keychain GameCube – A miniature GameCube-style keychain controller isn’t just a fidget toy anymore. [Brux] opened a Backpack Buddies unit, replaced its inside with SMD switches and wiring, added a joystick mechanism, and used an RP2040 to translate inputs to a real GameCube contr
The little controller looked like the kind of thing you’d flip in your hand and forget about. Then [Brux] cracked it open.
The starting point was a keychain/fidget toy made by Backpack Buddies. The outside already had the parts that feel right: buttons you can press and joysticks that move. But there was an intrusive thought sitting behind the novelty—what if it actually worked like a game controller?
Inside, the project wasn’t a simple swap. Once opened at the seam, [Brux] had to redecorate the interior to clear space and mount switches. Instead of using a traditional PCB, the build glued SMD switches to custom 3D components. Thin enameled wire then connected those switches, before the original buttons were reattached after more plastic surgery.
With the switch and button section in place, the joystick innards went in next. Finally, [Brux] glued on the last pieces: the final buttons and joystick caps.
The part that makes it more than a moving imitation came with the brain of the system. To connect to a real GameCube, an RP2040 was used to handle the translation of control inputs to the GameCube controller protocol.
To finish the job, [Brux] sacrificed an actual GameCube controller for its cable and controller connector. As shown in the video, the keychain build does work—and turns into a controller that’s effectively ready for guests to use.
GameCube controller keychain controller RP2040 SMD switches DIY electronics fidget toy joystick rebuild enameled wire custom 3D components
So it’s basically a GameCube controller… but for your keys? Wild.
I don’t even get why people need a keychain controller like just play on the console lol. But also the fact it “works” is kinda impressive? Like how is it not gonna break in a week.
Wait so it turns into a real GameCube controller protocol… but isn’t GameCube like super old and they don’t use Bluetooth or whatever? I’m guessing they just stole the cable from some other controller and wired it back wrong, but hey if it connects then whatever.
Backpack Buddies really out here making toys that get hacked into controllers, smh. I saw the “RP2040” and thought that meant it runs Doom or something, like a mini console brain. Also the SMD switches and enameled wire part sounds like a lot for a keychain… but I mean if guests can use it I guess that’s the point? Idk I’m tired just reading about it.