGTH_LONG).show();
String MAC = itemValue.substring(itemValue.length() - 17);
BluetoothDevice bluetoothDevice = mBluetoothAdapter.getRemoteDevice(MAC);
// Initiate a connection request in a separate thread
ConnectingThread t = new ConnectingThread(bluetoothDevice);
t.start();
}
});
adapter = new ArrayAdapter
(this,android.R.layout.simple_list_item_1);
listview.setAdapter(adapter);
//verify bluetooth is supported on the device
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// Device does not support Bluetooth
if (mBluetoothAdapter == null) {
}
}//end oncreate
public void onToggle(View view) {
adapter.clear();
if (toggleButton.isChecked()){
//enable bluetooth
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
Toast.makeText(getApplicationContext(), "Turned on", Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(getApplicationContext(),"Already on", Toast.LENGTH_LONG).show();
//To discover remote Bluetooth devices
discoverDevices();
// Make local device discoverable by other devices
makeDiscoverable();
}
}//end of 1st if
else{
//turn off bluetooth
mBluetoothAdapter.disable();
adapter.clear();
Toast.makeText(getApplicationContext(),"Turned off" ,Toast.LENGTH_LONG).show();
}
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_ENABLE_BT) {
// Bluetooth successfully enabled!
if (resultCode == Activity.RESULT_OK) {
Toast.makeText(getApplicationContext(), "Bluetooth is now enabled.",Toast.LENGTH_SHORT).show();
// Make local device discoverable by other devices
makeDiscoverable();
// To discover remote Bluetooth devices
Log.e("calldiscover", "func");
discoverDevices();
Log.e("Discover", "device");
// Start a thread to create a server socket to listen
// for connection request
Log.e("listenthread", "listenthread");
ListeningThread t = new ListeningThread();
Log.e("call", "t.start");
t.start();
Log.e("t.start", "over");
}
else {
// RESULT_CANCELED as user refused
Toast.makeText(getApplicationContext(), "Bluetooth is not enabled.",
Toast.LENGTH_SHORT).show();
// Turn off togglebutton
toggleButton.setChecked(false);
}
}//end of 1st if
}
protected void discoverDevices(){
// To scan for remote Bluetooth devices
if (mBluetoothAdapter.startDiscovery()) {Log.e("disc", "print");
Toast.makeText(getApplicationContext(), "Discovering other bluetooth devices...", Toast.LENGTH_SHORT).show();
}
else {
Log.e("print", "print");
Toast.makeText(getApplicationContext(), "Discovery failed to start.", Toast.LENGTH_SHORT).show();
}
}
protected void makeDiscoverable(){
// Make local device discoverable
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, DISCOVERABLE_DURATION);
startActivityForResult(discoverableIntent, DISCOVERABLE_BT_REQUEST_CODE);
}
#Override
protected void onResume() {
super.onResume();
// Register the BroadcastReceiver for ACTION_FOUND
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(broadcastReceiver, filter);
}
#Override
protected void onPause() {
super.onPause();
this.unregisterReceiver(broadcastReceiver);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private class ListeningThread extends Thread {
private final BluetoothServerSocket bluetoothServerSocket;
public ListeningThread() {
BluetoothServerSocket temp = null;
try {
temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(getString(R.string.app_name), uuid);
} catch (IOException e) {
e.printStackTrace();
}
bluetoothServerSocket = temp;
}
public void run() {
BluetoothSocket bluetoothSocket;
// This will block while listening until a BluetoothSocket is returned
// or an exception occurs
while (true) {
try {
Log.e("while", "over");
bluetoothSocket = bluetoothServerSocket.accept();
Log.e("bt", "accept");
} catch (IOException e) {Log.e("error", "catch");
break;
}
// If a connection is accepted
if (bluetoothSocket != null) {
Log.e("connection is accepted", "over");
BluetoothActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(BluetoothActivity.this, "Connected!", Toast.LENGTH_SHORT).show();
}
});
// Manage the connection in a separate thread
try {Log.e("callserver", "close");
bluetoothServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}//end of while
}
// Cancel the listening socket and terminate the thread
public void cancel() {
try {Log.e("cancel", "socket");
bluetoothServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//Setting Up a Connecting Client
private class ConnectingThread extends Thread {
OutputStream mmOutputStream;
InputStream mmInputStream;
