Hello, my name is dio.
I created an HCI UART application using nRF Connect for VS Code with NCS v3.2.4 and enabled the Channel Sounding component via the nRF Kconfig GUI (added to prj.conf).
As a result, I was able to transmit CS_SYNC packets (Channel Sounding signals) from the nRF54L15 DK and verify them using a PXA.
However, I observed different behaviors when testing with an external DUT, and I would like to clarify whether this is expected or if there is any misconfiguration on my side.
Test setup:
- nRF54L15 DK (Reflector)
Silicon Labs DUT (Initiator) - Same behavior observed even when roles are swapped
1. RX comparison for LE_CS_TEST command
Nordic (Reflector):
01 95 20 2b 01 ff 00 03 01 00 01 01 ff 08 3d 00 00 00 7f 91 91 96 28 00 00 00 ff ff 00 00 01 29 00 0d 03 15 15 15 00 85 57 b2 36 78 6e e1 a1
Silicon Labs (Initiator):
01 95 20 2b 01 ff 00 03 00 00 01 01 ff 08 3d 00 00 00 7f 91 91 96 28 00 00 00 ff ff 00 00 01 29 00 0d 03 15 15 15 00 85 57 b2 36 78 6e e1 a1
Common behavior:
Both DUTs respond successfully to the LE_CS_TEST command with:
04 0E 04 01 95 20 00
Difference:
- When the Reflector is prepared first and the Initiator starts transmitting:
- Silicon Labs DUT responds with LE_CS_Subevent_Result event
- Nordic DUT shows no additional response
2. RX behavior for LE_CS_TEST_END command
Command:
01 96 20 00
Nordic:
- Responds with HCI_Command_Status (0x0F) →
0x0C (Command Disallowed) - No LE_CS_TEST_END_COMPLETE (0x3E) event
Silicon Labs:
- Responds with HCI_Command_Status (0x0F) →
0x00 (Success) - Followed by LE_CS_TEST_END_COMPLETE (0x3E) →
0x00 (Success)
Question
Based on the Bluetooth specification, it seems that the Nordic DUT behavior differs from the expected response (especially for LE_CS_TEST_END and missing LE_CS_Subevent_Result).
Could you please advise:
- is there any configuration (Kconfig / HCI / role setup) that I might have missed?
Any guidance would be greatly appreciated.
Thank you.
