I found an old NES (Nintendo Entertainment System) controller, that for some odd reason had been mutilated and got its connector cut off. Would be sad to just throw it out, and I didn’t own a NES, so I decided to make it into a gamepad that would function on my computer. I took it apart, and fitted an Arduino Pro Micro inside of it. The Pro Micro is able to act as a Human Interface Device, so the computer would see it as a keyboard, a mouse or in this case a game controller.
Finding the pinout of the shift register inside the controller was rather easy, and someone else had already gotten the Pro Micro to act as a Game controller.
It ended up working quite well, and I found a suitable black USB cable, to make it look like that it had always been like this.