Line Following with only One Ground Sensor with a Raspberry Pi Pico 2040 and Zepto Forth.
In the book ELEMENTS OF ROBOTICS by Mordechai Ben-Ari and Francesco Mondada, a section (p. 48) is dedicated to "Line Following with a Single Ground Sensor." It is an approach to this application that will be implemented with ZeRobot. It is important to note that the Raspberry PiCO 2040 has three analog ADCs; it is therefore possible to detect several shades of gray. This setup is described here: There is an infrared diode and a phototransistor. The circuit is a grayscale track in the transverse direction. Measuring the value at the center of the track provides a reference to guide the robot. For example, a value lower than the reference will move the robot to the right, and a value higher than the reference will move the robot to the left.