There you go, a fantastic DIY project that involved LEGOs, electronics, and robotics.
As any good engineering project goes, we will start out with a problem and a solution. The problem is going to be to build a Lego robot with sensors, a motor controller, and a microcontroller that 1. Follows a black tape. 2. Upon reaching the end of the tape will pause for three seconds. 3. After pausing for 3 seconds will return back to the starting point.
This reminds me of my first robot. I had just about the same setup as he does except I had touch and IR sensors connected to a Basic Stamp all on a LEGO body. I used a hand built H-Bridge to drive the motors and not a 2998. It worked OK except the motors were geared wrong and it went far too fast. After smacking into one too many walls I took it apart and started on another project.