Audio output?

[thefinn93]

I'm interested in using gokrazy to make audio come out of my raspberry pi. Is that something anyone has done before? I'm not seeing anything in the documentation or anywhere else online. My goal is to make a simple internet radio playback device.

[damdo]

Hey @thefinn93, that sounds like an interesting project!
Anisse worked on something vaguely similar (playback of audio on gokrazy) called beatbox.
You can see it here: https://github.com/anisse/beatbox

[thefinn93]

awesome, this is exactly the kind of starting point I was looking for! Based on a little bit of poking around, it uses a custom kernel with some magic to enable audio support, then a go library to interface with it.

[thefinn93]

following up on this: I'd like to avoid using a custom kernel if possible, and it seems like I can at least do the config.txt update if I add this to config.json:

    "BootloaderExtraLines": ["dtparam=audio=on"]

however, I'm not seeing a way to tweak the configAddendum which seems to be the other part of beatbox's custom kernel modifications. Is that possible? or will I also have to maintain a custom kernel

[stapelberg]

There is no way to change the kernel configuration at instance-build-time (this would involve building the kernel on-demand).

You can however suggest the needed changes as pull request for https://github.com/gokrazy/kernel, and as long as they don’t break anything else, we can merge it.

[thefinn93]

That sounds great! I have opened a PR.

Just noting for people interested in this in the future: Anisse's alsa library hard-codes the audio output device to one that didn't work for me (I'm guessing it's the HDMI audio output). I had to fork the library to allow specifying the output device, and it worked. I'll try to come back here and post my final results when I have something reasonably workable.