Only receive notifications from the first characteristic registered (Android only)

[leemind]

I have an ESP32 device which notifies on 2 different characteristics. I register both characteristics to notify

UniversalBle.setNotifiable(devices[deviceID]!.device!.deviceId, Uuids.mainService, Uuids.firmwareControlCharStr, BleInputProperty.notification); UniversalBle.setNotifiable(devices[deviceID]!.device!.deviceId, Uuids.mainService, Uuids.dataCharStr, BleInputProperty.notification);

and in the debug Gatt messages this appears to be ok:

D/BluetoothGatt(24436): setCharacteristicNotification() - uuid: f645686e-cee8-418b-971a-366c641544bc enable: true D/BluetoothGatt(24436): setCharacteristicNotification() - uuid: 66ca5b73-7c39-4a6b-8915-ca0621b31803 enable: true

However in my UniversalBle.onValueChanged I only ever receive notifications for the first registered characteristic. I have swapped the two lines around in the code and verified this.

On iOS it works perfectly as expected

Flutter Doctor:

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 15.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2023.2)
[✓] VS Code (version 1.88.1)
[✓] Connected device (4 available)
[✓] Network resources```

[rohitsangwan01]

@leemind i tried multiple android characteristic together in android, and getting events from all properly
can you try with another app like NrfConnect to cross check

[sonvu1969]

Ok

[rohitsangwan01]

@leemind I am still unable to reproduce this issue. I've tested various cases across different devices.

The only scenario that caused a failure for me was when attempting to subscribe to characteristics without using await or implementing a queue.

To resolve this, you need to either:

• Use await before subscribing to another characteristic, or
• Set up a queue, either globally or per device.

Without this, Android cannot handle concurrent operations, causing subsequent commands to fail. This might be the issue you're experiencing.