- Consists of an infrared light emitting diode (wavelength 940 nm) and a high-sensitivity phototransistor (wavelength 800 nm)
- Detects proximity and color of objects
- Minimum detectable width for monochrome lines: 10mm
- Connector: 4-pin Buckled Grove interface
- Digital output: 0 or VCC
- Effective working distance: 4-15mm
The Grove Infrared Reflective Sensor v1.2 detects proximity and color of objects. The reflective photosensor RPR-220 used in this module consists of an infrared light emitting diode and a high-sensitivity phototransistor. Light-colored objects directly in front of the sensor will reflect more infrared light as well as generate more current in the phototransistor than an object with dark-colored surfaces.

When the reflected light is detected, it produces Digital HIGH (or Binary 1) output on the SIG pin. The on-board LED indicator will also glow. If no reflection is detected or if the object is too far from the sensor, the output on the SIG pin stays at Digital LOW (Binary 0). The on-board LED indicator will be off as well.
There is a potentiometer which can be used to adjust the gain of the amplifier (sensitivity of detection).