In this thread:
'kittycatonline" (gotta love that user id) posted a video of stepping the tempo up and down using a foot switch. Although not confirmed, I believe that it requires a modification to the Beat Buddy.
I posted a video of my solution in the same thread but I am creating a new thread just in case it gets lost over there.
So, here’s my video:
The code and wiring diagram are attached.
I am just using an Arduino UNO to detect which of the two switches are pressed and then send out the appropriate CC commands to the beat buddy to step the tempo up or down. By sending the CC commands 5 times for each key press I can step the tempo up and down in steps of 5.
A couple of other things you could do with something like this are:
Press and hold the switch to step up or down continuously and then just do single steps up or down for individual key presses.
MIDI merge so you could have something else sending midi to the BB and still control the tempo manually using the foot switch. The midi from the other device would go to a midi in to the Arduino that would then merge that midi with anything it generates as a result of the key presses.