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);
}
来源:https://stackoverflow.com/questions/38230684/how-to-subscribe-to-multiple-bluetoothle-characteristics-with-android