Android BLE无法从设备接收Gatt特征通知 [英] Android BLE can't receive Gatt Characteristic notification from device
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问题描述
当我在特征上写入值时，我试图从设备接收通知，但什么也没收到.我在特征上启用通知，然后写入值.我已经看到设备中的特征已更改其值，但是我无法获得通知.这是我的代码:
I'm trying to receive a notification from the device when I write a value on a characteristic, but I don´t receive anything. I enable the notification on the characteristic and then I write the value. I've seen that the characteristic in the device have changed its value but I can't get the notification. Here is my code:
DeviceActivity:
DeviceActivity:
public class DevicesActivity extends Activity {
private BLEService mBluetoothLeService;
private String mDeviceAddress;
private boolean mConnected = false;
private BluetoothGattCharacteristic mNotifyCharacteristic;
private final ServiceConnection mServiceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName componentName, IBinder service) {
mBluetoothLeService = ((BLEService.LocalBinder) service).getService();
if (!mBluetoothLeService.initialize()) {
finish();
}
mBluetoothLeService.context = DevicesActivity.this;
mBluetoothLeService.connect(mDeviceAddress);
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
mBluetoothLeService = null;
}
};
private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (BLEService.ACTION_GATT_CONNECTED.equals(action)) {
mConnected = true;
invalidateOptionsMenu();
} else if (BLEService.ACTION_GATT_DISCONNECTED.equals(action)) {
mConnected = false;
invalidateOptionsMenu();
} else if (BLEService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) {
List<BluetoothGattService> servicesList;
servicesList = mBluetoothLeService.getSupportedGattServices();
Iterator<BluetoothGattService> iter = servicesList.iterator();
while (iter.hasNext()) {
BluetoothGattService bService = (BluetoothGattService) iter.next();
if (bService.getUuid().toString().equals(BLEUUID.SERVICE)){
mService = bService;
}
}
} else if (BLEService.ACTION_DATA_AVAILABLE.equals(action)) {
displayData(intent.getStringExtra(BLEService.EXTRA_DATA));
}
}
};
private static final String TAG = "BLEDevice";
public static final String EXTRA_BLUETOOTH_DEVICE = "BT_DEVICE";
private BluetoothAdapter mBTAdapter;
private BluetoothDevice mDevice;
private BluetoothGatt mConnGatt;
private int mStatus;
BluetoothGattService mService;
private EditText pinTxt;
private Button cancelBtn;
private Button unlockBtn;
private Button changePinBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.activity_devices);
pinTxt = (EditText) findViewById(R.id.pin_txt);
cancelBtn = (Button) findViewById(R.id.cancel_btn);
unlockBtn = (Button) findViewById(R.id.unlock_btn);
changePinBtn = (Button) findViewById(R.id.change_pin_btn);
unlockBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String aux = pinTxt.getText().toString();
mBluetoothLeService.sendCharacteristic(aux, getBTDeviceExtra());
}
});
mDevice = getBTDeviceExtra();
mDeviceAddress = mDevice.getAddress();
if (mServiceConnection == null){
Log.v("NULL", "mServiceConnection NULL");
}
Intent gattServiceIntent = new Intent(this, BLEService.class);
if (gattServiceIntent==null){
Log.v("NULL", "mServiceConnection NULL");
}
bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);
mStatus = BluetoothProfile.STATE_DISCONNECTED;
}
private void displayData(String data) {
if (data != null) {
Toast.makeText(DevicesActivity.this, data, Toast.LENGTH_LONG);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
unbindService(mServiceConnection);
mBluetoothLeService = null;
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(mGattUpdateReceiver);
}
private static IntentFilter makeGattUpdateIntentFilter() {
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(BLEService.ACTION_GATT_CONNECTED);
intentFilter.addAction(BLEService.ACTION_GATT_DISCONNECTED);
intentFilter.addAction(BLEService.ACTION_GATT_SERVICES_DISCOVERED);
intentFilter.addAction(BLEService.ACTION_DATA_AVAILABLE);
return intentFilter;
}
@Override
protected void onResume() {
super.onResume();
registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
if (mBluetoothLeService != null) {
final boolean result = mBluetoothLeService.connect(mDeviceAddress);
}
}
private BluetoothDevice getBTDeviceExtra() {
Intent intent = getIntent();
if (intent
== null) { return null;
}
Bundle extras = intent.getExtras();
if (extras == null) {
return null;
}
BluetoothDevice aux = extras.getParcelable(EXTRA_BLUETOOTH_DEVICE);
return aux;
}
BLEService:
BLEService:
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
String intentAction;
if (newState == BluetoothProfile.STATE_CONNECTED) {
intentAction = ACTION_GATT_CONNECTED;
mConnectionState = STATE_CONNECTED;
broadcastUpdate(intentAction);
Log.i(TAG, "Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:" +
mBluetoothGatt.discoverServices());
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
intentAction = ACTION_GATT_DISCONNECTED;
mConnectionState = STATE_DISCONNECTED;
Log.i(TAG, "Disconnected from GATT server.");
broadcastUpdate(intentAction);
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
for (BluetoothGattService service : gatt.getServices()) {
if ((service == null) || (service.getUuid() == null)) {
continue;
}
if (BLEUUID.SERVICE.equalsIgnoreCase(service.getUuid().toString())) {
mService = service;
}
}
broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic,int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
broadcastUpdate(EXTRA_DATA, characteristic);
Log.i("CARAC","CARACTERISTICA LEIDA onCharacteristicRead()");
}
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt,BluetoothGattCharacteristic characteristic) {
readCharacteristic(characteristic);
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
Log.i("CARAC","CAMBIO EN CARACTERISTICA");
}
};
private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
private void broadcastUpdate(final String action,final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
if (PIN_CHARACTERISTIC.equals(characteristic.getUuid())) {
final String pin = characteristic.getStringValue(0);
intent.putExtra(EXTRA_DATA, String.valueOf(pin));
} 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));
Log.i("RECIBIDO", "RECIBIDOS DATOS");
intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
}
}
sendBroadcast(intent);
}
public class LocalBinder extends Binder {
BLEService getService() {
return BLEService.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
// After using a given device, you should make sure that BluetoothGatt.close() is called
// such that resources are cleaned up properly. In this particular example, close() is
// invoked when the UI is disconnected from the Service.
