Cannot connect to BLE device from iOS

[ThienNBK]

Hi everyone,

I’m designing custom hardware for my application using the nRF54L05 MCU (v2.9.0). However, I can’t connect to the device from iOS — the connection always fails (it just keeps trying to connect; see the attached image).

I initially suspected a firmware issue, but when I run the same firmware on the nRF54L15-DK, it works stably. This leads me to believe the problem might be hardware-related.

Has anyone encountered a similar issue? Could it be caused by a hardware design flaw, or is it still possibly a software/configuration problem?

Any suggestions would be greatly appreciated.
Many thanks!

[Vidar Berg]

Hello,

Had you tried to connect to it with an Android phone also? Either way, please build your application with SDK v.2.9.2 and see if you get the same result. This release includes fixes related to errata handling for the nRF54L05 (https://docs.nordicsemi.com/bundle/ncs-2.9.2/page/nrf/releases_and_maturity/releases/release-notes-2.9.2.html#nrfx).

Best regards,

Vidar

[ThienNBK]

Thanks for your reply. However, I also want to understand what happened to me — do you have any idea?
Moreover, I prepared 5 PCBs, but only 2 of them have this issue. The others work stably.

[Vidar Berg]

There are many potential causes for connection problems, and there isn't enough information here to say what's causing it. Please update the SDK version to v2.9.2 or later and answer my question to troubleshoot this further. 

ThienNBK said:

Moreover, I prepared 5 PCBs, but only 2 of them have this issue. T

This is new information. Have you enabled debug logging on the device to see if any errors are reported?

[ThienNBK]

Hi, I have connected my device to an Android phone and got the same result.
After that, I enabled debug logging, and there were no issues — everything worked fine.
As I mentioned in my previous response, 3 out of 5 boards run stably.
I think the problem is caused by hardware, but I’ve checked the PCB carefully and couldn’t find any issues.