While a line-following robot may not be the newest project idea in the book, this one from [Edison Science] is a clean build using modern components and gets a good speed thanks to PID control ...

Inside the BeatBot an Arduino reads 9 infrared sensors for line detection at 100 samples a second. A digital servo controls the Ackerman steering mechanism to follow the line on the track or floor.

An Arduino-based robot for people who don’t know how to build robots "Sparki" ideal for teaching kids (or adults) how to program robots.