iOS Question iPhone X not connecting to BLE devices?

[TnP]

Hi All,
I had a customer state that his iPhone X could not connect to our BLE data logger. I too have been able to confirm that it cannot connect on the X that I have borrowed.

Loading the BLE Example app, I tell the phone to connect to a device and in the logs I get:

Discovering Services

Then after approximately 30 seconds (which is the timeout for our Bluetooth device), it disconnects. with this:

Disconnected: <B4IExceptionWrapper: Error Domain=CBErrorDomain Code=0 "Unknown error." UserInfo={NSLocalizedDescription=Unknown error.}>

Which I assume is the library getting an unexpected disconnection from the device.
So essentially, it looks like the connection is being made (our data logger connection LED starts flashing from the moment I tell it to connect), but the 'Manager_Connected' Event isn't being fired for some reason.

Any ideas on how to fix this?

Thanks,
Terry

EDIT: After some testing and tinkering it does work _sometimes_ if I power reset the BLE device, however, when it does work, notifications do not seem to be enabling . There is something very broken with iPhone X and BLE... Is there a way to check if notifications are indeed enabled?

 

[Erel]

Don't you see a "Error discovering services: <error here>" message?

There should also be a log message about the notification state changed.

Worth testing with a BLE app from the app store.

 

[TnP]

Hi Erel, no I don't get any error messages, nor do I get notification confirmations in the log, which concerns me.
I tried Lightblue Explorer and nRF Connect and they display similar results. Sometimes it connects, mostly after a power reset. I'm not sure what's going on.

 

[Erel]

Have you tried to restart the device?

 

[TnP]

I did, although I will try again today. We use a Texas Instruments chipset on our logger and there are several threads on their development forums with users having the same issues, so I suspect it may be more to do with the bluetooth stack in firmware and BLE5 enabled phones (not limited to iOS I understand).
I'll report back if I find out any more ASAP
Thanks Erel

 

[TnP]

Just an update:
We allocated more RAM to the heap in our datalogger RTOS and it seems to solve the issues with iPhone X (and it also affects iPhone 8's aswell).
Apparently, iOS demands almost twice as much RAM as Android on these TI chipsets.

Anyway, just a heads-up for anyone that comes across this issue in the future.
@Erel : No problems with B4i, keep up the great work