问题:

I am developing an Android app which should subscribe to multiple BLE characteristics.

But whatever I do, I receive only the updated values from one characteristic.

Here is the code:

BluetoothGattCharacteristic characteristicVel = gatt.getService(BleDefinedUUIDs.Service.KOMMMODUL_SERVICE).getCharacteristic(BleDefinedUUIDs.Characteristic.VELOCITY);                 gatt.setCharacteristicNotification(characteristicVel, true);                 BluetoothGattDescriptor descriptorVel = characteristicVel.getDescriptor(                         BleDefinedUUIDs.Descriptor.CHAR_CLIENT_CONFIG);                 descriptorVel.setValue(BleDefinedUUIDs.Descriptor.ENABLE_NOTIFICATION_VALUE);                 gatt.writeDescriptor(descriptorVel);              BluetoothGattCharacteristic characteristicAcc = gatt.getService(BleDefinedUUIDs.Service.KOMMMODUL_SERVICE).getCharacteristic(BleDefinedUUIDs.Characteristic.ACCELERATION);             gatt.setCharacteristicNotification(characteristicAcc, true);             BluetoothGattDescriptor descriptorAcc = characteristicAcc.getDescriptor(                     BleDefinedUUIDs.Descriptor.CHAR_CLIENT_CONFIG);             descriptorAcc.setValue(BleDefinedUUIDs.Descriptor.ENABLE_NOTIFICATION_VALUE);             gatt.writeDescriptor(descriptorAcc);

Whatever I do I get only the velocity data. If I change the order of the two blocks I get acceleration only but no more velocity data.

What have I to do in order to subscribe to many characteristics at once?

Thanks in advance

Reto

回答1:

To get descriptors to write one after another, please wait for the callback from a descriptor write before starting the next one.

回答2:

For all the future readers, here is how to do it:

List<BluetoothGattCharacteristic> characteristics = GetCharacteristicsWithNotifications(gatt);  subscribeToCharacteristics(gatt);  private void subscribeToCharacteristics(BluetoothGatt gatt) {     if(characteristics.size() == 0) return;      BluetoothGattCharacteristic characteristic = notifyCharacteristics.get(0);     gatt.setCharacteristicNotification(characteristic, true);     characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);      UUID uuid = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");     BluetoothGattDescriptor descriptor = characteristic.getDescriptor(uuid);     if(descriptor != null) {         descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);         gatt.writeDescriptor(descriptor);     } }  @Override public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {     super.onDescriptorWrite(gatt, descriptor, status);      characteristics.remove(0);     subscribeToCharacteristics(gatt); }

转载请标明出处:How to subscribe to multiple BluetoothLE Characteristics with Android

文章来源: How to subscribe to multiple BluetoothLE Characteristics with Android

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