This is how I wired them up for the FriarBot:
-The brown lead has to pull +12v through a breaker. (dont use the +5 output from the digital i/o ports, its not enough)
-The blue lead has to go to the ground pin on a digital i/o port.
-Either the black or white lead has to go to the signal pin on that io port. Only use either the black or white. The white lead is for "sourcing output" - the white lead will go high when the sensor "sees" the line. The black lead is for "sinking output" it will go low when the sensor "sees" the line.
-I used sinking output for our design, but i dont think that it really matters. Just remember that the sourcing output will register a logic 1 in the code, and the sinking registers a logic 0.
See this page for schematics
http://www2.usfirst.org/2003comp/Spe...nersensors.pdf
Also, check out our team site at
www.friarbot.com