multiplex

Yes, this MIDI controller has a 4×4 grid that you have undoubtedly seen way too many times. No, it doesn’t have RGB Will it actually get used? Probably not. But hey, its a great opportunity to learn some electronics! And implementing key matrices is not as trivial as you might think. Schematic First off, if you haven’t already, check out this excellent post by Dave Dribin to learn about ghosting and masking....

I really like rotary encoders as user input devices, they’re free of analog noise shenanigans, have no fixed positions, can be augmented with velocity control… Just a really nice way for the user to navigate around in menus or adjust parameters. That said, they do take up at least one extra pin per encoder compared to potentiometers, and of course, they require either polling or pin change interrupts to react to changes in the states of their pins....