This project is designed as a way of learning physical computing (the combination of computer programming with electronic circuits) in a fun way.When first starting out with electronics then getting a LED to flash can be quite exciting, and getting it to respond to programming done on a computer is another big leap, but once you have mastered those skills then it can be easy to lose interest. What we need is something that is exciting, fun to make, something you can show off to friends. The next challenge is that it needs to be affordable. It needs to be within a reasonable price that children (or their parents) can pay for an educational toy; unfortunately for most of us this rules out Lego Mindstorms and many commercial robots.