MIDI and multiplexing for simultaneous notes

Hi everyone,

Perhaps this is something obvious for anyone who is familiar with actually using multiplexers, but I cannot seem to find an answer anywhere. I found some great info about using multiplexers in MIDI controllers for pots and buttons, but my dream project involves midifying keyboards. Has anyone tried using multiplexers in a situation like this? Could I feasibly play multiple notes simultaneously via a mux?

A bit more background about my project if it helps, or if you are interested. I am hoping to convert an old pipe organ console to a MIDI console. I’ll be using a Mega one way or another, but if muxes would work in this scenario, then I could get away with using one Arduino instead of 5 (there will be 4x61 note manuals, a 32 note pedalboard plus numerous other analog and digital controls).

Any advice would be greatly appreciated. It would be great to know the answer to this specific question before I start shopping for hardware!

Thanks a tonne!

Could I feasibly play multiple notes simultaneously via a mux?


MIDI can only trigger one note at a time, but you can turn the notes on one after another so quickly that it sounds like they are starting at the same time. However this has nothing to do with multiplexing.

You can use multiplexing to look at several keys very quickly in succession, which I think is your real question. You do not need to use multiple Arduinos.

What you actually need is several port expander chips to give you more inputs, like the MCP23S17.