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This is the first robot I made in toy motors and all from scratch. It is a robot that follows the white line on the black surface. To keep the design simple the robot does not have much of components, it works using two motors and two transistors. Refer the attached file for full details of the robot.
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/robots/show/line-follower-robot