LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

RE: LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

Edvin — Thu, 12 Sep 2024 20:53:07 GMT

Hello,

I am not sure it is possible to adjust it on the HW codec. That is not how I interpreted the feedback from our LE Audio team. Did you get to look into items 2 and 3?

Best regards,

Edvin

RE: LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

similingus — Thu, 05 Sep 2024 23:47:18 GMT

Hi Edvin,

Sorry for the delayed reply.

Regarding item 1, should I try adjust the ACLK value for my HW codec? If so, could you advise on how to find an appropriate clock frequency?

In the meantime, I will also look into items 2 and 3.

Best Regards,

Miho

RE: LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

Edvin — Fri, 30 Aug 2024 08:58:17 GMT

Hello,

I reached out to our Audio team, and they said:

1: The ACLK of a receiving nRF5340 is adjusted ever so slightly to keep playback in sync. It could be that the DA7212 does not like these subtle changes.

2: Try connect his custom HW to the codec (CS47L63) on an audio DK and see if the same thing happens. - Or try some other HW codec for that matter to definitely see if this is a FW or HW issue.

3: It would also be useful to have a look at the signal with a logic analyzer, which can decode the audio stream. Run a pure sine wave through and check the signal integrity.

Best regards,

Edvin

RE: LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

similingus — Fri, 30 Aug 2024 00:41:17 GMT

Hi Edvin,

Thank you for your response.

It does not occur when using an Audio DK.

For the HW codec, I’m using DA7212. The codec has its own sample rate setting register and supports common sample rates, including 16k, 24k 48k Hz, but changing it did not affect the observed trend of what combination produces the noise. I’m not sure about how it relates to the AUDIO_SYSTEM_SAMPLE_RATE and the LC3 codec’s sample rate from the HW codec’s datasheet.

Best,

Miho

RE: LE Audio Codec Sample Rate Configuration Issue with nRF5340-Based Hardware

Edvin — Thu, 29 Aug 2024 12:19:11 GMT

Hello,

Does this issue only occur for the custom HW? Or does it happen on the Audio DK as well? Just trying to figure out whether it could be a HW or SW issue. And how about the HW codec on the custom board? Does it support the combination that you are trying to use?

Best regards,

Edvin