[inches] wanted the power of a Raspberry Pi 3 in a form factor closer to the Pi Zero for a Game Boy mod. This led him to design a custom PCB to interface with one of the less popular items in the ...

For the next revision, [Andrew] added buttons and decided to make it into a Raspberry Pi HAT. This HAT is essentially ... So [Andrew] put the LED driver on the 3.3 V I²C bus.