nRF5340 Audio DK - LE Audio CIS example not works

[ashokr.com]

Hi Team,

we are using two nRF5340 Audio DK kits to test LE Audio CIS example (unicast client & server).

kit1 nRF5340 Audio DK - act as gateway ( connected to PC/shared usb audio )

kit2 nRF5340 Audio DK - act as headset  ( earphone)

after power ON kit1 , I did not see the LED1 (blue) blinking.

I see following logs printing security failure messages on client side. kindly help on getting CIS mode working on two audio kits.

GW [00:00:00.269,348] <inf> board_version: Compatible board/HW version found: 1.0.0
GW [00:00:00.301,696] <inf> fw_info:
nRF5340 Audio nRF5340 Audio DK cpuapp
NCS base version: 3.0.2
Cmake run : Thu Jun 19 18:16:28 2025
GW [00:00:00.301,696] <inf> fw_info: ------- DEBUG BUILD -------
GW [00:00:00.301,696] <inf> fw_info: Compiled for GATEWAY device
GW [00:00:00.343,536] <inf> bt_mgmt_ctlr_cfg: Controller: SoftDevice: Version 6.0 (0x0e), Revision 8435
GW [00:00:00.343,719] <inf> bt_mgmt: Local identity addr: F4:47:0D:BD:D3:16 (random)
GW [00:00:00.343,902] <inf> audio_usb: Ready for USB host to send/receive.
GW [00:00:00.346,496] <inf> bt_mgmt_scan: Local addr: 50:29:D3:9C:DB:AA (random). May time out. Updates not printed
GW [00:00:00.346,527] <inf> bt_mgmt_scan: Scanning successfully started
GW [00:00:00.410,675] <inf> bt_mgmt_scan: Creating connection to device: 47:88:13:0E:EC:8E (random)
GW [00:00:00.511,535] <inf> bt_mgmt: Connected: 47:88:13:0E:EC:8E (random)
GW [00:00:00.511,566] <inf> main: Connection event. Num connections: 1
GW [00:00:00.553,802] <wrn> bt_mgmt: Security failed: level 1 err 9
GW [00:00:00.553,802] <wrn> bt_mgmt: Failed to disconnect -128
GW [00:00:00.554,046] <inf> bt_mgmt: Disconnected: 47:88:13:0E:EC:8E (random), reason 0x05
GW [00:00:00.554,077] <inf> main: Disconnection event. Num connections: 0
GW [00:00:00.554,077] <wrn> unicast_client: Unknown connection disconnected
GW [00:00:00.554,962] <inf> bt_mgmt_scan: Local addr: 50:29:D3:9C:DB:AA (random). May time out. Updates not printed
GW [00:00:00.554,992] <inf> bt_mgmt_scan: Scanning successfully started
GW [00:00:01.845,275] <inf> bt_mgmt_scan: Creating connection to device: 77:1B:D1:1C:67:E8 (random)
GW [00:00:01.950,073] <inf> bt_mgmt: Connected: 77:1B:D1:1C:67:E8 (random)
GW [00:00:01.950,103] <inf> main: Connection event. Num connections: 1
GW [00:00:01.992,279] <wrn> bt_mgmt: Security failed: level 1 err 9
GW [00:00:01.992,279] <wrn> bt_mgmt: Failed to disconnect -128
GW [00:00:01.992,523] <inf> bt_mgmt: Disconnected: 77:1B:D1:1C:67:E8 (random), reason 0x05
GW [00:00:01.992,553] <inf> main: Disconnection event. Num connections: 0
GW [00:00:01.992,584] <wrn> unicast_client: Unknown connection disconnected
GW [00:00:01.993,499] <inf> bt_mgmt_scan: Local addr: 50:29:D3:9C:DB:AA (random). May time out. Updates not printed
GW [00:00:01.993,499] <inf> bt_mgmt_scan: Scanning successfully started
GW [00:00:03.284,637] <inf> bt_mgmt_scan: Creating connection to device: 4D:8F:CE:E2:1A:E7 (random)
GW [00:00:03.393,066] <inf> bt_mgmt: Connected: 4D:8F:CE:E2:1A:E7 (random)
GW [00:00:03.393,096] <inf> main: Connection event. Num connections: 1
GW [00:00:03.435,272] <wrn> bt_mgmt: Security failed: level 1 err 9
GW [00:00:03.435,272] <wrn> bt_mgmt: Failed to disconnect -128
GW [00:00:03.435,546] <inf> bt_mgmt: Disconnected: 4D:8F:CE:E2:1A:E7 (random), reason 0x05
GW [00:00:03.435,577] <inf> main: Disconnection event. Num connections: 0
GW [00:00:03.435,577] <wrn> unicast_client: Unknown connection disconnected
GW [00:00:03.436,492] <inf> bt_mgmt_scan: Local addr: 50:29:D3:9C:DB:AA (random). May time out. Updates not printed

 

Thanks

Ashok R

[Edvin]

Hello Ashok,

Could it be that some old bonding data is stored in one device, and not the other? Try erasing both boards, and re-program them with the applications and see if the behavior changes. 

To erase the board, you can do this in VS Code by clicking the 3 dots next to your board in the "Connected Devices" tab, and select "Erase board"

Or you can use nrfjprog:

nrfjprog --eraseall

Or you can use nrfutil:

nrfutil device erase

Best regards,

Edvin

[ashokr.com]

Hi Edvin,

Thanks it works and solved the connection issue but now new problem i'm facing is , Audio stream received on the sever (audio jack) breaks, not clear, strucks. On TX side I see below log warnings.

when usb audio is playing (laptop) uart logs prints are not working, could be memory buffer issue?   

GW [00:02:06.965,057] <inf> unicast_client: LEFT source stream configured
GW [00:02:06.965,118] <inf> le_audio: LC3 codec config for source:
GW [00:02:06.965,118] <inf> le_audio: Frequency: 24000 Hz
GW [00:02:06.965,118] <inf> le_audio: Duration: 10000 us
GW [00:02:06.965,118] <inf> le_audio: Channel allocation: 0x1
GW [00:02:06.965,148] <inf> le_audio: Octets per frame: 60 (48000 bps)
GW [00:02:06.965,148] <inf> le_audio: Frames per SDU: 1
GW [00:02:07.724,884] <inf> unicast_client: Stream 0x20012170 started
GW [00:02:07.726,715] <inf> audio_usb: USB RX first data received.
GW [00:02:07.759,582] <wrn> audio_usb: USB TX underrun. Num: 2801
GW [00:02:07.859,588] <wrn> audio_usb: USB TX underrun. Num: 2901
GW [00:02:07.905,487] <inf> unicast_client: Stream 0x20012270 started
GW [00:02:07.915,588] <inf> audio_usb: USB TX first data sent.
GW [00:02:08.189,697] <wrn> audio_usb: Wrong length: 183
GW [00:02:21.125,000] <wrn> audio_usb: USB TX underrun. Num: 3001
GW [00:02:21.555,023] <wrn> audio_usb: USB TX underrun. Num: 3101
GW [00:02:22.005,035] <wrn> audio_usb: USB TX underrun. Num: 3201
GW [00:02:22.455,047] <wrn> audio_usb: USB TX underrun.

Thanks

Ashok r