EV3 - Light Follower

This is a post for EV3 Track3r light follower. Track3r has an attached color sensor which helps it to follow the light. In the video, the kids are projecting a focused light beam with a torch, over the color sensor attached to the robot. The rest of the room is dark. When the robot follows the light, the resulting effect is like, the kids are pulling the robot with the light (without any physical connection to the robot). In my opinion, it is an interesting effect! 

NOTE: It would be good if you read the article for EV3 - Line Follower, before continuing to read the below article. 

For the light follower to function, calibration of "Bright Light" and "Dark" intensities has to be done. The actual algorithm to follow the light is influenced by Jacek Fedorynski's Line Follower NXC program. The LeJOS (Java) program has one class "LightFollower". This class initializes the color sensor and calibrates the sensor for "Bright Light" and "Dark" values. Further, this class has the algorithm to follow the light - given the calibrated values and the light intensity at any given point in time. The rmotors are powered based on the difference between the calibrated values and the light intensity at a given point of time. Below is a small video clip for Light Follower function.