QTR-1A Reflectance Sensor
... for edge detection and line following applications. The reflectance
measurement is output as an analog voltage.
The Pololu QTR-1A reflectance
sensor carries a single infrared LED and phototransistor pair ... (which is typically 5 V) as a function of the reflected
IR. Lower output voltage is an indication of greater reflection
The LED current-limiting resistor is set to deliver approximately 20 ...