Look, [lord feistel] is doing glitching attacks on an ATMega328P! All you need is an Arduino board with its few SMD capacitors removed or a bare 328P chip, a FET, and some sort of MCU to drive it.

The watch rocks a simplistic, bare bones design with the PCB ... ATmega328P, as seen in the popular Arduino Uno, and it’s paired with a DS3231M real-time clock module to keep accurate time. 13 ...