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USB audio on VF3000-L33-AVS

Posted: Sat Apr 21, 2018 9:16 am
by sraudiogum
Hi, I'm trying to get USB audio working from a VF3000-L33-AVS dev kit. I understand that the device should just plug in and show up as USB speaker and microphone.
I flashed firmware from here - http://www.xmos.com/published/vocalfusi ... ion=latest - as it didn't seem to come with any on by default. I have tried 1i1o2_lin33_asr and 1i2o2_lin33_48khz. After both of those, I can see the device show up as speaker and microphone on my mac and a linux device - however, when trying to play sound through the output device, nothing can be heard. I also noticed that alsa mixer AND mac system preferences said there was no mixer capabilities (output controls on mac) with the output device, so I wondered if that was related?
A lot of the instructions on the site talk about building firmware, but that doesn't seem possible at the dev-kit stage, so I was left a bit confused. I guess my question is - what's the best firmware to flash on to a VF3000-L33-AVS dev kit to get USB mic and speaker working and could you give me a direct link please?
Thanks,
Steve

Re: USB audio on VF3000-L33-AVS

Posted: Mon Apr 23, 2018 2:32 pm
by infiniteimprobability
Hi, there are no volume controls enabled inside the firmware by default. It is possible but you need to consider AEC reference volume vs. coupled far-end levels for best performance.. Best to keep it as is initially.

There are a lot of builds but the ones you mentioned should both be fine. Use a 48kHz build if you need to playback music otherwise you'll loose content above 8kHz.

DOes it work OK as a mic? Is it just the output that doesn't work? Be aware that you will just hear the output on one channel..

Re: USB audio on VF3000-L33-AVS

Posted: Tue Apr 24, 2018 10:24 am
by sraudiogum
Thanks for the reply!
I flashed 1i2o2_lin33_48khz back on as I want music output. I hadn't tried the mic before, but yes, mic input does work, so just the output not working. Can you suggest anything I can do to help you help me - any logs or test I can run?
Thanks again,
Steve

Re: USB audio on VF3000-L33-AVS

Posted: Tue Apr 24, 2018 11:52 am
by infiniteimprobability
Can you suggest anything I can do to help you help me
It feels like a possible HW issue.. Can you put a scope probe on the I2S header (attached) and verify you are seeing a proper 3.072MHz BCLK, 48k LRCLK and data?

You should be seeing activity when you play audio out from the host. Basically the output path behaves like a sound card to the 3.5mm jack via the DAC