Large data transmission in Bluetooth Low Energy be

Question

Have an issue receiving data from HM-10 Bluetooth Low Energy in my android App I did half the way. what I did is : sending data from the phone to the BLE and i succeeded now i want to receive data to my phone from the BLE. (Arduino) --> (HM-10 BLE) ->-->-BLE CONNECTION-->-->- (ANDROID APP) So I'm sending dummy data from Arduino but I cannot receive it in the app.

here's the class that responsible to send data from Android to the BLE Module

public class DeviceControlActivity extends Activity {
    private final static String TAG = DeviceControlActivity.class.getSimpleName();

    public static final String DEVICE1_ON = "0";
    public static final String DEVICE1_OFF = "1";
    public static final String DEVICE2_ON = "2";
    public static final String DEVICE2_OFF = "3";

    public static final String EXTRAS_DEVICE_NAME = "DEVICE_NAME";
    public static final String EXTRAS_DEVICE_ADDRESS = "DEVICE_ADDRESS";
    private int[] RGBFrame = {0, 0, 0};
    private TextView isSerial;
    private TextView mConnectionState;
    private ToggleButton toggle1, toggle2;
    private String mDeviceName;
    private String mDeviceAddress;
    //  private ExpandableListView mGattServicesList;
    private BluetoothLeService mBluetoothLeService;
    private boolean mConnected = false;
    private BluetoothGattCharacteristic characteristicTX;
    private BluetoothGattCharacteristic characteristicRX;


    public final static UUID HM_RX_TX =
            UUID.fromString(SampleGattAttributes.HM_RX_TX);

    private final String LIST_NAME = "NAME";
    private final String LIST_UUID = "UUID";

    // Code to manage Service lifecycle.
    private final ServiceConnection mServiceConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName componentName, IBinder service) {
            mBluetoothLeService = ((BluetoothLeService.LocalBinder) service).getService();
            if (!mBluetoothLeService.initialize()) {
                Log.e(TAG, "Unable to initialize Bluetooth");
                finish();
            }
            // Automatically connects to the device upon successful start-up initialization.
            mBluetoothLeService.connect(mDeviceAddress);
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            mBluetoothLeService = null;
        }
    };

    // Handles various events fired by the Service.
    // ACTION_GATT_CONNECTED: connected to a GATT server.
    // ACTION_GATT_DISCONNECTED: disconnected from a GATT server.
    // ACTION_GATT_SERVICES_DISCOVERED: discovered GATT services.
    // ACTION_DATA_AVAILABLE: received data from the device.  This can be a result of read
    //                        or notification operations.
    private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) {
                mConnected = true;
                updateConnectionState(R.string.connected);
                invalidateOptionsMenu();
            } else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) {
                mConnected = false;
                updateConnectionState(R.string.disconnected);
                invalidateOptionsMenu();
            } else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) {
                // Show all the supported services and characteristics on the user interface.
                displayGattServices(mBluetoothLeService.getSupportedGattServices());
            }
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gatt_services_characteristics);

        ActionBar bar = getActionBar();
        bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3F51B5")));
        Window window = getWindow();
        window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
        window.setStatusBarColor(this.getResources().getColor(R.color.colorPrimaryDark));

        final Intent intent = getIntent();
        mDeviceName = intent.getStringExtra(EXTRAS_DEVICE_NAME);
        mDeviceAddress = intent.getStringExtra(EXTRAS_DEVICE_ADDRESS);

        // Sets up UI references.
        ((TextView) findViewById(R.id.device_address)).setText(mDeviceAddress);
        mConnectionState = (TextView) findViewById(R.id.connection_state);
        // is serial present?
        isSerial = (TextView) findViewById(R.id.isSerial);

        getActionBar().setTitle(mDeviceName);
        getActionBar().setDisplayHomeAsUpEnabled(true);
        Intent gattServiceIntent = new Intent(this, BluetoothLeService.class);
        bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);

        toggle1 = (ToggleButton) findViewById(R.id.toggleButton1);
        toggle1.setText(null);
        toggle1.setTextOn(null);
        toggle1.setTextOff(null);
        toggle2 = (ToggleButton) findViewById(R.id.toggleButton2);
        toggle2.setText(null);
        toggle2.setTextOn(null);
        toggle2.setTextOff(null);

