studio - Suscribirse a una notificación de BLE Gatt para Android.

bluetooth low energy android studio

Question

Estoy desarrollando una aplicación BLE, basada en el proyecto de ejemplo de Gatt proporcionado por google: https://developer.android.com/samples/BluetoothLeGatt/index.html . Por lo tanto, puedo enviar datos escribiendo en una característica con éxito. Ahora necesito saber cuando esta característica cambia su valor. Entiendo que necesito implementar el método setCharacteristicNotification () y el método onDescriptorWrite (). Pero no puedo hacer que esto funcione. Buscando, encontré algunas ideas al respecto: API BLE de Android: no se recibió la notificación de GATT , ¿cuáles son los pasos para recibir una notificación mediante el dispositivo Bluetooth de baja energía (BLE)? , pero todavía no tengo suerte, no entiendo cómo funciona, qué parámetro necesito definir o qué debo hacer. Alguna buena alma me puede compartir un proyecto completo que haga esto. Todo lo que necesito es visualizar el valor de la característica cuando el dispositivo BLE devuelve algunos datos.

Leí la documentación oficial de Android, pero no es tan específico al respecto. Gracias por adelantado

Estos son mis códigos:

Dispositivo

public class DeviceControlActivity extends Activity {
public static final String EXTRAS_DEVICE_NAME = "DEVICE_NAME";
public static final String EXTRAS_DEVICE_ADDRESS = "DEVICE_ADDRESS";
private TextView mConnectionState;
private TextView mDataField;
private TextView mRssiField;
private String mDeviceName;
private String mDeviceAddress;
private ExpandableListView mGattServicesList;
private BluetoothLeService mBluetoothLeService;
static ArrayList<ArrayList<BluetoothGattCharacteristic>> mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>();
private boolean mConnected = false;
private BluetoothGattCharacteristic mNotifyCharacteristic;
private BluetoothGattCharacteristic mWriteCharacteristic, mReadCharacteristic;
Button Escritor;
byte hello[] = { 0 };
private final String LIST_NAME = "NAME";
private final String LIST_UUID = "UUID";
// BluetoothGattCharacteristic characteristic;
// public BluetoothGatt mBluetoothGatt;
// 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("Unable to initialize Bluetooth");
finish();
}
// Automatically connects to the device upon successful start-up
// initialization.
mBluetoothLeService.connect(mDeviceAddress);
mBluetoothLeService.setBLEServiceCb(mDCServiceCb);
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
mBluetoothLeService = null;
}
};
// If a given GATT characteristic is selected, check for supported features.
// This sample
// demonstrates ''Read'' and ''Notify'' features. See
// http://d.android.com/reference/android/bluetooth/BluetoothGatt.html for
// the complete
// list of supported characteristic features.
private final ExpandableListView.OnChildClickListener servicesListClickListner = new ExpandableListView.OnChildClickListener() {
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
if (mGattCharacteristics != null) {
final BluetoothGattCharacteristic characteristic = mGattCharacteristics.get(groupPosition).get(childPosition);
final int charaProp = characteristic.getProperties();
if ((charaProp & BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
// If there is an active notification on a characteristic,
// clear
// it first so it doesn''t update the data field on the user
// interface.
Log.d("BluetoothGattCharacteristic has PROPERTY_READ, so send read request");
if (mNotifyCharacteristic != null) {
mBluetoothLeService.setCharacteristicNotification(mNotifyCharacteristic, true);
mNotifyCharacteristic = null;
}
mBluetoothLeService.readCharacteristic(characteristic);
/*Toast.makeText(getApplicationContext(), "Leyó Algo",
Toast.LENGTH_SHORT).show();*/
}
if ((charaProp & BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
Log.d("BluetoothGattCharacteristic has PROPERTY_NOTIFY, so send notify request");
mNotifyCharacteristic = characteristic;
mBluetoothLeService.setCharacteristicNotification(characteristic, true);
}
if (((charaProp & BluetoothGattCharacteristic.PROPERTY_WRITE) | (charaProp & BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE)) > 0) {
Log.d("BluetoothGattCharacteristic has PROPERY_WRITE | PROPERTY_WRITE_NO_RESPONSE");
