Characteristic 0003cdd1-0000-1000-8000-00805f9b0131 notification change failed: The attribute could not be found.

[honbaa]

I use "monitorCharacteristicForDevice" method to receive notification from device. but error occurs as follows: 'Characteristic 0003cdd1-0000-1000-8000-00805f9b0131 notification change failed: The attribute could not be found.'

But the android app is ok, the error happened on iOS.

I don't know why this happened. Does anyone know ?

[honbaa]

I have found that this error described at https://github.com/Polidea/react-native-ble-plx/blob/master/ErrorMapping.md#error-mapping-for-react-native-ble-plx as follows:

characteristicNotifyChangeFailed(Characteristic, Error?) | Notify change | ???

I can't understand the reason really. Any ideas?

[honbaa]

@corymsmith @iegik @literator

[iegik]

Does your characteristic has a PROPERTY_NOTIFY? I think that your characteristic (0003cdd1-0000-1000-8000-00805f9b0131) does not have a Client Characteristic Config descriptor

• answered by @dariuszseweryn in https://github.com/Polidea/RxAndroidBle/issues/202

[Cierpliwy]

@honbaa Please reopen if needed.

[AntonioAlfrz]

Hello,

before opening a new issue I would like to ask first because I think I have a similar problem. I am facing the error: "Cannot find client characteristic config descriptor (code 2) with characteristic UUID 1ed9e2c0-266f-11e6-850b-0002a5d5c51B" (Error code 403) when trying to monitor a characteristic wiht the function monitorCharacteristicForService, although the characteristic is notifiable.

I have been able to subscribe to changes using other libraries.

Thank you.

[dariuszseweryn]

@AntonioAlfrz I am guessing you have tested on Android and that you are trying to monitor characteristic changes on some device that violates Bluetooth Spec by not having a Command Characteristic Configuration Descriptor under a characteristic that has a Notify property?

[AntonioAlfrz]

Yes, Android 6.0.1 and the device is bosch XDK

[dariuszseweryn]

I have just checked my old code for XDK interactions. It indeed does not have a proper CCC descriptor attached to notification characteristics. As for Today the newest version of the library 0.9.0 does not handle this case. You would need to revert to 0.8.0 which in turn does not correctly cancel monitoring of characteristics that do have CCC descriptor

[yashkmochi]

It can happen , if your characteristic is not notifying or indicating. Or, your characteristic might not have a Client Characteristic Config descriptor which can cause the error. If that is the case you could use function RxBleConnection.setupNotification(UUID, NotificationSetupMode.COMPAT) as a workaround. in this location ('../node_modules/react-native-ble-plx/android/src/main/java/com/polidea/reactnativeble/BleModule.java')

[Andy4ward]

@yashkmochi how do you access that function from javascript?

I've been chasing around the package to see if it's possible but coming up empty

[yashkmochi]

@Andy4ward I am not using that function direclty from javascript. It is internally being used while subscribing to specific characteristic using ble-plx.

[dariuszseweryn]

The above mentioned PR has been merged Today and there is version 1.0.2 available that should address your needs,

Best Regards

[asurare]

I had a issue pretty similar, but on iOS. I had to modify the swift sources in react-native-ble-plx⁩/ios⁩/RxBluetoothKit/Peripheral.swift⁩ with the following changes in the setNotifyValue line 326, and commenting the throw BluetoothError :

 let observable = peripheral
            .rx_didUpdateNotificationStateForCharacteristic
            .filter { $0.0 == characteristic.characteristic }
            .take(1)
            .map { (_, error) -> Characteristic in
                if let error = error {
                    // throw BluetoothError.characteristicNotifyChangeFailed(characteristic, error)
                }
                return characteristic
            }

@dariuszseweryn Would you have a better way to achieve this ?

[packetstracer]

@asurare same issue happening to me on iOS, check the bug I opened if you want to get more info.

https://github.com/Polidea/react-native-ble-plx/issues/468

What bluetooth peripheral are you trying to connect from iOS? I'm using an ESP32 (Arduino compatible) device.

[asurare]

@packetstracer The url behind your link is broken ^^