        toggle1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    sendDataToBLE("BASHA1");//DEVICE1_ON);
                    toggle1.setBackgroundResource(R.drawable.light1);
                } else {
                    sendDataToBLE("BASHA2");//DEVICE1_OFF);
                    toggle1.setBackgroundResource(R.drawable.light0);
                }
            }
        });


        toggle2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    sendDataToBLE(DEVICE2_ON);
                    toggle2.setBackgroundResource(R.drawable.fan1);
                } else {
                    sendDataToBLE(DEVICE2_OFF);
                    toggle2.setBackgroundResource(R.drawable.fan0);
                }
            }
        });


    }

    void sendDataToBLE(String str) {
        Log.d(TAG, "Sending result=" + str);
        final byte[] tx = str.getBytes();
        if (mConnected) {
            characteristicTX.setValue(tx);
            mBluetoothLeService.writeCharacteristic(characteristicTX);
            mBluetoothLeService.setCharacteristicNotification(characteristicRX, true);
        }
    }


    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
        if (mBluetoothLeService != null) {
            final boolean result = mBluetoothLeService.connect(mDeviceAddress);
            Log.d(TAG, "Connect request result=" + result);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mGattUpdateReceiver);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(mServiceConnection);
        mBluetoothLeService = null;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.gatt_services, menu);
        if (mConnected) {
            menu.findItem(R.id.menu_connect).setVisible(false);
            menu.findItem(R.id.menu_disconnect).setVisible(true);
        } else {
            menu.findItem(R.id.menu_connect).setVisible(true);
            menu.findItem(R.id.menu_disconnect).setVisible(false);
        }
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_connect:
                mBluetoothLeService.connect(mDeviceAddress);
                return true;
            case R.id.menu_disconnect:
                mBluetoothLeService.disconnect();
                return true;
            case android.R.id.home:
                onBackPressed();
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private void updateConnectionState(final int resourceId) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                mConnectionState.setText(resourceId);
            }
        });
    }

    // Demonstrates how to iterate through the supported GATT Services/Characteristics.
    // In this sample, we populate the data structure that is bound to the ExpandableListView
    // on the UI.
    private void displayGattServices(List<BluetoothGattService> gattServices) {
        if (gattServices == null) return;
        String uuid = null;
        String unknownServiceString = getResources().getString(R.string.unknown_service);
        ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<HashMap<String, String>>();


        // Loops through available GATT Services.
        for (BluetoothGattService gattService : gattServices) {
            HashMap<String, String> currentServiceData = new HashMap<String, String>();
            uuid = gattService.getUuid().toString();
            currentServiceData.put(
                    LIST_NAME, SampleGattAttributes.lookup(uuid, unknownServiceString));

            // If the service exists for HM 10 Serial, say so.
            if (SampleGattAttributes.lookup(uuid, unknownServiceString) == "HM-10 Serial") {
                isSerial.setText("Yes");
            } else {
                isSerial.setText("No");
            }
            currentServiceData.put(LIST_UUID, uuid);
            gattServiceData.add(currentServiceData);

            // get characteristic when UUID matches RX/TX UUID
            characteristicTX = gattService.getCharacteristic(BluetoothLeService.UUID_HM_RX_TX);
            characteristicRX = gattService.getCharacteristic(BluetoothLeService.UUID_HM_RX_TX);


        }

    }

    private static IntentFilter makeGattUpdateIntentFilter() {
        final IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_CONNECTED);
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_DISCONNECTED);
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED);
        intentFilter.addAction(BluetoothLeService.ACTION_DATA_AVAILABLE);
        return intentFilter;
    }
}

Answer 1

the problem was that onReceive Method is called and never get the data from BroadcastReceiver so I've added to the onReceive method inside BroadcastReceiver :

 else if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action)) {
 String value = intent.getStringExtra(BluetoothLeService.EXTRA_DATA);
 if(value != null){ 
   displayData(value); Log.e("data = ",value.toString()); }
 else{ Log.e(TAG, "value = null"); } 

link for the full working code : https://github.com/Waged/BLEArduino