Following lines, detecting colors, responding to light. It is still far from "seeing", but the LEGO Mindstorms EV3 & NXT sensors could be very useful when used properly.
In this video we are showing how to use two light sensors to do basic aligning on a black line. This is always needed at the competitions. We also show an example for following a line with two sensors.
In this video tutorial I give a step-by-step explanation of how to implement a block for aligning to a line. The block was first used in lesson 28. Aligning to lines is probably the most powerfull way to know the position of the robot on the FLL Competition field and to be able to execute the missions precisely at 100% of the time.