With an STM32 “Blue Pill” microcontroller doing its best impression of a USB Human Interface Device, the panel bangs out the prescribed virtual key presses when the appropriate encoder is spun ...

As for the electronics, [r0ckR2] went with an STM32 “Blue Pill” board, simply because it’s what he had on hand. The screen is a ST7735 1.44 inch SPI TFT, and the keys themselves are Cherry ...