mWriteCharacteristic = characteristic;
// popup an dialog to write something.
showCharactWriteDialog();
}
return true;
}
return false;
}
};
private void showCharactWriteDialog() {
DialogFragment newFrame = new BleCharacterDialogFragment();
newFrame.show(getFragmentManager(), "blewrite");
}
private void clearUI() {
mGattServicesList.setAdapter((SimpleExpandableListAdapter) null);
mDataField.setText(R.string.no_data);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gatt_services_characteristics);
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);
mGattServicesList = (ExpandableListView) findViewById(R.id.gatt_services_list);
mGattServicesList.setOnChildClickListener(servicesListClickListner);
mConnectionState = (TextView) findViewById(R.id.connection_state);
mDataField = (TextView) findViewById(R.id.data_value);
mRssiField = (TextView) findViewById(R.id.signal_rssi);
getActionBar().setTitle(mDeviceName);
getActionBar().setDisplayHomeAsUpEnabled(true);
Intent gattServiceIntent = new Intent(this, BluetoothLeService.class);
bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);
}
@Override
protected void onResume() {
super.onResume();
// registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
if (mBluetoothLeService != null) {
final boolean result = mBluetoothLeService.connect(mDeviceAddress);
Log.d("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;
}
@TargetApi(Build.VERSION_CODES.ECLAIR)
@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);
}
});
}
private void displayData(String data) {
if (data != null) {
mDataField.setText(data);
}
}
private void displayRssi(String rssi) {
if (rssi != null) {
// Log.d("-- dispaly Rssi: " + rssi);
mRssiField.setText(rssi);
}
}
private void displayRetorno(String rssi) {
if (rssi != null) {
// Log.d("-- dispaly Rssi: " + rssi);
mRssiField.setText(rssi+"Ñ");
Toast.makeText(getApplicationContext(), "SsSsSs"+"viendo", Toast.LENGTH_SHORT).show();
}
}
// 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.
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
private void displayGattServices(List<BluetoothGattService> gattServices) {
Log.d("displayGATTServices");
if (gattServices == null)
return;
String uuid = null;
String unknownServiceString = getResources().getString(R.string.unknown_service);
String unknownCharaString = getResources().getString(R.string.unknown_characteristic);
ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<HashMap<String, String>>();
ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<ArrayList<HashMap<String, String>>>();
mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>();
// 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));
currentServiceData.put(LIST_UUID, uuid);
gattServiceData.add(currentServiceData);
ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<HashMap<String, String>>();
List<BluetoothGattCharacteristic> gattCharacteristics = gattService.getCharacteristics();
ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<BluetoothGattCharacteristic>();
// Loops through available Characteristics.
for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
charas.add(gattCharacteristic);
HashMap<String, String> currentCharaData = new HashMap<String, String>();
uuid = gattCharacteristic.getUuid().toString();
currentCharaData.put(LIST_NAME, SampleGattAttributes.lookup(uuid, unknownCharaString));
currentCharaData.put(LIST_UUID, uuid);
gattCharacteristicGroupData.add(currentCharaData);
}
mGattCharacteristics.add(charas);
gattCharacteristicData.add(gattCharacteristicGroupData);
}
SimpleExpandableListAdapter gattServiceAdapter = new SimpleExpandableListAdapter(this, gattServiceData, android.R.layout.simple_expandable_list_item_2, new String[] { LIST_NAME, LIST_UUID },
new int[] { android.R.id.text1, android.R.id.text2 }, gattCharacteristicData, android.R.layout.simple_expandable_list_item_2, new String[] { LIST_NAME, LIST_UUID }, new int[] {
android.R.id.text1, android.R.id.text2 });
mGattServicesList.setAdapter(gattServiceAdapter);
final BluetoothGattCharacteristic characteristic = mGattCharacteristics.get(2).get(0);
final int charaProp = characteristic.getProperties();
mWriteCharacteristic = characteristic;
mBluetoothLeService.setCharacteristicNotification(mWriteCharacteristic, true);
if (mWriteCharacteristic != null) {
