How is the period for channel sounding results determined?

RE: How is the period for channel sounding results determined?

witc — Sat, 04 Oct 2025 22:13:32 GMT

Hi,

The mystery of slower response when getting new CS data in my code compared to the original is solved.
I had different connection parameters for the BLE link – that was the whole reason.

I used:

.conn_param = BT_LE_CONN_PARAM(80, 120, 1, 100), // 50-75 ms interval, slave latency 1, timeout 1 s

The original uses:

.conn_param = BT_LE_CONN_PARAM_DEFAULT

RE: How is the period for channel sounding results determined?

Elfving — Mon, 08 Sep 2025 08:18:11 GMT

Hi again,

[quote user="witc"]I am using VSCode - creating app from sample - see the picture. I am using ncs 3.1.0. Or do you suggest using a different example? Did you mean github nrfconnect/sdk-nrf?
[/quote]

No those are the right ones, which you can tell by them having nrf in the path names. Those are made directly from nordic, with nRFs in mind. There are other ones under 'zephyr' that might also be made by nordic, and work for nordic devices, but might not be completely supported or tested.

So as this seemingly works in the default samples it might be an idea to slowly introduce your own code to see where something ends up delaying the measurements. Though I am surprised that anything would make a difference here besides longer BLE related tasks.

Regards,

Elfving

RE: How is the period for channel sounding results determined?

Elfving — Fri, 05 Sep 2025 11:35:08 GMT

Sorry about the wait Jan

Unfortunately I have to get back to you on this next week.

Regards,

Elfving

RE: How is the period for channel sounding results determined?

witc — Thu, 04 Sep 2025 20:11:07 GMT

Hi Elfving do you have any suggestion for me?

Thank you.

RE: How is the period for channel sounding results determined?

witc — Tue, 02 Sep 2025 08:33:57 GMT

I am using VSCode - creating app from sample - see the picture. I am using ncs 3.1.0. Or do you suggest using a different example? Did you mean github nrfconnect/sdk-nrf?
https://github.com/nrfconnect/sdk-nrf/tree/main/samples/bluetooth/channel_sounding_ras_initiator

[quote userid="103347" url="~/f/nordic-q-a/123989/how-is-the-period-for-channel-sounding-results-determined/547411"]Could you check if you do see this in the default samples as well?[/quote]

Default samples: When I edit - replace in the main k_sleep(K_MSEC(5000)) by a semaphor - that signals the new ranging data are ready - I get it (new distance measurement) every 250 ms

RE: How is the period for channel sounding results determined?

Elfving — Tue, 02 Sep 2025 08:21:55 GMT

That might be an idea, though let's not go to that step yet. Could you check if you do see this in the default samples as well?

And what samples are you referring to here? The ones from the NRF repo, or the zephyr ones?

Regards,

Elfving

RE: How is the period for channel sounding results determined?

witc — Tue, 02 Sep 2025 06:32:51 GMT

Hello, right now I really do not know what could be causing it - from BLE I only use channel sounding - as it is in the ras initiator example. I will probably have to make the whole project again - start from the ras example and slowly add my code to it.

RE: How is the period for channel sounding results determined?

Elfving — Fri, 29 Aug 2025 14:00:23 GMT

Hello,

I know at least that previous versions of CS (not sure if this has been addressed in 3.1) where a bit vulnerable to scheduling conflicts - so even though you might be doing a lot, if you had some BLE activity at the wrong time it might be enough to block something that SDC would need to do a CS measurement. Though I find it odd that you get regular measurements every 750ms if that was the case. Is the other minimal actions you are doing the nRF semi-regular as well? Are you seeing anything on the logs, or on the thread viewer in VSC? Could be that there is something blocking that is showing up there.

Regards,

Elfving