Launching Angry Birds from a slingshot on your iPhone screen is fun, but actually launching Angry Birds from a slingshot sounds difficult, and borderline dangerous (well, definitely dangerous to the bird, variably dangerous to you depending on size of bird and degree of anger). A clever hack over on mbed shows you how to have the best of both worlds–real slingshot, digital birds–by turning a slingshot into a USB peripheral for playing Angry Birds.
The idea here is to turn the slingshot into a USB mouse, and thus translate all the physical movements of the handheld projectile launcher into the corresponding mouse controls necessary to make the slingshot on the screen emulate the slingshot in your hand. This requires the implementation of an accelerometer that can track the tilt of the slingshot and a rubber stretch sensor that can identify how much sling tension, and thus thrust, you are putting into your shot.
Building the thing is a mix of digital (wiring up the three-way accelerometer, the microcontroller, the stretch sensor, the USB connector, etc.) and the analog (whittlin’ yourself a slingshot). After that, it’s mostly just adding the code, which is included in full over at mbed along with the rest of the instructions on how to hack your way to better bird-launching. Enjoy.