byte[] value = { (byte) 0x0D };
mWriteCharacteristic.setValue("ATZ");
Toast.makeText(getApplicationContext(), String.valueOf(mWriteCharacteristic.getStringValue(0)), Toast.LENGTH_SHORT).show();
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
boolean jo=mBluetoothLeService.mBluetoothGatt.readCharacteristic(mWriteCharacteristic);
Toast.makeText(getApplicationContext(), String.valueOf(mWriteCharacteristic.getStringValue(0)), Toast.LENGTH_SHORT).show();
/*mWriteCharacteristic.setValue("ATE0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATE0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATL0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATM0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATS0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATH0");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue("ATAT2");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);*/
/*mWriteCharacteristic.setValue("ATZ");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
mWriteCharacteristic.setValue(value);
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);*/
}
final BluetoothGattCharacteristic characteristic2 = mGattCharacteristics.get(0).get(0);
final int charaProp2 = characteristic2.getProperties();
mReadCharacteristic = characteristic2;
mBluetoothLeService.readCharacteristic(mReadCharacteristic);
}
private DCServiceCb mDCServiceCb = new DCServiceCb();
public class DCServiceCb implements BluetoothLeService.BLEServiceCallback {
@Override
public void displayRssi(final int rssi) {
runOnUiThread(new Runnable() {
@Override
public void run() {
DeviceControlActivity.this.displayRssi(String.valueOf(rssi));
}
});
}
@Override
public void displayRetorno (final int rssi) {
runOnUiThread(new Runnable() {
@Override
public void run() {
DeviceControlActivity.this.displayRetorno("algo!!!!");
}
});
}
@Override
public void displayData(final String data) {
runOnUiThread(new Runnable() {
@Override
public void run() {
DeviceControlActivity.this.displayData(data);
Toast.makeText(getApplicationContext(), data+"SsSsSs", Toast.LENGTH_SHORT).show();
}
});
}
@Override
public void notifyConnectedGATT() {
runOnUiThread(new Runnable() {
@Override
public void run() {
mConnected = true;
updateConnectionState(R.string.connected);
invalidateOptionsMenu();
}
});
}
@Override
public void notifyDisconnectedGATT() {
runOnUiThread(new Runnable() {
@Override
public void run() {
mConnected = false;
updateConnectionState(R.string.disconnected);
invalidateOptionsMenu();
clearUI();
}
});
}
@Override
public void displayGATTServices() {
Log.d("displayGATTServices.");
runOnUiThread(new Runnable() {
@Override
public void run() {
if (mBluetoothLeService != null) {
DeviceControlActivity.this.displayGattServices(mBluetoothLeService.getSupportedGattServices());
}
}
});
}
}
@SuppressLint("ValidFragment")
public class BleCharacterDialogFragment extends DialogFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.write_charact_dialog, container, false);
final EditText ed = (EditText) v.findViewById(R.id.charact_value);
Button ok = (Button) v.findViewById(R.id.dialog_confirm);
Button cancel = (Button) v.findViewById(R.id.dialog_cancel);
ok.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mWriteCharacteristic != null) {
mWriteCharacteristic.setValue("AA");
mBluetoothLeService.mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);
}
// characteristic.setValue("FF");
// characteristic.setValue(new byte[] {(byte) 0xFF});
// writeCharacteristicValue(characteristic);
//
Toast.makeText(getApplicationContext(), "Se envío el dato", Toast.LENGTH_SHORT).show();
dismiss();
return;
}
});
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dismiss();
}
});
return v;
}
}
public void writeCharacteristicValue(BluetoothGattCharacteristic characteristica) {
byte[] value = { (byte) 0xFF };
characteristica.setValue(bytesToHex(value));
boolean status = mBluetoothLeService.mBluetoothGatt.writeCharacteristic(characteristica);
}
final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
public String bytesToHex(byte[] bytes) {
char[] hexChars = new char[bytes.length * 2];
int v;
for (int j = 0; j < bytes.length; j++) {
v = bytes[j] & 0xFF;
hexChars[j * 2] = hexArray[v >>> 4];
hexChars[j * 2 + 1] = hexArray[v & 0x0F];
}
return new String(hexChars);
}
}

