Parallax QTI Light Sensor

The Parallax QTI Light Sensor uses a QRD1114 infrared (IR) reflective sensor determine the reflectivity of the surface below it. For instance when the QTI sensor is over a dark surface, the reflectivity is very low and when the QTI is over a light surface, the reflectivity is very high. The QTI Sensors were originally meant to sense the outer rim of a SumoBot® ring; however these little line sensors can be very handy for other applications, including line following and maze navigation.