private final BluetoothSocket bluetoothSocket;
private final BluetoothDevice bluetoothDevice;
public ConnectingThread(BluetoothDevice device) {
BluetoothSocket temp = null;
bluetoothDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try { Log.e("click6", "click6");
temp = bluetoothDevice.createRfcommSocketToServiceRecord(uuid);
} catch (IOException e) {
e.printStackTrace();
}
bluetoothSocket = temp;
}
public void run() {
// Cancel any discovery as it will slow down the connection
Log.e("click7", "click7");
mBluetoothAdapter.cancelDiscovery();
Log.e("click8", "click8");
try {
// This will block until it succeeds in connecting to the device
// through the bluetoothSocket or throws an exception
bluetoothSocket.connect();
mmOutputStream = bluetoothSocket.getOutputStream();
mmInputStream = bluetoothSocket.getInputStream();
beginListenForData();
Log.e("listendata", "lsitendata");
BluetoothActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(BluetoothActivity.this, "Connected with Device!", Toast.LENGTH_SHORT).show();
}
});
Log.e("click9", "click9");
} catch (IOException connectException) {
connectException.printStackTrace();
try {
bluetoothSocket.close();
Log.e("click6", "blueclose");
} catch (IOException closeException) {
closeException.printStackTrace();
}
}
}
void beginListenForData()
{
final Handler handler = new Handler();
final byte delimiter = 10; //This is the ASCII code for a newline character
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];//It uses a 1024 bytes long buffer because it doesn't have any way of knowing the length of the input stream.
workerThread = new Thread(new Runnable()
{
public void run()
{
while(!Thread.currentThread().isInterrupted() && !stopWorker)
{
try
{
int bytesAvailable = mmInputStream.available();
if(bytesAvailable > 0)
{
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for(int i=0;i<bytesAvailable;i++)
{
byte b = packetBytes[i];
if(b == delimiter)
{
byte[] encodedBytes = new byte[readBufferPosition];
System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
final String data = new String(encodedBytes, "US-ASCII");
readBufferPosition = 0;
handler.post(new Runnable()
{
public void run()
{
myLabel.setText(data);
}
});
}
else
{
readBuffer[readBufferPosition++] = b;
}
}
}
}
catch (IOException ex)
{
stopWorker = true;
}
}
}
});
workerThread.start();
}
Hi the app crashed when I try to call beginListenForData(); The error state that Can't create handler inside thread that has not called Looper.prepare()
Does anyone know what wrong? I am new to android. Please help.
Bluetooth.xml below
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".BluetoothActivity">
<ToggleButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOn="Turn off Bluetooth"
android:textOff="Turn on Bluetooth"
android:id="#+id/toggleButton"
android:onClick="onToggle"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/listView"
android:layout_alignParentStart="true"
android:layout_marginStart="76dp"
android:layout_below="#+id/toggleButton" />
<TextView
android:id="#+id/label"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Type here:"
android:layout_below="#+id/toggleButton"
android:layout_centerHorizontal="true"
android:layout_marginTop="66dp" />
</RelativeLayout>

Try this inside beginListenForData()
Replace
final Handler handler = new Handler();
With this
final Handler handler = new Handler(Looper.getMainLooper());

Bluetooth device name pass to another activity. Connection not connected in another activity

Hi everyone..
I have used android Bluetooth chat application code in my application
I want pass a device name to another activity so i have saved my device name in public static variable when i select device name from list view same as android chat application.
After that i used this device name in another activity .With the help of this device name i Started BluetoothChatservice in second activity same as bluetooth chat standard code example.I didnt used this services in my mainactivity because I want connect device in my second activity
I have used Secure key only.But when i satarted this service sometimes connection connected with my another devices or sometimes not .
When i try for connection from both side connection connected.But first time it is not connect .I have used many things for service start like in onResume or ONStart or OnCreate but i am not success ed. MY english not good so please read carefully.
