Midi controlled a/b pedal?

I'm messing around with Arduino/microprocessor programming to throw together a box that basically does what a RJM Gizmo does (amp/channel switching). It'll have MIDI in, which goes to the MCU, which then controls a set of four relays. The relays will open and close, creating the same result as stepping on a footswitch.

To handle A/B switching, I came across this and stuffed it and a bunch of 1/4" connectors inside a Hammond 1590B enclosure. In my testing so far, I have a SPDT footswitch going into the A/B box, and it works like a charm. I suppose I could've fit all the MIDI/switching/A/B into the same [larger] box, but I wanted to make sure I could get the easier stuff down first. I have some parts on order for the MIDI switching, and I'll hopefully get everything up and running some time next week.

IMG_20120919_210315.jpg
 
I should add that I'm using the A/B in reverse. I am the keyboard and rhythm guitar player in the band, and whenever I play something on keyboard, I'll have it switch to the other input, which is being fed a DI track. Would be kind of hard to play a keyboard solo and play rhythm guitar simultaneously, otherwise. ;)

I haven't tested it the way you have in mind, but I don't see why it wouldn't work like that.
 
I'm messing around with Arduino/microprocessor programming to throw together a box that basically does what a RJM Gizmo does (amp/channel switching). It'll have MIDI in, which goes to the MCU, which then controls a set of four relays. The relays will open and close, creating the same result as stepping on a footswitch.

To handle A/B switching, I came across this and stuffed it and a bunch of 1/4" connectors inside a Hammond 1590B enclosure. In my testing so far, I have a SPDT footswitch going into the A/B box, and it works like a charm. I suppose I could've fit all the MIDI/switching/A/B into the same [larger] box, but I wanted to make sure I could get the easier stuff down first. I have some parts on order for the MIDI switching, and I'll hopefully get everything up and running some time next week.

IMG_20120919_210315.jpg

So did you have to do any programming yourself? Looks pretty cool!

Maybe this glab looper can be for you?
http://www.glab.com.pl/midi_2xloop_en

in manual page 11 you can see example of aby
http://www.glab.com.pl/img/um_m2l_14062011.pdf

89 euro on thomann

Bingo! That is it.