Cannot connect to BLE device from iOS

RE: Cannot connect to BLE device from iOS

Vidar Berg — Fri, 04 Jul 2025 07:53:58 GMT

Good to hear you were able to identify the root cause, thanks for the update. It's still important to update to SDK 2.9.2 or later before going to production to avoid potential issues related to missing errata handling.

RE: Cannot connect to BLE device from iOS

ThienNBK — Fri, 04 Jul 2025 07:49:37 GMT

Hi, quick update.

I’ve found the root cause of the issue — it was due to a hardware mistake.

RE: Cannot connect to BLE device from iOS

Vidar Berg — Thu, 03 Jul 2025 10:14:51 GMT

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.

RE: Cannot connect to BLE device from iOS

ThienNBK — Thu, 03 Jul 2025 03:46:33 GMT

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.

RE: Cannot connect to BLE device from iOS

ThienNBK — Wed, 02 Jul 2025 09:55:02 GMT

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.

RE: Cannot connect to BLE device from iOS

Vidar Berg — Wed, 02 Jul 2025 06:44:07 GMT

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.

[quote user="ThienNBK"]Moreover, I prepared 5 PCBs, but only 2 of them have this issue. T[/quote]

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

RE: Cannot connect to BLE device from iOS

ThienNBK — Wed, 02 Jul 2025 06:31:56 GMT

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.

RE: Cannot connect to BLE device from iOS

Vidar Berg — Wed, 02 Jul 2025 06:14:59 GMT

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