Various designs. One of my first designs was a dual stepper motor driver, before the widespread availability of all-in-one driver chips, using an AVR2313 controlling L298 H-bridges. Others have included LED lighting, Chain motor controller, UAV hardware, motor drives, CNC controller, a stackable DIN-rail controller for mixed CNC / machine vision systems (with modules for Raspberry Pi, Jetson Nano, and ESP32 controllers talking to axis controllers, inputs, outputs, load cells etc) and various other projects.