MY Main Activity Code=======
public static String EXTRA_DEVICE_ADDRESS = "device_address";
// Member fields
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
private ArrayAdapter<String> mNewDevicesArrayAdapter;
// Debugging
private static final String TAG = "BluetoothChat";
private static final boolean D = true;
// Key names received from the BluetoothChatService Handler
public static final String DEVICE_NAME = "device_name";
public static final String TOAST = "toast";
// Intent request codes
private static final int REQUEST_CONNECT_DEVICE_SECURE = 1;
private static final int REQUEST_CONNECT_DEVICE_INSECURE = 2;
private static final int REQUEST_ENABLE_BT = 3;
// Layout Views
private TextView mTitle;
private ListView mConversationView;
private EditText mOutEditText;
private Button mSendButton;
private Button mSearch;
// Name of the connected device
private String mConnectedDeviceName = null;
// Array adapter for the conversation thread
private ArrayAdapter<String> mConversationArrayAdapter;
// String buffer for outgoing messages
private StringBuffer mOutStringBuffer;
// Local Bluetooth adapter
public static BluetoothAdapter mBluetoothAdapter = null;
private LinearLayout mLin_getView;
#SuppressLint("NewApi")
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(D) Log.e(TAG, "+++ ON CREATE +++");
// Set up the window layout
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.main);
// Set up the custom title
mLin_getView=(LinearLayout) findViewById(R.id.mLin_addView);
// Get local Bluetooth adapter
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// If the adapter is null, then Bluetooth is not supported
if (mBluetoothAdapter == null) {
Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show();
finish();
return;
}
}
#SuppressLint("NewApi")
#Override
public void onStart() {
super.onStart();
if(D) Log.e(TAG, "++ ON START ++");
// If BT is not on, request that it be enabled.
// setupChat() will then be called during onActivityResult
if (!mBluetoothAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
// Otherwise, setup the chat session
} else {
//if (mChatService == null)
setupChat();
}
}
#Override
public synchronized void onResume() {
super.onResume();
if(D) Log.e(TAG, "+ ON RESUME +");
// Performing this check in onResume() covers the case in which BT was
// not enabled during onStart(), so we were paused to enable it...
// onResume() will be called when ACTION_REQUEST_ENABLE activity returns.
}
#SuppressLint("NewApi")
private void setupChat() {
Log.d(TAG, "setupChat()");
mSearch = (Button) findViewById(R.id.btn_search);
mSearch.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// Send a message using content of the edit text widget
initilizeFiled();
/*Intent serverIntent = new Intent(BluetoothChat.this, DeviceListActivity.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE);*/
}
});
mOutStringBuffer = new StringBuffer("");
}
protected void initilizeFiled() {
// TODO Auto-generated method stub
Button scanButton = (Button) findViewById(R.id.button_scan);
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
// Find and set up the ListView for paired devices
ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
pairedListView.setAdapter(mPairedDevicesArrayAdapter);
pairedListView.setOnItemClickListener(mDeviceClickListener);
// Find and set up the ListView for newly discovered devices
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
newDevicesListView.setOnItemClickListener(mDeviceClickListener);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
// Get the local Bluetooth adapter
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
// Get a set of currently paired devices
Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice device : pairedDevices) {
mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
String noDevices = getResources().getText(R.string.none_paired).toString();
mPairedDevicesArrayAdapter.add(noDevices);
}
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
#SuppressLint("NewApi")
#Override
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);
// If it's already paired, skip it, because it's been listed already
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
// The on-click listener for all devices in the ListViews
private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
// Cancel discovery because it's costly and we're about to connect
mBtAdapter.cancelDiscovery();
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
Log.d("Device Address", address);
connectDevice(address, true);
}
};
#SuppressLint("NewApi")
private void doDiscovery() {
if (D) Log.d(TAG, "doDiscovery()");
// Indicate scanning in the title
setProgressBarIndeterminateVisibility(true);
setTitle(R.string.scanning);
// Turn on sub-title for new devices
findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
// If we're already discovering, stop it
if (mBtAdapter.isDiscovering()) {
mBtAdapter.cancelDiscovery();
}
// Request discover from BluetoothAdapter
mBtAdapter.startDiscovery();
}
#Override
public synchronized void onPause() {
super.onPause();
