Two of Our Favorite Line Sensors Breakout Boards (QRE1113) from Sparkfun and Pololu :D

Sparkfun’s Schematics

See datasheet of QRE1113: http://cdn.sparkfun.com/datasheets/Sensors/Proximity/QRE1113.pdf

See the tutorial from Bildr on how to use: http://bildr.org/2011/06/qre1113-arduino/

Buy from Pololu at 4.25 USD per pack. https://www.pololu.com/product/2459

Buy from Sparkfun at 2.95 USD each: https://www.pololu.com/product/2459

HOW ABOUT SOME LINE SENSOR ARRAYS? FROM POLOLU :)