I made myself an MIDI Patchbay, and had to test it with a MIDI footpedal.
Well... before i had the footpedal, i had to open my guitar preamplifer, a Carvin, to figure out how the MIDI was really connected.
Still... i managed to find the schematic of the unit, and then i found how could i get info from the MIDI THRU of my Carvin...
nevertheless, MIDI is a straightforward current loop, one need just to give a decent current to the LED, and thats it. Custom baudrate by the way.