Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

BLEguy — Fri, 15 May 2020 21:25:24 GMT

Did anyone find a solution to this issue which does not require forgetting the device in the phone settings?

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

Joakim Jakobsen — Wed, 29 Apr 2020 10:10:40 GMT

Thank for the additional information.

I will look further into this and see what I can find. As of now my best suggestion is to erase the bonding information on the phone, but I'll see what I can find.

Best regards,
Joakim

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

AlekseyAK — Tue, 28 Apr 2020 18:16:33 GMT

Hi,

I would like to clarify then the behavior on repairing. Here you can see the video where the repairing of iOS 12 with the device is performed without the error. And it was so for all iOS devices until we started using iOS 13.4.

https://drive.google.com/file/d/1OliEdERNnxb0x7bNWYp02kTTrfxocES2/view?usp=sharing

If requirement to forget the device on iPhone before pairing is in Bluetooth security specification, does that mean that before iOS 13.4 Apple ignored that requirement?

Also, we don't have this problem with all Android OS versions, repairing performed as expected.

I think it is new feature for iOS 13.4 and, probably, we will not find the acceptable solution, just to ask the user to forget the device in the settings. If you have an idea how to solve it, it would be great.

Thank you in advance, Aleksey.

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

Joakim Jakobsen — Tue, 28 Apr 2020 08:05:41 GMT

Hi again.

Did some research and talked to some colleagues about this.

I still stand by my statements below, that the phone will not and should not connect and re-pair automatically if the bonding information is deleted on the nRF. This is implemented as a security feature.

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

AlekseyAK — Fri, 24 Apr 2020 06:36:36 GMT

Hi Joakim,

We tested again the repairing with the device from iPhone with iOS 13.3.1 and it works fine. The iPhone updated its bonding information.

Starting iOS 13.4 something changed and the phone after failed connection does not restart the repairing process. I checked this with the SDK 16 version, the issue is reproduced.

Asking the user to delete the bonded device in the settings is not good experience for him. We need this issue fixed or may be at least some workaround.

Can you please help us solve this?

Regards, Aleksey.

RE: Bonded phone with iOS 13.4 unable to connect to the nRF52 with deleted bonding information

Joakim Jakobsen — Thu, 23 Apr 2020 12:30:32 GMT

Hi.

What you are seeing is the expected behavior here. If the bond information is erased on the nRF and the peer manager doens't have a stored bond for the phone, it will decline the connection.

You would need to erase the bond information on the phone as well in order to reconnect. I tested with an iOS device on iOS 13.3 and I'm seeing the same as you.

A workaround could be to change the address on the device, as that would make the device appear as a new device on the phone, but in my opinion that seems to be just as much work as simply deleting the bond information on the phone side.

Note; You can set allow_repair = true. This will allow you to repair the phone if the bond information is deleted on only the phone and not the nRF device. However, this will not help for the case you described above.

Best regards,
Joakim