That's great that you got TouchOSC working to control parameters. Pretty cool, eh?
So, yes, given the current code, it is expected that MIDI learned events from external controllers aren't reflected on the pi-Stomp LCD. But it would be great if they were. I've long wanted to add that. Hearing that someone is hitting that deficiency gives me more reason to get it done.
There are two missing pieces for enabling the desired behavior:
1) pi-Stomp specific code doesn't currently listen to external MIDI messages. As they come in via wifi/USB/MIDI jack, they are relayed to the MOD host/UI via the Alsa layer. We'll need to add a listener and event handler.
2) The MIDI mappings for pi-Stomp controls (eg. onboard footswitches, analog pots, expression, etc.) are known by pi-Stomp (obviously), but external controls are not. The event handler needs to know what to do with a msg when received. The MOD API does not include a method for obtaining MIDI learned mappings. We'd need to add that. Fortunately, I just tried a simple hack to prove it is possible, and it looks like it is.
I'll try to make some headway on these in the new few weeks and update this thread as appropriate.
Regarding control of pi-Stomp with two devices, yeah, that'll work via wifi router, but if you switch to hotspot mode, by definition, that'll only be available to one device. If your touchOSC client can interface over bluetooth, you could enable that on the pi, and likely achieve the behavior you're looking for. I have configured /boot/config.txt to disable bluetooth on the pi cuz it's generally not required, so why use CPU and created extra potential for EMI noise? Also, it uses the same UART that is used for connecting wired serial MIDI. But if you're not using that, you could enable bluetooth (bottom of /boot/config.txt) and see if touchosc2midi will handle incoming OSC via bluetooth.
