Photoelectric Sensor Configuration

[frcchile]

Hey guys,
Our team was having some difficulties with the configuration of the photolelectric sensors for the autonomous mode. We were trying to set up a basic line follower but we are unable to configure them to follow gray lines.
The sensors output the same thing for any and every surface and line , they only project the green when we raise the sensors high up. Currently, they are approximately 2 inches above the ground.
We set the sensors to output a binary value to see when it was on or off the line, but when the robot is on the ground, all the sensors are outputting 1, even if we change the surface and move the robot around.

Thanks,
Team #2576 Corazon de Chileno