Line Sensor

The core sensor of every line-following robot. An infrared LED shines downward and a phototransistor reads the reflection: white surfaces bounce light back strongly, black lines absorb it. An onboard comparator converts this to a clean digital HIGH or LOW, with a potentiometer to set the threshold. Mount it 5-15 mm above the surface and adjust the potentiometer under your actual track lighting, not on the bench, since ambient light shifts the trip point. Clean digital output, no analogue processing required; Adjustable sensitivity for different surfaces and heights; Indicator LED shows detection state during setup; Very fast response suits high-speed line following