openL2CAPChannel fails on iOS - same code works on macOS

[denis]

Attached is a nRF52840-DK project and an Xcode project with iOS and macOS targets.  When I run on macOS the L2CAP channel is opened.  When I run on iOS the L2CAP is not opened.  Any ideas on why this might be?  Anyone know of iOS working with nRF5 L2CAP examples?

Simple Bluetooth.zip

[denis]

If I change the PSM from 0x1001 to 0x25 then iOS does open the connection, but also issues some warnings:

2018-11-07 11:27:01.654639-0600 Simple Bluetooth iOS[13373:9843832] didOpenL2CAPChannel Optional(<CBL2CAPChannel: 0x28336c4b0 peer = <CBPeripheral: 0x280c24820, identifier = 5DEE8C89-16AF-356F-A0CA-B3C7D810E4E3, name = Firefly, state = connected>, psm = 37>) error: nil

2018-11-07 11:27:01.681656-0600 Simple Bluetooth iOS[13373:9843832] [CoreBluetooth] WARNING: Unknown error: 436

2018-11-07 11:27:01.682131-0600 Simple Bluetooth iOS[13373:9843832] [CoreBluetooth] No known channel matching peer <CBPeripheral: 0x280c24820, identifier = 5DEE8C89-16AF-356F-A0CA-B3C7D810E4E3, name = Firefly, state = connected> with psm 37

[haakonsh]

Hey Denis, 

I need to compile your project, what SDK are you using? 

Cheers,

[denis]

I'm using the latest nRF5 SDK 15.2.0.

[Juju]

Hi Denis

I was just having the same problem as you because on iOS side, I was not keeping a strong reference to 

the CBL2CAPChannel object given by:

- (void)peripheral:(CBPeripheral *)peripheral didOpenL2CAPChannel:(CBL2CAPChannel *)channel error:(NSError *)error

Now I will try to send/receive data from it...

Found the trick here: stackoverflow.com/.../52239966

[denis]

Hi Juju,

I'm keeping a strong reference, so don't think that is the issue here.  Also - works consistently with a predefined PSM, just not with the PSM I want to use.