Servicio

@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
public class BluetoothLeService extends Service {
// private final static String TAG =
// BluetoothLeService.class.getSimpleName();
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private String mBluetoothDeviceAddress;
BluetoothGatt mBluetoothGatt;
private int mConnectionState = STATE_DISCONNECTED;
private BLEServiceCallback mBLEServiceCb = null;
private static final int STATE_DISCONNECTED = 0;
private static final int STATE_CONNECTING = 1;
private static final int STATE_CONNECTED = 2;
private static final int GATT_SUCCESS=0;
public final static UUID UUID_HEART_RATE_MEASUREMENT = UUID.fromString(SampleGattAttributes.HEART_RATE_MEASUREMENT);
private final long READING_RSSI_TASK_FREQENCY = 500;
private static final int READ_RSSI_REPEAT = 1;
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case READ_RSSI_REPEAT:
if (mBluetoothGatt != null) {
mBluetoothGatt.readRemoteRssi();
if(DeviceControlActivity.mGattCharacteristics.size()==3)
{
boolean pp=mBluetoothGatt.readCharacteristic(DeviceControlActivity.mGattCharacteristics.get(2).get(0));//
//BluetoothGattCallback.onCharacteristicRead(mBluetoothGatt, DeviceControlActivity.mGattCharacteristics.get(2).get(0), GATT_SUCCESS);
}
}
sendMessageDelayed(obtainMessage(READ_RSSI_REPEAT), READING_RSSI_TASK_FREQENCY);
break;
}
}
};
private void startReadRssi() {
if (mHandler.hasMessages(READ_RSSI_REPEAT)) {
Log.w("+++++++++ Handler already has Message: READ_RSSI_REPEAT");
}
mHandler.sendEmptyMessage(READ_RSSI_REPEAT);
}
private void stopReadRssi() {
mHandler.removeMessages(READ_RSSI_REPEAT);
}
// Implements callback methods for GATT events that the app cares about. For
// example,
// connection change and services discovered.
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
Log.d("onConnectionStateChange status = " + status + ", newState = " + newState);
if (newState == BluetoothProfile.STATE_CONNECTED) {
if (mBLEServiceCb != null) {
mBLEServiceCb.notifyConnectedGATT();
}
Log.d("Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.d("Attempting to start service discovery:" + mBluetoothGatt.discoverServices());
startReadRssi();
//si se conecta empiece a leer mi caracteritica
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
if (mBLEServiceCb != null) {
mBLEServiceCb.notifyDisconnectedGATT();
}
stopReadRssi();
Log.d("Disconnected from GATT server.");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.d("onServicesDiscovered status = " + status);
if (status == BluetoothGatt.GATT_SUCCESS) {
if (mBLEServiceCb != null) {
mBLEServiceCb.displayGATTServices();
}
} else {
Log.d("onServicesDiscovered received: " + status);
}
setCharacteristicNotification(DeviceControlActivity.mGattCharacteristics.get(2).get(0), true);//puede que sea mejor no ponerlo, pero no se
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.d("onCharacteristicRead status: " + status);
Toast.makeText(getApplicationContext(), "MMMM"+"BBB"+"SsSsSs", Toast.LENGTH_SHORT).show();
if (status == BluetoothGatt.GATT_SUCCESS) {
displayCharacteristic(characteristic);
}
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.d("------------- onCharacteristicWrite status: " + status);
// handler callback of write characteristic.
// do somethings here.
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
Log.d("onCharacteristicChanged");
Toast.makeText(getApplicationContext(), "se ejecutó el metodo de cambio en caracteristica", Toast.LENGTH_SHORT).show();
displayCharacteristic(characteristic);
}
@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
// Log.d("onReadRemoteRssi rssi = " + rssi + "; status = " +
// status);
if (mBLEServiceCb != null) {
mBLEServiceCb.displayRssi(rssi);
}
}
};
public void setBLEServiceCb(BLEServiceCallback cb) {
if (cb != null) {
mBLEServiceCb = cb;
}
}
private void displayCharacteristic(final BluetoothGattCharacteristic characteristic) {
String msg = null;
// This is special handling for the Heart Rate Measurement profile. Data
// parsing is
// carried out as per profile specifications:
// http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
int flag = characteristic.getProperties();
int format = -1;
if ((flag & 0x01) != 0) {
format = BluetoothGattCharacteristic.FORMAT_UINT16;
Log.d("Heart rate format UINT16.");
} else {
format = BluetoothGattCharacteristic.FORMAT_UINT8;
Log.d("Heart rate format UINT8.");
}
final int heartRate = characteristic.getIntValue(format, 1);
Log.d(String.format("Received heart rate: %d", heartRate));
msg = String.valueOf(heartRate);
} else {
// For all other profiles, writes the data formatted in HEX.
