Andy Felong needs a bit of assistance when parking in his garage because there’s a ladder sticking out just in the wrong place. A typical bodge-it solution would be to hang a tennis ball from the ceiling so that it touches the car’s glass before a collision occurs. However, Andy decided he wanted a digital solution. So, he took a Raspberry Pi and hooked it up to a USB distance sensor. He then had the Pi audibly inform him the distance between the sensor and the car. He’s done some nifty programming to detect whether the car is moving, or whether it’s stationary. He’s written it all up on his blog which you can read here.