A reflector sensor provides the AEV information on how far to travel for the function calls: GoToAbsolutePosition and GoToRelativePosition. These function calls will be programmable to the Arduino board so that the reflectors will be able to read how many revolutions it will take for the track. A revolution will be 8 “marks.” In order to know how many marks for the AEV to travel, use the conversion of .4875 inch = 1 mark.
Here the two red sensors are the readers and will be reading the silver tab (reflectors) on the wheel shown above the white screw.