Perhaps you’ve considered building a line following robot, but don’t know where to start. Or maybe you’d like a more challenging solder kit than a simple badge. If so, then you might consider the D2-5 Smart Tracking Robot Car.
The device is cleverly made with a PCB forming both the body of the car and the chassis, resulting in a design that’s not much more expensive than simpler solder badge kits. The device uses transistors to switch a pair of motors propelling two wheels. To follow the line, on/off feedback is provided by one LED and photoresistor pair for each wheel. As seen at the end of the video below, this does a pretty good job staying on the track.
If you want to know exactly how this works, the circuit diagram is published on the product listing page. Besides the circuit, one other clever trick is that it only uses a screw and cap nut to keep the non-driven side off of the ground. While this wouldn’t be good in rough terrain, this simple setup is a good low-cost wheel alternative for smooth surfaces.
