Use nRF54L15DK PCA10156 to test Bluetooth Channel Sounding

[Tovms zhangsan]

I'm use latest ncs source code and nRF54L15DK PCA10156 to test Bluetooth Channel Sounding, but i'm find the result not very accurate, and also echo such like warnings:

ter. (peer: 3329, local: 3330)
[2025-06-10 14:39:21.176] W: Mismatch of local and peer step mode 1 != 2
[2025-06-10 14:39:21.421] E: Tried to parse empty step data.
[2025-06-10 14:39:23.284] I: Dropped subevent results. Waiting for ranging data from peer.
[2025-06-10 14:39:23.373] I: Ranging data dropped as peer ranging counter doesn't match local ranging data counter. (peer: 3339, local: 3338)
[2025-06-10 14:39:24.309] I: Dropped subevent results. Waiting for ranging data from peer.
[2025-06-10 14:39:24.808] I: Dropped subevent results. Waiting for ranging data from peer.
[2025-06-10 14:39:24.885] I: Distance estimates on antenna path 0: ifft: 0.530323, phase_slope: 1.803744, rtt: 1.178596
[2025-06-10 14:39:24.893] I: Sleeping for a few seconds...
[2025-06-10 14:39:25.024] I: Ranging data dropped as peer ranging counter doesn't match local ranging data counter. (peer: 3345, local: 3344)

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[Elfving]

Hello,

I am sorry to hear that. So you are using the latest tagged version of the nordic samples (ie. this and this, don't confuse them with the one directly from Zephyr)? Or are you using the main branch?

accurate

When it comes to accuracy it is worth noting that these samples aren't made to demonstrate the best accuracy you can find, but how to get eg. the I/Q values from which you can get the distance. You could always create your own algorithm for the rest, or purchase a third party one. Though with that said, how bad is it? I would recommend looking at IFFT for shorter distances and RTT for longer ones. 

If you wonder about what sort of accuracy you should be able to achieve with BT Channel Sounding I would recommend having a look at this older webinar for the nordic distance toolbox (which is a proprietary older solution we have available for nRF52/53). It is based on a bit of the same technology as channel sounding, so the results should be similar but a bit better for channel sounding.

and also echo such like warnings:

Are these default unmodified samples? It looks to me as if one of them has modified its step mode, and there is a certain mismatch there.

Regards,

Elfving