DIY Arduino parking sensor

I recently created a workbench in the far end of my garage. This however resulted in about 10 cm of clearance in total in front and behind the car. So needless to say it would be great if I had my own personal parking assistant. So I set out with the goal of creating a simple parking assistant, which had to be cheap, small and accurate.I then browsed http://www.dx.com for the parts i needed and landed on the following pieces: Arduino nano v3 HC-SR04 (Ultrasonic distance sensor) Starter kit (breadbord, resistors, cables, LED’s, etc.) I read a couple of tutorials and started piecing the parts together. »