if(D) Log.e(TAG, "- ON PAUSE -");
if (mBtAdapter != null) {
mBtAdapter.cancelDiscovery();
}
}
#Override
public void onStop() {
super.onStop();
if(D) Log.e(TAG, "-- ON STOP --");
}
#Override
public void onDestroy() {
super.onDestroy();
// Stop the Bluetooth chat services
//if (mChatService != null) mChatService.stop();
if(D) Log.e(TAG, "--- ON DESTROY ---");
if (mBtAdapter != null) {
mBtAdapter.cancelDiscovery();
}
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}
// The Handler that gets information back from the BluetoothChatService
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if(D) Log.d(TAG, "onActivityResult " + resultCode);
switch (requestCode) {
case REQUEST_CONNECT_DEVICE_SECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
// connectDevice(data, true);
}
break;
case REQUEST_CONNECT_DEVICE_INSECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
// connectDevice(data, false);
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
setupChat();
} else {
// User did not enable Bluetooth or an error occured
Log.d(TAG, "BT not enabled");
Toast.makeText(this, R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show();
finish();
}
}
}
private void connectDevice(String Address,boolean secure) {
// Get the device MAC address
String address = Address;
// Get the BLuetoothDevice object
// BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
Const.deviceName=device;
Intent ib=new Intent(DashboardActivity.this,RemmoteActivity.class);
startActivity(ib);
}
}
Second Activity=========
private BluetoothAdapter mBluetoothAdapter = null;
private String mConnectedDeviceName = null;
public static final int MESSAGE_STATE_CHANGE = 1;
public static final int MESSAGE_READ = 2;
public static final int MESSAGE_WRITE = 3;
public static final int MESSAGE_DEVICE_NAME = 4;
public static final int MESSAGE_TOAST = 5;
String TAG="Remmote";
// Key names received from the BluetoothChatService Handler
public static final String DEVICE_NAME = "device_name";
public static final String TOAST = "toast";
ImageView Img_video, Img_camera, Img_song, Img_play, Img_forward,
Img_backward, Img_volume_up, Img_volume_down, Img_splash,
Img_capture, Img_zoom_in, Img_zoom_out;
private BluetoothChatService mChatService=null;
private StringBuffer mOutStringBuffer;
private BluetoothDevice device_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_remote_screen);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mChatService=new BluetoothChatService(this,mHandler);
mOutStringBuffer=new StringBuffer("");
mOutStringBuffer=new StringBuffer("");
device_Name=Const.device;
if (mChatService != null) {
// Only if the state is STATE_NONE, do we know that we haven't started already
if (mChatService.getState() == BluetoothChatService.STATE_NONE) {
// Start the Bluetooth chat services
mChatService.start();
}
}
initilizeField();
}
public void onStart() {
super.onStart();
Log.print(TAG, "++ ON START ++");
// If BT is not on, request that it be enabled.
// setupChat() will then be called during onActivityResult
if (!mBluetoothAdapter.isEnabled()) {
Toast.makeText(getApplicationContext(), "Bluetooth Device Enabled", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Bluetooth Device Enabled", Toast.LENGTH_SHORT).show();
}
}
#Override
public synchronized void onResume() {
super.onResume();
Log.print(TAG, "+ ON RESUME +");
mChatService.connect(device_Name, true);
}
#Override
public synchronized void onPause() {
super.onPause();
Log.print(TAG, "- ON PAUSE -");
}
#Override
public void onStop() {
super.onStop();
Log.print(TAG, "-- ON STOP --");
}
#Override
public void onDestroy() {
super.onDestroy();
// Stop the Bluetooth chat services
if (mChatService != null) mChatService.stop();
Log.print(TAG, "--- ON DESTROY ---");
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.mImg_camera:
sendMessage("Camera");
break;
case R.id.mImg_video:
break;
case R.id.mImg_songs:
break;
case R.id.Img_play:
break;
case R.id.Img_forward:
break;
case R.id.Img_backward:
break;
case R.id.Img_volume_up:
break;
default:
break;
}
}
public void sendMessage(String message) {
// Check that we're actually connected before trying anything
if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
// Check that there's actually something to send
if (message.length() > 0) {
// Get the message bytes and tell the BluetoothChatService to write
byte[] send = message.getBytes();
mChatService.write(send);
// Reset out string buffer to zero and clear the edit text field
mOutStringBuffer.setLength(0);
// mOutEditText.setText(mOutStringBuffer);77
}
}
private final Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case Const.Camera:
com.example.utils.Log.print("your tab is here====="+1000);
//BluetoothChat.this.sendMessage("Camera");
break;
case MESSAGE_STATE_CHANGE:
Log.print(TAG, "MESSAGE_STATE_CHANGE: " + msg.arg1);
switch (msg.arg1) {
case BluetoothChatService.STATE_CONNECTED:
Toast.makeText(getApplicationContext(), "STATE_CONNECTED", Toast.LENGTH_SHORT).show();
break;
case BluetoothChatService.STATE_CONNECTING:
Toast.makeText(getApplicationContext(), "STATE_CONNECTING", Toast.LENGTH_SHORT).show();
