Small inconsistency between iOS and Android with short/long UUID

[xvrh]

Full disclosure: I don't really understand what I'm talking about :-) I'm just reporting this in case it helps someone.

Describe the bug
I noticed a small difference between Android and iOS when registering a characteristic for Notification (subscribeToCharacteristic).

My device "somehow" uses "short UUID" (16 bits) but I was using the long form (128bits) in my code (QualifiedCharacteristic).
It works for Read and Write on both Android and iOS. But for "Subscribe" it only works for Android.

On iOS I had no error but I never received the data.

With the short Uuid, the notification worked on both platform.

Expected behavior
It should work the same on both Android and iOS. The iOS code should probably map the short Uuid (sent by the device?) to the long form registered on the phone?

Smartphone / tablet

• Device: iPhone 11 and Moto G5
• OS: iOS 13, Android 8.1
• Package version: 2.2.0

Peripheral device

• Vendor, model: ESP32
• Does it run a custom firmware / software: custom firmware based on ESP-IDF v4

[werediver]

@xvrh I imagine it wasn't easy to figure this out, thank you for sharing your findings.

The library doesn't do any transformations on service or characteristic IDs and at the moment I am not sure there is a strict rule of mapping short IDs to long or vice versa that would consistently work in all cases with all devices.

I'm afraid, your solution is a solution for a particular kind of devices and may not work with others. If you have reasons to think otherwise, I'd appreciate if you provide your references.

[xvrh]

Hi Raman, Thanks for the answer.

What surprise me, is that it worked with the plugin "flutter_blue".
I will try to dig into this a bit to understand where the data is lost.

[remonh87]

@xvrh any luck on your investigation why the data is lost?

[xvrh]

@remonh87 sorry, not yet.
I will close this issue until I have more concrete information to report :-)

Thanks.

[LiangHuangBC]

Any update on this issue? I have same issue, subscribeToCharacteristic is only working on android, there is no data on IOS. Not sure what you mean by shot UUID or long. Anyway to pass this around?

@remonh87 sorry, not yet. I will close this issue until I have more concrete information to report :-)

Thanks.