Hello, GeekHack!
This is my first post, so please bear with me. I'm currently in the midsts of developing a drop-in replacement controller for the Focus FK-5001, in the form of a board that sockets in place of the Intel chip already present on the focus, and takes over control of the matrix and display with QMK. Because of IO concerns, I'd like to use decade/johnson counters to drive the columns of the matrix and read the rows to save pins. Will QMK provide a way to use counters instead of direct interface with the matrix? I'm honestly still on the fence about what to use in the way of a controller. For all past projects, I've used the trusty 32u4, but I'm considering using a teensy 2.5 for it's great IO and vastly more powerful MCU, I do plan on driving an LCD/OLED in place of the calculator after all. Thank you guys in advance for any advice. Please forgive me if this is a bit of a weird ask.