A Robot that Follows a Line

Line-following robots are popular among robotics hobbyists because these types of robots can be relatively simple to build, and yet are very entertaining as they follow whatever size path you lay out for them. Unlike room-exploration robots that often get stuck against chairs and carpet edges, you don’t have to chase after a well-designed line-following robot.

Most line-following robots have two motors, two front sensors, and a basic electronic circuit for autonomous control. But, a great thing about this type of robot is that it easy to make small changes for added complexity. An simple improvement is to install the robot in a decorative container, along with colorful LEDs. More advanced designs add sensors and a programmable microcontroler for faster speed, smoother turning, or maze-solving.

Sandwich, the line-following robot Sandwich, the Line-Following Robot
This is a simple, yet sleek, line-following robot that you can reproduce in your home laboratory. A racetrack movie appears at the end of the page.
Printed circuit board for Sandwich Printed Circuit Board for Sandwich
Stuffing instructions for a professional, double-sided, printed circuit board for Sandwich. The board has silkscreened part numbers and a solder mask, making it a fast, easy, and reliable way to build.
Jet, the fast line-following robot Jet, the Ultra-Fast Line-Following Robot
Learn the technical extravagance that competition leads to, as a line-following robot breaks the 100 cm/s barrier. Includes plenty of techno-babble and names of people you don’t know.
A fun line-following robot. Sweeeeet! Sweet! The Line-Following Robot
An m&m’s candy container provides a fun body for a smart line-following robot. Videos show the auto-contrast, dark-or-light detection capabilities. Sharp turns and crossovers don’t slow this car down, but it can automatically stop at the end of the line.
Thumbnail Yummy Candy Tin Robot
Yummy is a line-following robot made from an m&m's candy tin, in homage of Sweet. Yummy features a light sensor for detecting when the candy tin has been closed, to delay starting the motors as long as necessary. The rear tail lights use 10 mm red LEDs with Fresnel lenses.
A robot solves a maze of lines Line-Maze Solving Robot
A multi-deck robot with seven PCBs, nine floor sensors, one LCD, four buttons, and two quadrature encoders. The robot solves mazes made of white lines on black tiles. The article includes two movies.
Chicago thumbnail Chicago Solar-Powered Line-Following Robot
This robot combines two circuits from other robots to charge/discharge 2 farads of capacitance into a pair of miniature motors controlled by a low-voltage comparator. Four photosensors track the line, which can be either dark or light based on a switch setting.
Wavy thumbnail Wavy - Line Follower
The predecessor to the popular Sandwich robot, Wavy has some extra components and some missing components in comparison. This is one of my favorite robots, particularly for its exaggerated line-following motion.
A tiny robot that fits inside a Monkey Mints candy container. Monkey-Mints Micro Line-Following Robot
A robot that fits in the palm of your hand, built into an Accoutrements candy container. Features ultra-small gearmotors with surface-mount motor driver transistors. Includes a video with interesting patterns that appear as the robot sweeps aside candies.