Help creating a diy multiple keyboard midi controller.

[u/svmba-vhs]

Hi,  I'm a newbie in diy midi controller and I wanted to build an organ console with 3 keyboards, a pedalboard and many buttons. For the keyboards I bought 3 m-audio keystation to disassemble them and use there own electronic so it would be easier for me since I'm a newbie so it was just more convenient for me.  For the pedal board I bought one from an old organ that I "midified" using reed switches and a Teensy 4. I first wanted to go the easiest way to me and do 1note=1pin but it's rly not convenient. Also for the whole thing I would end up with 4 different midi device (3 m-audio and the Teensy) running into a USB hub into my computer and I started to think that it would be way easier if all the keyboard and buttons would act like a single midi keyboard but for example too keyboard is chanel 1 then 2 etc...

Is it possible to connect those m-audio keyboard on a Teensy and "reed" them ?  If so, how can I put so many different input into a single teensy ? I heard about matrix but I genuinely didn't understand how it works and I didn't find easy to understand tutorial yet.

I'm sorry that this post isn't rly about synthesizer but I thought that to got help for this kind of diy midi controller thing this subreddit would be perfect.

[u/hyper_espace]

r/SynthDIY