break;
case BluetoothChatService.STATE_LISTEN:
case BluetoothChatService.STATE_NONE:
Toast.makeText(getApplicationContext(), "STATE_NOT_LISTEN", Toast.LENGTH_SHORT).show();
break;
}
break;
case MESSAGE_WRITE:
byte[] writeBuf = (byte[]) msg.obj;
// construct a string from the buffer
String writeMessage = new String(writeBuf);
Toast.makeText(getApplicationContext(), writeMessage, Toast.LENGTH_SHORT).show();
//mConversationArrayAdapter.add("Me: " + writeMessage);
break;
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
Toast.makeText(getApplicationContext(), "Read", Toast.LENGTH_SHORT).show();
// captureImage();
// mConversationArrayAdapter.add(mConnectedDeviceName+": " + readMessage);
break;
case MESSAGE_DEVICE_NAME:
// save the connected device's name
mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);
Toast.makeText(getApplicationContext(), "Connected to "
+ mConnectedDeviceName, Toast.LENGTH_SHORT).show();
break;
case MESSAGE_TOAST:
Toast.makeText(getApplicationContext(), msg.getData().getString(TOAST),
Toast.LENGTH_SHORT).show();
break;
}
}
};
In const Class for public static varible
public static BluetoothDevice device;
BluetoothChatService Code Same as android default program example

Android + Pair devices via bluetooth programmatically

I want to discover bluetooth devices in range, list and pair to them on click. I used following code but its just closing application when I click on device name which I want to pair.
I want to know mistake in my code or any other way to do what i need.
package com.marakana;
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class BluetoothDemo extends Activity {
// Debugging
private static final String TAG = "DeviceListActivity";
private static final boolean D = true;
// Return Intent extra
public static String EXTRA_DEVICE_ADDRESS = "device_address";
// Member fields
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
private ArrayAdapter<String> mNewDevicesArrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Setup the window
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.device_list);
// Set result CANCELED incase the user backs out
setResult(Activity.RESULT_CANCELED);
// Initialize the button to perform device discovery
Button scanButton = (Button) findViewById(R.id.button_scan);
scanButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
doDiscovery();
v.setVisibility(View.GONE);
}
});
// Initialize array adapters. One for already paired devices and
// one for newly discovered devices
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
// Find and set up the ListView for paired devices
ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
pairedListView.setAdapter(mPairedDevicesArrayAdapter);
pairedListView.setOnItemClickListener(mDeviceClickListener);
// Find and set up the ListView for newly discovered devices
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
newDevicesListView.setOnItemClickListener(mDeviceClickListener);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
// Get the local Bluetooth adapter
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
// Get a set of currently paired devices
Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice device : pairedDevices) {
mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
String noDevices = getResources().getText(R.string.none_paired).toString();
mPairedDevicesArrayAdapter.add(noDevices);
}
}
#Override
protected void onDestroy() {
super.onDestroy();
// Make sure we're not doing discovery anymore
if (mBtAdapter != null) {
mBtAdapter.cancelDiscovery();
}
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}
/**
* Start device discover with the BluetoothAdapter
*/
private void doDiscovery() {
if (D) Log.d(TAG, "doDiscovery()");
// Indicate scanning in the title
setProgressBarIndeterminateVisibility(true);
setTitle(R.string.scanning);
// Turn on sub-title for new devices
findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
// If we're already discovering, stop it
if (mBtAdapter.isDiscovering()) {
mBtAdapter.cancelDiscovery();
}
// Request discover from BluetoothAdapter
mBtAdapter.startDiscovery();
}
// The on-click listener for all devices in the ListViews
private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
// Cancel discovery because it's costly and we're about to connect
mBtAdapter.cancelDiscovery();
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
// Create the result Intent and include the MAC address
Intent intent = new Intent();
intent.putExtra(EXTRA_DEVICE_ADDRESS, address);
// Set result and finish this Activity
setResult(Activity.RESULT_OK, intent);
finish();
}
};
// The BroadcastReceiver that listens for discovered devices and
// changes the title when discovery is finished
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
#Override
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);
// If it's already paired, skip it, because it's been listed already
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
}

In my first answer the logic is shown for those who want to go with the logic only.
