@berndbausch suffering from similar at the moment
I need to send an audio file of some kind over a gsm module, I have a mic and a speaker connection on the gsm module, but no guidance on where to get started with making this happen.
It looks very possible and whilst it will need something from the pin to the gsm module to make it happen not sure on exactly what I need, why I need it, so will have to do some more digging.