Hello!
Is it possible to change GPIOs states depending on audio file frequency and resolution? It could be used to connect displays for showing frequency and resolution. It would be nice feature.
Thanks.
Yep, you can do it via a plugin
Thank you for replies.
Does a suitable plugin exist? If it does not, please advise some links / examples of how plugins are created.
Thanks.
I don’t believe so - but you could look again in Volumio Plugins Collection
As for writing a plugin - the docs might be a bit sparse, but it is a good start Writing A Plugin - Volumio Documentation
You could also peek into some other plugins from the GitHub - volumio/volumio-plugins repository for inspiration 
Thank you.