BluetoothSPP bt = new BluetoothSPP(Context);

if(!bt.isBluetoothAvailable()) {
    // any command for bluetooth is not available
}

public void onStart() {
    super.onStart();
    if(!bt.isBluetoothEnable()) {
        // Do somthing if bluetooth is disable
    } else {
        // Do something if bluetooth is already enable
    }
}

bt.startService(BluetoothState.DEVICE_ANDROID);

bt.startService(BluetoothState.DEVICE_OTHER);

bt.stopService();

Intent intent = new Intent(getApplicationContext(), DeviceList.class);
startActivityForResult(intent, BluetoothState.REQUEST_CONNECT_DEVICE);

<activity android:name="app.akexorcist.bluetoothspp.DeviceList" />

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(requestCode == BluetoothState.REQUEST_CONNECT_DEVICE) {
        if(resultCode == Activity.RESULT_OK)
            bt.connect(data);
    } else if(requestCode == BluetoothState.REQUEST_ENABLE_BT) {
        if(resultCode == Activity.RESULT_OK) {
            bt.setupService();
            bt.startService(BluetoothState.DEVICE_ANDROID);
            setup();
        } else {
            // Do something if user doesn't choose any device (Pressed back)
        }
    }
}

bt.send("Message", true);

bt.send(new byte[] { 0x30, 0x38, ....}, false);

bt.setOnDataReceivedListener(new OnDataReceivedListener() {
    public void onDataReceived(byte[] data, String message) {
        // Do something when data incoming
    }
});

bt.setBluetoothConnectionListener(new BluetoothConnectionListener() {
    public void onDeviceConnected(String name, String address) {
        // Do something when successfully connected
    }

    public void onDeviceDisconnected() {
        // Do something when connection was disconnected
    }

    public void onDeviceConnectionFailed() {
        // Do something when connection failed
    }
});

bt.setBluetoothStateListener(new BluetoothStateListener() {                
    public void onServiceStateChanged(int state) {
        if(state == BluetoothState.STATE_CONNECTED)
            // Do something when successfully connected
        else if(state == BluetoothState.STATE_CONNECTING)
            // Do something while connecting
        else if(state == BluetoothState.STATE_LISTEN)
            // Do something when device is waiting for connection
        else if(state == BluetoothState.STATE_NONE)
            // Do something when device don't have any connection
    }
});

bt.autoConnect("Keyword for filter paired device");

bt.setAutoConnectionListener(new AutoConnectionListener() {
    public void onNewConnection(String name, String address) {
        // Do something when earching for new connection device
    }
            
    public void onAutoConnectionStarted() {
        // Do something when auto connection has started
    }
});

Intent intent = new Intent(getApplicationContext(), DeviceList.class);
intent.putExtra("bluetooth_devices", "Bluetooth devices");
intent.putExtra("no_devices_found", "No device");
intent.putExtra("scanning", "กำลังทำการค้นหา");
intent.putExtra("scan_for_devices", "Search");
intent.putExtra("select_device", "Select");
startActivityForResult(intent, BluetoothState.REQUEST_CONNECT_DEVICE);