I think I was not able to make clear to #chalukya3545, that's why I am adding the whole code to let him know the exact flow of the code.
BluetoothDemo.java
public class BluetoothDemo extends Activity {
ListView listViewPaired;
ListView listViewDetected;
ArrayList<String> arrayListpaired;
Button buttonSearch,buttonOn,buttonDesc,buttonOff;
ArrayAdapter<String> adapter,detectedAdapter;
static HandleSeacrh handleSeacrh;
BluetoothDevice bdDevice;
BluetoothClass bdClass;
ArrayList<BluetoothDevice> arrayListPairedBluetoothDevices;
private ButtonClicked clicked;
ListItemClickedonPaired listItemClickedonPaired;
BluetoothAdapter bluetoothAdapter = null;
ArrayList<BluetoothDevice> arrayListBluetoothDevices = null;
ListItemClicked listItemClicked;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listViewDetected = (ListView) findViewById(R.id.listViewDetected);
listViewPaired = (ListView) findViewById(R.id.listViewPaired);
buttonSearch = (Button) findViewById(R.id.buttonSearch);
buttonOn = (Button) findViewById(R.id.buttonOn);
buttonDesc = (Button) findViewById(R.id.buttonDesc);
buttonOff = (Button) findViewById(R.id.buttonOff);
arrayListpaired = new ArrayList<String>();
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
clicked = new ButtonClicked();
handleSeacrh = new HandleSeacrh();
arrayListPairedBluetoothDevices = new ArrayList<BluetoothDevice>();
/*
* the above declaration is just for getting the paired bluetooth devices;
* this helps in the removing the bond between paired devices.
*/
listItemClickedonPaired = new ListItemClickedonPaired();
arrayListBluetoothDevices = new ArrayList<BluetoothDevice>();
adapter= new ArrayAdapter<String>(BluetoothDemo.this, android.R.layout.simple_list_item_1, arrayListpaired);
detectedAdapter = new ArrayAdapter<String>(BluetoothDemo.this, android.R.layout.simple_list_item_single_choice);
listViewDetected.setAdapter(detectedAdapter);
listItemClicked = new ListItemClicked();
detectedAdapter.notifyDataSetChanged();
listViewPaired.setAdapter(adapter);
}
#Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
getPairedDevices();
buttonOn.setOnClickListener(clicked);
buttonSearch.setOnClickListener(clicked);
buttonDesc.setOnClickListener(clicked);
buttonOff.setOnClickListener(clicked);
listViewDetected.setOnItemClickListener(listItemClicked);
listViewPaired.setOnItemClickListener(listItemClickedonPaired);
}
private void getPairedDevices() {
Set<BluetoothDevice> pairedDevice = bluetoothAdapter.getBondedDevices();
if(pairedDevice.size()>0)
{
for(BluetoothDevice device : pairedDevice)
{
arrayListpaired.add(device.getName()+"\n"+device.getAddress());
arrayListPairedBluetoothDevices.add(device);
}
}
adapter.notifyDataSetChanged();
}
class ListItemClicked implements OnItemClickListener
{
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// TODO Auto-generated method stub
bdDevice = arrayListBluetoothDevices.get(position);
//bdClass = arrayListBluetoothDevices.get(position);
Log.i("Log", "The dvice : "+bdDevice.toString());
/*
* here below we can do pairing without calling the callthread(), we can directly call the
* connect(). but for the safer side we must usethe threading object.
*/
//callThread();
//connect(bdDevice);
Boolean isBonded = false;
try {
isBonded = createBond(bdDevice);
if(isBonded)
{
//arrayListpaired.add(bdDevice.getName()+"\n"+bdDevice.getAddress());
//adapter.notifyDataSetChanged();
getPairedDevices();
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
e.printStackTrace();
}//connect(bdDevice);
Log.i("Log", "The bond is created: "+isBonded);
}
}
class ListItemClickedonPaired implements OnItemClickListener
{
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,long id) {
bdDevice = arrayListPairedBluetoothDevices.get(position);
try {
Boolean removeBonding = removeBond(bdDevice);
if(removeBonding)
{
arrayListpaired.remove(position);
adapter.notifyDataSetChanged();
}
Log.i("Log", "Removed"+removeBonding);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/*private void callThread() {
new Thread(){
public void run() {
Boolean isBonded = false;
try {
isBonded = createBond(bdDevice);
if(isBonded)
{
arrayListpaired.add(bdDevice.getName()+"\n"+bdDevice.getAddress());
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//connect(bdDevice);
Log.i("Log", "The bond is created: "+isBonded);
}
}.start();
}*/
private Boolean connect(BluetoothDevice bdDevice) {
Boolean bool = false;
try {
Log.i("Log", "service method is called ");
Class cl = Class.forName("android.bluetooth.BluetoothDevice");
Class[] par = {};
Method method = cl.getMethod("createBond", par);
Object[] args = {};
bool = (Boolean) method.invoke(bdDevice);//, args);// this invoke creates the detected devices paired.