close();
return super.onUnbind(intent);
}
private final IBinder mBinder = new LocalBinder();
public boolean initialize() {
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
return false;
}
return true;
}
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
return false;
}
// Previously connected device. Try to reconnect.
if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
if (mBluetoothGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
return false;
}
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
mBluetoothDeviceAddress = address;
mConnectionState = STATE_CONNECTING;
return true;
}
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
return;
}
mBluetoothGatt.disconnect();
}
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
Log.e("CIERRE", "CONEXION CERRADA");
}
public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
return;
}
mBluetoothGatt.readCharacteristic(characteristic);
Log.i("READ", "CARACTERISTICA LEIDA");
}
public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic, boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
if (PIN_CHARACTERISTIC.equals(characteristic.getUuid())){
BluetoothGattDescriptor descriptor =
new BluetoothGattDescriptor(UUID.nameUUIDFromBytes(BLEUUID.PIN_CHARACTERISTIC_CONFIG_DESCRIPTOR.getBytes()),
BluetoothGattDescriptor.PERMISSION_WRITE_SIGNED);
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
mBluetoothGatt.writeDescriptor(descriptor);
}
}
public List<BluetoothGattService> getSupportedGattServices() {
if (mBluetoothGatt == null) return null;
return mBluetoothGatt.getServices();
}
public void sendCharacteristic(String pin, BluetoothDevice device){
byte[] pinByte = pin.getBytes();
int pinInt = Integer.valueOf(pin);
BluetoothGattCharacteristic ch = (BluetoothGattCharacteristic) mService.getCharacteristic(UUID
.fromString(BLEUUID.PIN_CHARACTERISTIC_UUID));
ch.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);
ch.setValue(pin);
Toast.makeText(context, "CARACTERISTICA ASIGNADA", Toast.LENGTH_SHORT).show();
connect(device.getAddress());
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
setCharacteristicNotification(ch, true);
if (mBluetoothGatt.writeCharacteristic(ch)) {
Toast.makeText(context, "CARACTERISTICA ESCRITA", Toast.LENGTH_SHORT).show();
}
}
}
BLEUUID
public class BLEUUID {
// CARACTERISTICA PIN
public static final String SERVICE ="0000fff0-0000-1000-8000-00805f9b34fb";
public static final String PIN_CHARACTERISTIC_UUID="0000fff9-0000-1000-8000-00805f9b34fb";
public static final String PIN_CHARACTERISTIC_CONFIG_DESCRIPTOR="0x2902";
private static HashMap<String, String> attributes = new HashMap();
static {
attributes.put(SERVICE, "Service");
attributes.put(PIN_CHARACTERISTIC_UUID, "Pin");
}
当我调试时，onCharacteristicChange()永远不会执行.
When I debug, onCharacteristicChange() never executes.
有人知道问题出在哪里
推荐答案
这是在Android上使用BLE的工作方式的一般模式:
Here is the general pattern for how things need to work with BLE on Android:
- 您尝试连接
- 您会收到一个回调，表明它已连接
- 您发现了服务
- 被告知服务被发现
- 您掌握了特色
- 对于每个特征，您都会获得描述符
- 对于描述符，您可以通过BluetoothGattDescriptor.setValue()将其设置为启用通知/指示
- 您使用BluetoothGatt.writeDescriptor()编写描述符
- 您可以使用BluetoothGatt.setCharacteristicNotification()在本地启用特征通知.没有这个，您将不会被回电.
- 您会收到有关描述符已编写的通知
- 现在您可以将数据写入特征.在将任何内容写入任何特征之前，已经完成了所有特征和描述符配置.
- You try to connect
- You get a callback indicating it is connected
- You discover services
- You are told services are discovered
- You get the characteristics
- For each characteristic you get the descriptors
- For the descriptor you set it to enable notification/indication with BluetoothGattDescriptor.setValue()
- You write the descriptor with BluetoothGatt.writeDescriptor()
- You enable notifications for the characteristic locally with BluetoothGatt.setCharacteristicNotification(). Without this you won't get called back.
- You get notification that the descriptor was written
- Now you can write data to the characteristic. All of the characteristic and descriptor configuration has do be done before anything is written to any characteristic.
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