Adding CdS photocell sensors to your Tiny Wanderer robot allows it to see a spectrum of light that is similar to what humans perceive. With two sensors, the robot can monitor two directions for light level differences and be programmed to either turn to or to avoid high light levels.

In this guide I will show how to add the CdS photocells to the Tiny Wanderer and provide a program for “moth” or “anti-moth” behavior. From this point it is a short step to experiment with making the classic Braitenberg vehicles.