Herbie the Mousebot
By user12607856 on May 29, 2007
Yesterday, I finished the Herbie the Mousebot kit that I'd bought at the Maker Faire about a week ago. It was fairly straight forward. The instructions are excellent. I only made three mistakes and I was easily able to correct each one. My only advice here is to read the instructions all the way through two or three times and walk through all the steps beforehand, to make sure you completely understand them. My excuse is lack of sleep.
Herbie has two IR sensors in its head. These work well. In a dimly lit room, you can shine a flash night around on the floor, and Herbie will follow the light very closely. There is also circuitry in it's "tail" and "whiskers" to reverse the motors and backup, if it touches something. That seems to nicely get it out of most blocking situations.
Herbie is based upon a robot designed by Randy Sargent for the 1996 Seattle Robothon "Line Follower" contest. It didn't win (it came last), but Randy released the "Herbie" circuit onto the Internet, and it was picked up and built by a lot of people around the world.
There is a version of Herbie (Project #3: The Herbie Photovore) in Junkbots, Bugbots and Bots on Wheels, an excellent book for those who would like to build simple robots, mostly from spare or scrap computer and electronics parts.
Also, if you don't want to buy the kit, consider the Mousey the Junkbot article that appeared in edition #2 of the Make magazine. The link to the sample PDF on that page is broken, but you can easily find it via the Wayback machine.
There is an optional step you can do with Herbie. You can solder an IR LED and resistor into its butt and then, as it's moving around, it'll be shining a light for other mice to follow. Hopefully the Herbie Photovore and/or Mousey the Junkbot will be able to follow that. If that's the case, it's time to try to make one of those.