Spinning the rotary encoder cycles through a menu of programs on the 16×2 LCD, and the key map just updates automatically for the chosen program.

It is amazing how many Arduino programmes for decoding rotary encoders start with something like: "I looked at all the available rotary encoder sketches ...

With an onboard Arduino Pro Micro, OLED display, and rotary encoder, this controller just needs some custom software to make your CNC dreams come true.