Notify not working on Android

[burnhamd]

Describe the bug
When calling the notifyCharacteristic, the onCharacteristicChanged never firing. I am getting a value for the read. And I have checked that the device indeed does support notifications using the LightBlue Application on IOS.

To Reproduce
Steps to reproduce the behavior:

1. Connect to the device using blueFalcon.connect(bluetoothPeripheral, true)
2. Wait until didDiscoverServices Returns
3. Search through service to find the characteristic I want to nofify4.
4. Call notifyCharacteristic on the returned characteristic

char = service.characteristics.first { it.name == TESS5600_DATA_CHAR.lowercase() } bluetoothService.characteristicDelegate = this bluetoothService.notifyCharacteristic(bluetoothPeripheral, char!!, true)

Expected behavior
Expecting the onCharacteristicChanged to fire

Smartphone

• Device: Samsung Tablet
• OS: Android API 31

[Reedyuk]

Can you try the same thing using lightblue on Android(as you did for ios)? this rules out any reason it could be an android thing.

I would also suggest, after you request 'notify characteristic', can you then perform a single read after this, then wait to see if it updates?

[burnhamd]

For some reason light blue is crashing on this device on startup. Will see if I can fix that and test.

If I do a read after notify, then I get no read result either.

[burnhamd]

Just confirmed that when I subscribe using the light blue app the notifications are received from the peripheral.

[burnhamd]

I think the issue is here:
it.characteristic.descriptors.forEach { descriptor -> descriptor.value = descriptorValue gatt.writeDescriptor(descriptor) }

Here it is iterating through all descriptors and attempting to write an enable notification to it. But I have additional descriptor. Instead I think it should just set the notify descriptor "00002902-0000-1000-8000-00805f9b34fb"

[leonardovallem]

Hello you all! Any updates on this?

I'm having the exact same issue. Works on iOS, but on Android it doesn't. It does works sometimes, but most of times it doesn't. onCharacteristicChanged is not being called.

Any ideas?

Thanks in advance.

[Reedyuk]

I havent had chance to look into it. I also don't have the exact devices and setup to reproduce so it would be difficult for me. I am happy for anyone to produce a solution in a PR and i can review it.

[Reedyuk]

i have found that when you do indicate and notify it seems to be working, @leonardovallem can you confirm the same?

[leonardovallem]

i have found that when you do indicate and notify it seems to be working, @leonardovallem can you confirm the same?

for me, that worked. i had issues when trying to notify multiple characteristics, but soon solved by better managing my coroutine scopes

[Reedyuk]

Hmm, i need to look into it further but it could be to do with the characteristic properties stuff we do when we notify