//Log.i("Log", "This is: "+bool.booleanValue());
//Log.i("Log", "devicesss: "+bdDevice.getName());
} catch (Exception e) {
Log.i("Log", "Inside catch of serviceFromDevice Method");
e.printStackTrace();
}
return bool.booleanValue();
};
public boolean removeBond(BluetoothDevice btDevice)
throws Exception
{
Class btClass = Class.forName("android.bluetooth.BluetoothDevice");
Method removeBondMethod = btClass.getMethod("removeBond");
Boolean returnValue = (Boolean) removeBondMethod.invoke(btDevice);
return returnValue.booleanValue();
}
public boolean createBond(BluetoothDevice btDevice)
throws Exception
{
Class class1 = Class.forName("android.bluetooth.BluetoothDevice");
Method createBondMethod = class1.getMethod("createBond");
Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);
return returnValue.booleanValue();
}
class ButtonClicked implements OnClickListener
{
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.buttonOn:
onBluetooth();
break;
case R.id.buttonSearch:
arrayListBluetoothDevices.clear();
startSearching();
break;
case R.id.buttonDesc:
makeDiscoverable();
break;
case R.id.buttonOff:
offBluetooth();
break;
default:
break;
}
}
}
private BroadcastReceiver myReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Message msg = Message.obtain();
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)){
Toast.makeText(context, "ACTION_FOUND", Toast.LENGTH_SHORT).show();
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
try
{
//device.getClass().getMethod("setPairingConfirmation", boolean.class).invoke(device, true);
//device.getClass().getMethod("cancelPairingUserInput", boolean.class).invoke(device);
}
catch (Exception e) {
Log.i("Log", "Inside the exception: ");
e.printStackTrace();
}
if(arrayListBluetoothDevices.size()<1) // this checks if the size of bluetooth device is 0,then add the
{ // device to the arraylist.
detectedAdapter.add(device.getName()+"\n"+device.getAddress());
arrayListBluetoothDevices.add(device);
detectedAdapter.notifyDataSetChanged();
}
else
{
boolean flag = true; // flag to indicate that particular device is already in the arlist or not
for(int i = 0; i<arrayListBluetoothDevices.size();i++)
{
if(device.getAddress().equals(arrayListBluetoothDevices.get(i).getAddress()))
{
flag = false;
}
}
if(flag == true)
{
detectedAdapter.add(device.getName()+"\n"+device.getAddress());
arrayListBluetoothDevices.add(device);
detectedAdapter.notifyDataSetChanged();
}
}
}
}
};
private void startSearching() {
Log.i("Log", "in the start searching method");
IntentFilter intentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
BluetoothDemo.this.registerReceiver(myReceiver, intentFilter);
bluetoothAdapter.startDiscovery();
}
private void onBluetooth() {
if(!bluetoothAdapter.isEnabled())
{
bluetoothAdapter.enable();
Log.i("Log", "Bluetooth is Enabled");
}
}
private void offBluetooth() {
if(bluetoothAdapter.isEnabled())
{
bluetoothAdapter.disable();
}
}
private void makeDiscoverable() {
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
Log.i("Log", "Discoverable ");
}
class HandleSeacrh extends Handler
{
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 111:
break;
default:
break;
}
}
}
}
Here is the main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="#+id/buttonOn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="On"/>
<Button
android:id="#+id/buttonDesc"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Make Discoverable"/>
<Button
android:id="#+id/buttonSearch"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Search"/>
<Button
android:id="#+id/buttonOff"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Bluetooth Off"/>
<ListView
android:id="#+id/listViewPaired"
android:layout_width="match_parent"
android:layout_height="120dp">
</ListView>
<ListView
android:id="#+id/listViewDetected"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
</LinearLayout>
Add this permissions to your AndroidManifest.xml file:
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
The output for this code will look like this.

