Tweet Roller is a small project I cooked up with a classmate for an Arduino based class I took in my undergraduate. Thanks to Twitter’s API changes actually a lot of it ended up being written in Processing, but with the Arduino acting on the physical world. When the system detected a tweet with the target hashtag it would start a ball running along a marble run, and at the end tweet the time taken to complete the run and a picture of the ball on its journey.
This especially tested my marble run building skills! For full details of the project see tweetroller.ipodling.co.uk.