Today we have started to put our robot together and developed a masterpiece line follower.
1 light sensor
3 wheels(2 big, 1 small)
We used all of these parts to create our line follower and the principle was that the light sensor detects the line and then works both the motors which rotate the wheels. The small wheel is used to help the line follower to rotate 360 degrees. When the light sensor doesn't detect the line one of the motors stop and the robot spins around until it finds the line again.