The Best way is do not use any pairing code.
Instead of onClick go to other function or other class where You create the socket using UUID.
Android automatically pops up for pairing if already not paired.
or see this link for better understanding
Below is code for the same:
private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
// Cancel discovery because it's costly and we're about to connect
mBtAdapter.cancelDiscovery();
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
// Create the result Intent and include the MAC address
Intent intent = new Intent();
intent.putExtra(EXTRA_DEVICE_ADDRESS, address);
// Set result and finish this Activity
setResult(Activity.RESULT_OK, intent);
// **add this 2 line code**
Intent myIntent = new Intent(view.getContext(), Connect.class);
startActivityForResult(myIntent, 0);
finish();
}
};
Connect.java file is :
public class Connect extends Activity {
private static final String TAG = "zeoconnect";
private ByteBuffer localByteBuffer;
private InputStream in;
byte[] arrayOfByte = new byte[4096];
int bytes;
public BluetoothDevice mDevice;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.connect);
try {
setup();
} catch (ZeoMessageException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ZeoMessageParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void setup() throws ZeoMessageException, ZeoMessageParseException {
// TODO Auto-generated method stub
getApplicationContext().registerReceiver(receiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));
getApplicationContext().registerReceiver(receiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED));
BluetoothDevice zee = BluetoothAdapter.getDefaultAdapter().
getRemoteDevice("**:**:**:**:**:**");// add device mac adress
try {
sock = zee.createRfcommSocketToServiceRecord(
UUID.fromString("*******************")); // use unique UUID
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d(TAG, "++++ Connecting");
try {
sock.connect();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d(TAG, "++++ Connected");
try {
in = sock.getInputStream();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d(TAG, "++++ Listening...");
while (true) {
try {
bytes = in.read(arrayOfByte);
Log.d(TAG, "++++ Read "+ bytes +" bytes");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d(TAG, "++++ Done: test()");
}}
private static final LogBroadcastReceiver receiver = new LogBroadcastReceiver();
public static class LogBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context paramAnonymousContext, Intent paramAnonymousIntent) {
Log.d("ZeoReceiver", paramAnonymousIntent.toString());
Bundle extras = paramAnonymousIntent.getExtras();
for (String k : extras.keySet()) {
Log.d("ZeoReceiver", " Extra: "+ extras.get(k).toString());
}
}
};
private BluetoothSocket sock;
#Override
public void onDestroy() {
getApplicationContext().unregisterReceiver(receiver);
if (sock != null) {
try {
sock.close();
} catch (IOException e) {
e.printStackTrace();
}
}
super.onDestroy();
}
}

if you have the BluetoothDevice object you can create bond(pair) from api 19 onwards with bluetoothDevice.createBond() method.
Edit
for callback, if the request was accepted or denied you will have to create a BroadcastReceiver with BluetoothDevice.ACTION_BOND_STATE_CHANGED action

Edit: I have just explained logic to pair here. If anybody want to go with the complete code then see my another answer. I have answered here for logic only but I was not able to explain properly, So I have added another answer in the same thread.
Try this to do pairing:
If you are able to search the devices then this would be your next step
ArrayList<BluetoothDevice> arrayListBluetoothDevices = NEW ArrayList<BluetoothDevice>;
I am assuming that you have the list of Bluetooth devices added in the arrayListBluetoothDevices:
BluetoothDevice bdDevice;
bdDevice = arrayListBluetoothDevices.get(PASS_THE_POSITION_TO_GET_THE_BLUETOOTH_DEVICE);
Boolean isBonded = false;
try {
isBonded = createBond(bdDevice);
if(isBonded)
{
Log.i("Log","Paired");
}
} catch (Exception e)
{
e.printStackTrace();
}
The createBond() method:
public boolean createBond(BluetoothDevice btDevice)
throws Exception
{
Class class1 = Class.forName("android.bluetooth.BluetoothDevice");
Method createBondMethod = class1.getMethod("createBond");
Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);
return returnValue.booleanValue();
}
Add this line into your Receiver in the ACTION_FOUND
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
arrayListBluetoothDevices.add(device);
}