USB Audio Feedback

[Andrew]

How is USB audio feedback implemented on the NRF52840?

[Sigurd]

Hi,

It uses a headphones audio class and a microphone audio class. See this link.

[Andrew]

That is, are you using explicit (feedback endpoint) or implicit feedback?

Feedback for Asynchronous Output Streams:  https://developer.apple.com/library/archive/technotes/tn2274/_index.html

3.7.2.2 Isochronous Synch Endpoint:  www.usb.org/.../audio10.pdf

[Sigurd]

Andrew said:

are you using explicit (feedback endpoint) or implicit feedback?

I don't think that is used. See the discussion in this post.

[Andrew]

So it looks like you just send data back to the computer at exactly the rate you receive it from the computer thus sample rate conversions must be handled by the NRF52840.