USB cannot be used as an audio source for nRF5340 Audio on mac

[Paveletu]

Hi support team, I hope you're well

I cannot test nRF5340 audio sample using MacBook as a sound source due to an unknown USB issue.

When I run a sample in BIS mode and select "nRF5340 USB Audio" as the sound output device, after a short connection with a headset the board turns red and stops any transmission.

When I run a sample in CIS mode, I can hear a sound output from two connected "headset" devices, but the playback speed is extremely slow... Around 3 times slower than it should be. It actually slows down my MacBook play speed (you can see seconds in Spotify increasing slower, as well as YouTube videos barely playing).

It looks like an USB configuration issue to me. Is there anything I should change in order to make it work on MacOS? Couldn't find anything on USB configuration in the docs.

MacOS version: Monterey, 12.5.1

I didn't find UART Logs of the crash particularly useful, but here it is:

<wrn> bt_hci_core: opcode 0x2061 status 0x0c
GW [00:00:58.869,689] <wrn> audio_system: Failed to get last filled block
GW [00:00:58.869,689] <err> os: ***** BUS FAULT *****
GW [00:00:58.869,689] <err> os: Precise data bus error
GW [00:00:58.869,689] <err> os: BFAR Address: 0x713d9
GW [00:00:58.869,720] <err> os: r0/a1: 0x20000238 r1/a2: 0x2000ee34 r2/a3: 0x20003f3c
GW [00:00:58.869,720] <err> os: r3/a4: 0x000713d9 r12/ip: 0x00000000 r14/lr: 0x000445b1
GW [00:00:58.869,720] <err> os: xpsr: 0x21100000
GW [00:00:58.869,750] <err> os: s[ 0]: 0x00000000 s[ 1]: 0x00000000 s[ 2]: 0x00000000 s[ 3]: 0x00000000
GW [00:00:58.869,750] <err> os: s[ 4]: 0x00000000 s[ 5]: 0x00000000 s[ 6]: 0x00000000 s[ 7]: 0x00000000
GW [00:00:58.869,750] <err> os: s[ 8]: 0x00000000 s[ 9]: 0x00000000 s[10]: 0x00000000 s[11]: 0x00000000
GW [00:00:58.869,781] <err> os: s[12]: 0x00000000 s[13]: 0x00000000 s[14]: 0x00000000 s[15]: 0x00000000
GW [00:00:58.869,781] <err> os: fpscr: 0x2000eea8
GW [00:00:58.869,781] <err> os: Faulting instruction address (r15/pc): 0x000445b8
GW [00:00:58.869,812] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
GW [00:00:58.869,812] <err> os: Current thread: 0x20001750 (ENCODER)
GW [00:00:58.869,812] <err> error_handler: Caught system error -- reason 0. Entering infinite loop

Many thanks,
Warm Regards,
Pavel

[Paveletu]

A little update: I've just tested gateway using Android as an USB audio source and it works   

So the issue is MacBook specific.

Thank you

[Paveletu]

I switched over to I2S and it works perfectly well, so it's not an issue for me anymore. Feel free to delete the case or leave it as a bug report

Thank you,
Warm regards,
Pavel

[ovrebekk]

Hi Pavel

Good to hear you found a solution. I will leave the case if you don't mind, it could be helpful to others with the same problem

Best regards
Torbjørn

[Hejdern]

Hi Torbjørn!

I also had exactly the problems as described above on a macbook air with macOS 12.4. I tried the nrf connect 2.2.0-rc1 sdk and it changes into one second bursts of partly distorted audio coming through when running the CIS mode. Any news on this or work done in the upcoming release of the SDK?

Best regards,

Henrik

[ovrebekk]

Hi Henrik

We haven't investigated this issue further unfortunately. The audio team will do some testing on Mac and see if they can get to the bottom of it, but I can't promise an immediate fix to the issue. 

I will provide an update on their progress next week. 

Best regards
Torbjørn