Channel Sounding example with swapped GAP roles

[nychyporuk]

I am working with the connected_cs examples on the nRF54L15 DK and trying to swap the GAP roles.
In my case:

• Initiator = GAP Peripheral

• Reflector = GAP Central

However, when I attempt this setup, I cannot start CS Security on the Initiator.

Here is the console output:
*** Booting nRF Connect SDK v3.0.2-89ba1294ac9b ***
*** Using Zephyr OS v4.0.99-783b8ae1b7a9 ***
Starting Channel Sounding Demo (Initiator)
Connected to CE:16:77:E3:B5:9A (random) (err 0x00)
MTU exchange success (247)
Security changed to level 2.
CS capability exchange completed.
CS config creation complete. ID: 0
Failed to start CS Security (err -13)

I did not find any explicit dependency in the documentation that ties the CS Security procedure to the GAP Central role, so theoretically, this configuration should work.

Question:

• Is there an internal limitation in the stack that prevents CS Security from starting when the Initiator is a GAP Peripheral?

• If not, could you point me in the right direction to get this configuration working?

I have attached the modified examples
channel_sounding.zip

[Edvin]

Hello,

Sorry for the late reply.

No, there is no requirement that the initiator needs to be the central or peripheral. I have seen it being done before, but I tried all day yesterday, and ended up with the same result as you. I will continue to investigate, and get back to you.

Best regards,

Edvin