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(data.length);
for (byte byteChar : data)
stringBuilder.append(String.format("%02X ", byteChar));
msg = new String(data) + "/n" + stringBuilder.toString();
}
}
if (mBLEServiceCb != null) {
mBLEServiceCb.displayData(msg);
}
}
public class LocalBinder extends Binder {
BluetoothLeService getService() {
return BluetoothLeService.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
close();
return super.onUnbind(intent);
}
private final IBinder mBinder = new LocalBinder();
public boolean initialize() {
// For API level 18 and above, get a reference to BluetoothAdapter
// through
// BluetoothManager.
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
Log.e("Unable to initialize BluetoothManager.");
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e("Unable to obtain a BluetoothAdapter.");
return false;
}
return true;
}
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
Log.w("BluetoothAdapter not initialized or unspecified address.");
return false;
}
// Previously connected device. Try to reconnect.
if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress) && mBluetoothGatt != null) {
Log.d("Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
Log.w("Device not found. Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the
// autoConnect
// parameter to false.
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
Log.d("Trying to create a new connection.");
mBluetoothDeviceAddress = address;
mConnectionState = STATE_CONNECTING;
return true;
}
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w("BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.disconnect();
}
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
}
/**
* Request a read on a given {@code BluetoothGattCharacteristic}. The read
* result is reported asynchronously through the
* {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*
* @param characteristic
* The characteristic to read from.
*/
public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
Toast.makeText(getApplicationContext(), "readCharacteristic en Servicio", Toast.LENGTH_SHORT).show();
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w("BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.readCharacteristic(characteristic);
}
/**
* Requst a write on a give {@code BluetoothGattCharacteristic}. The write
* result is reported asynchronously through the
* {@code BluetoothGattCallback#onCharacteristicWrite(andorid.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*/
public void writeCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w("BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.writeCharacteristic(characteristic);
}
/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic
* Characteristic to act on.
* @param enabled
* If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic, boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w("BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, true);
// This is specific to Heart Rate Measurement.
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mBluetoothGatt.writeDescriptor(descriptor);
}
}
/**
* Retrieves a list of supported GATT services on the connected device. This
* should be invoked only after {@code BluetoothGatt#discoverServices()}
* completes successfully.
*
* @return A {@code List} of supported services.
*/
public List<BluetoothGattService> getSupportedGattServices() {
if (mBluetoothGatt == null)
return null;
return mBluetoothGatt.getServices();
}
public interface BLEServiceCallback {
public void displayRssi(int rssi);
public void displayData(String data);
public void notifyConnectedGATT();
public void notifyDisconnectedGATT();
public void displayGATTServices();
public void displayRetorno(int rssi);
}
}

Answer 1

Además de la respuesta aceptada, tuve que configurar la característica en WRITE_TYPE_DEFAULT cuando me suscribí a un periférico que se ejecuta en OS X.

characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);

Answer 2

Para recibir una notificación en Android, debe configurar la notificación de características en verdadero

gatt.setCharacteristicNotification(characteristic, true);

También debe configurar el descriptor de configuración de las características del cliente 0x2902

// 0x2902 org.bluetooth.descriptor.gatt.client_characteristic_configuration.xml
UUID uuid = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(uuid);
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
gatt.writeDescriptor(descriptor);

Una mejor API sería para setCharacteristicNotification para establecer el descriptor, pero desafortunadamente no parece funcionar de esa manera.