Basic Line Following Robot Tutorial

Well, I have finally had a chance to get over all of my finals, and hopefully did well. I will find out on Monday.
Well, as I have promised, here is my next DIY how to project. Beware, it is going to have to be in depth, and
long. 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.

The next step in an engineering problem is to come up with a solution. Ideas of implementation must be thought of. There are two possibilities of making a robot come back to the starting point after pausing for three seconds. The first and most obvious way is to make the robot turn around and then drive back to the starting point following the line. This way of implementing has a lot of benefits. The first is that it is the easiest to implement, and it is relatively straight forward. When the robot hits the end of the tape, the sensor will notice that it is not sensing the tape anymore, and this will cause the robot to turn around and when it sees the tape again, will continue on its path. There is one problem with this way though. It is common.

We have all seen a line following robot, and it is neat, but not impressive. I wanted to do something that has not been done. I chose to implement my robot the second possible way, and the hardest way to implement. I wanted my robot to sense the end of the line, and then pause, and after a three second pause, I wanted it to drive in reverse and follow the line going backwards using a second set of sensors, so this is the robot that I will present. The only warning, and sad part of this project is that I canÃ¯¿½t find my code. It is on a disk somewhere, and I have no idea where that is. I will provide code for a simple line- following robot though, and will explain the differences. In essence, I will tell you how to build both robots. On a positive note though, I do have a schematic of my robot, so you can see exactly how it is done.