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!

[ThienNBK]

Hi, new update. Today I checked the debug logging again carefully and found something new. The log shows the following message:

00> [00:01:16.473,309] <wrn> bt_conn: conn 0x200026f8 failed to establish. RF noise?

Note that I didn't log this message — I think the system generated it.

[Vidar Berg]

You need to update to SDK v2.9.2 or later to narrow down the problem. Have you done that? Yes, the fact that it is only failing one some boards suggests that it may be a HW issue.

Also recommend you create a new private ticket and request a HW review of your design if you have not done this already.