[Shawn] wrote in to share his post outlining the addition of rapid fire to an Xbox 360 controller. He’s going all out with this mod by including a pretty beefy microcontroller. But you get a lot of functionality for that. You can just make out the trimpot below and to the right of the green A button. This tweaks the speed at which your right trigger repeats. Next to the trimmer is an amber LED which indicates whether the hack is enabled or not. The switch to the left of the D-pad simply patches the add-on circuit into the right trigger hardware.
Some might raise an eyebrow when we call the ATtiny85 used here beefy. But considering the job at hand, we’re sure a lot of the lower end of the ATtiny family will work just as well. [Shawn] soldered everything up on a piece of protoboard and removed one of the rumble motors to make room inside the controller. The video after the break is pretty shaky and out of focus, but you can clearly hear him explain how the hack works.
If you’re looking for a rapid fire mod that doesn’t require programming a chip, perhaps you could just repurpose the PWM from the LED.