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joshnishikawa / MIDIcontroller

A library for creating Teensy MIDI controllers with support for hold or latch buttons, potentiometers, encoders, capacitive sensors, Piezo transducers and other velocity sensitive inputs with aftertouch.
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easy way to incorporate this library with a button matrix? #8

Closed stonepreston closed 3 years ago

stonepreston commented 3 years ago

This library looks great! Glossing over the examples and it seems like the button objects are pretty much configured to be directly connected to a pin, is there a way to get things working with a matrix of buttons?

joshnishikawa commented 3 years ago

There's not currently an easy way to setup a matrix of buttons. It seems like there should be but there are a few different ways to wire up a matrix depending on what hardware you're using or whether multiple buttons on the same row/column should work at the same time etc. I've never actually made a button matrix but I'll try it when I get a chance. Hopefully I can come up with something simple enough to include in this library. Any info or insight is appreciated.

stonepreston commented 3 years ago

That would be awesome. I feel like any midi controller thats more than a few knobs and buttons would be using a matrix since it saves so many pins. I have not actually made one yet either haha but Ive done lots of research. For matrix scanning there is this keypad library that seems very easy to use to get a matrix up and running.

For general theory about button matrices the mechanical keyboard community has a wealth of resources. Here is a good overview of the matrix, and here is a nice guide on handwiring and different ways of soldering the diodes and what not.

joshnishikawa commented 3 years ago

It looks like the 'Keypad' library has button matrixes pretty well sorted out. It should be just a matter of writing a sketch that uses the Keypad library to send MIDI messages instead of key presses. It would be interesting to see a proof of concept. However, increasing the number of MIDI inputs is generally done with MUX chips as they are very cheap and simple to implement. I've added a sketch for muxed inputs to the examples.