I'm new to the whole micro controller thing, and pretty untrained in electronics in general, but I am a keen musician and I have given myself the task of converting an organ into a midi keyboard controller.
The organ has 2x 44 key manuals and I'd love both keyboards to be separate but functional with transpose buttons for both. I also want to use sliders to create drawbar control as well as various other knobs and switches for other uses.
The question is what would be the best arduino board/s to get for a project like this. I'd love it to be an all round midi controller for both PC/mac and ipad, but would still settle for just laptop operation.
Looking forward to a new chapter of building things!
Before you dive-into a project like this, I'd suggest you start by making a simple little "experimental" MIDI keyboard with a few push-buttons for keys. You can start with just a few buttons/notes, or maybe 12 buttons for one octave. For development of the MIDI side of things, you can generate MIDI messages in software so you don't actually need buttons or a keyboard.
You might be able to "tap into" the key-switches and basically build a MIDI keyboard from there, but I don't think it would be worth the effort, and if the organ is worth preserving you probably don't want to make those kinds of modifications. You can buy a simple MIDI keyboard for a couple-hundred dollars, and it's probably better than what you'd end-up with by "hacking up" your organ.
Or if you don't care about preserving the organ, I suppose you could build a MIDI keyboard from the parts. But it's going to take you several months and who knows how it's going to turn out... It depends on what you're after... If you want to have fun with electronics it might be worthwhile. But as a musician, it's probably not worth the effort (or the cost).
There are a few computer applications that can convert audio signal to MIDI, but as far as I know they don't work very well with chords or multiple instruments. Try searching for "WAV to MIDI", or "Audio to MIDI". If you can find an application that works reliably polyphonically, in real-time, you can run it on your computer and you won't need an Arduino. (Converting one note at a time from audio to MIDI could be done with the Arduino.)
I don't think that's practical...