“Suppose you wanted to follow an object in a single plane with a pointer or some other device… and do it automatically. Not only is it possible, it’s fairly easy if you break it down into separate tasks: Attach an infrared light source to the object to be tracked; Connect a stepper motor to outputs on a PICAXE microcontroller; Connect three phototransistors to inputs on the PICAXE microcontroller; Attach the phototransistor array and the pointer to the stepper motor shaft; Write code for the PICAXE µC to make the stepper motor turn as directed by the phototransistors; Okay, maybe it takes a little more—such as electronic design, mechanical design, component selection, and programming skills—but this article will provide you with that work already completed. Read on!”