While the Nintendo GameCube stood deep in the shadows of the PS2 in its day, its controller remains a popular target for all sorts of modifications today — many of them involving LEDs, thanks to a translucent bottom and button option. As an avid player of the Super Smash Bros. series, [goomysmash] is of course an owner of the very same controller, which motivated him to write GoomWave, a “versatile and hackable LED library”. In an impressively detailed Instructable, he shows how to modify your own controller in two different ways to make use of the library for yourself.

Initially inspired by the Shinewave mod that lights up RGB LEDs in colors associated to pre-defined moves in Smash Bros, [goomysmash] aimed to improve on it and add more versatility from the very beginning. Its latest iteration comes in a simplified ABXY-buttons-only variety using an ATtiny85, and a full-blown all-button variety using an Arduino Nano. Both of them are powered straight from the controller board, and have different modes where they either react to controller interactions, or are just custom lights. A brief showcasing of all the different modes can be seen in the video after the break, and there a few more details also in an older version’s video, also embedded below.

Mesmerizing LED-blinking aside, we just have to admire the diligence and cleanliness [goomysmash] put into the wiring and fitting everything inside the controller. But in case light mods aren’t your thing or you’re looking for other GameCube controller modifications, how about adding Bluetooth?