discoverServices throws error on iOS (only) -> PlatformException(reactive_ble_mobile.Central.(unknown context at $101e5b3c0).Failure:1

[keehoo]

DiscoverServices functionality throws exception on iOS, works well on android.

Steps to reproduce the behavior:

1. Scan for devices

2. call await flutterReactiveBle.discoverServices(device.id).then((value) { print(value); }).onError((error, stackTrace) { print(error); });

3. Observe a failure :

4. [ +77 ms] flutter: PlatformException(reactive_ble_mobile.Central.(unknown context at $101e5b3c0).Failure:1, The operation couldn’t be completed. (reactive_ble_mobile.Central.(unknown context at $101e5b3c0).Failure error 1.), {}, null)

Expected to recieve a list of DiscoveredService

Works on Android (Android 10)

// ANDROID
[  +29 ms] I/flutter ( 9929): [DiscoveredService(serviceId: 00001801-0000-1000-8000-00805f9b34fb, characteristicIds: [00002a05-0000-1000-8000-00805f9b34fb], characteristics:
[DiscoveredCharacteristic(characteristicId: 00002a05-0000-1000-8000-00805f9b34fb, serviceId: 00001801-0000-1000-8000-00805f9b34fb)], includedServices: []), DiscoveredService(serviceId:
00001800-0000-1000-8000-00805f9b34fb, characteristicIds: [00002a00-0000-1000-8000-00805f9b34fb, 00002a01-0000-1000-8000-00805f9b34fb, 00002a04-0000-1000-8000-00805f9b34fb], characteristics:
[DiscoveredCharacteristic(characteristicId: 00002a00-0000-1000-8000-00805f9b34fb, serviceId: 00001800-0000-1000-8000-00805f9b34fb), DiscoveredCharacteristic(characteristicId:
00002a01-0000-1000-8000-00805f9b34fb, serviceId: 00001800-0000-1000-8000-00805f9b34fb), DiscoveredCharacteristic(characteristicId: 00002a04-0000-1000-8000-00805f9b34fb, serviceId:
00001800-0000-1000-8000-00805f9b34fb)], includedServices: []), DiscoveredService(serviceId: 912ffff0-3d4b-11e3-a760-0002a5d5c51b, characteristicIds:
[  +61 ms] D/BluetoothGatt( 9929): onConnectionUpdated() - Device=00:22:36:11:BC:10 interval=36 latency=0 timeout=500 status=0
[+7664 ms] Application finished.

// IOS
[  +77 ms] flutter: PlatformException(reactive_ble_mobile.Central.(unknown context at $101e5b3c0).Failure:1, The operation couldn’t be completed. (reactive_ble_mobile.Central.(unknown context at
$101e5b3c0).Failure error 1.), {}, null)```

- device that works with other BLE libraries.

I'm trying to rewrite my app using this library.

[DaemonChoejur]

This issue is sort of related to #385 Please add a short delay before calling the discoverServices. Hope that helps.

[keehoo]

@DaemonChoejur - thanks for the reply. Unfortunately that didn't help.

At some point gave it 10 seconds.

 print("Discovering services");
    await Future.delayed(const Duration(seconds: 10));
    await flutterReactiveBle.discoverServices(device.id).then((value) {
      print(value);
    }).onError((error, stackTrace) {
      print(error);
    });

Ooops, I just saw I had await and then in the same statement... Let me double check.

Nope. Still the same result, with only await and with only then.

[ozzy1873]

I saw this problem when trying to discover services before connecting to the device.

[chipweinberger]

I'm hitting the same issue, but I have connected already:

iOS: 16.4.1

  Future<void> connect() async {
    _connection = _ble.connectToDevice(
      id: _device.id,
      connectionTimeout: const Duration(seconds: 10),
    );
    await _connection!.where((event) => event.connectionState == DeviceConnectionState.connected).first;
    final services = await _ble.discoverServices(_device.id.toString());
...
}

[chipweinberger]

So something interesting. I added a 3 second delay after connection, as suggestion.

It did not fix the problem, because the connection is immediately being disconnected after connection, before discoverServices is called. I'm not sure why, but my BLE peripheral makes a chime noise on disconnection so I know this is happening.

I also see this in the logs: Warning! No event channel set up to report a connection update