Recommended · for beginners
MAKE THIS BUTTON BOX | 32 FUNCTION w ENCODERS
Why people recommend it
Used as a build guide for an Arduino button box for flight simulators, and pointed to for how its switch matrix is wired.
Watch for: Check the wiring closely if using three-way toggle switches
In their words
EDIT: I got the idea from this video, which explains some of it, but no code.
RussianImport on arduino.stackexchange.com, Aug 2018. CC BY-SA.