This project is a series of custom PCBs, with a combination of functions that allows it to be re-used for a variety of escape room puzzles, depending on which parts it is populated with. It started as an arduino shield with MOSFET outputs, an H-bridge for driving linear actuators or dc motors, power shift registers providing 32 LED driver/buzzer/other 12V load outputs, and level shifters for easy communication with a raspberry pi.
As puzzles have become more networked the GP3 has evolved into a Raspberry Pi hat containing those functions and more.