using a fluxamasynth with midi controller shield

Do I have to program them one at a time or do I stack them three shields high and add more code?

Oh I use the uno to program my boards. :stuck_out_tongue:

Stack them up just make sure that they all use different pins so you don't get conflicts.

..and DO NOT CROSS-POST.
Identical post deleted.

sorry, do you mean jumper settings on the three boards? or code? computer settings? :stuck_out_tongue:

Stack them up just make sure that they all use different pins so you don't get conflicts.

Do I have have to use two sketches in one upload? Or mix the two codes as one sketch.

I mean physical inputs and output pins. In general you cannot have pins working for more than one board. The exception would be where you are using a bus like SPI, I2C or similar.

You cannot have 2 sketches running at once so you need to combine the code into one sketch to do what you want.