QRE1113 Infrared Reflection Sensor Module Purple - Digital Output, 3-Pin Header

The module is designed to operate from 3.3V to 5V DC, making it directly compatible with most microcontroller platforms like Arduino (5V), Raspberry Pi (3.3V), ESP32 (3.3V), and STM32. The onboard current-limiting resistor ensures safe operation across this entire range without requiring external components.

The module uses a capacitor discharge timing circuit. The output pin provides a digital pulse whose duration (discharge time) is inversely proportional to the reflected IR light intensity. To read it, connect the output to a digital I/O pin configured as an input and measure the pulse width using your microcontroller's pulseIn() or timer/capture functions. A shorter pulse indicates a more reflective (lighter) surface.

The standard pinout (viewed from the component side) is: Pin 1 (VCC) for 3.3V/5V power input, Pin 2 (GND) for ground, and Pin 3 (OUT) for the digital timing output. The included header strip allows for direct connection to a breadboard or Jumper wires. Always confirm the pin markings on the PCB silkscreen before connecting power.

Yes, it is effective for short-range object detection and proximity sensing based on surface reflectivity. It works best at close ranges (typically a few millimeters) and is ideal for detecting the presence of objects, tape lines, or encoder marks. For longer-range detection, consider a dedicated IR proximity or Time-of-Flight (ToF) sensor.

No external components are required for basic operation; the necessary 100Ω resistor and 10nF capacitor are onboard. Calibration involves software tuning: you measure the output pulse widths for known 'dark' and 'light' reference surfaces in your application and set a threshold in your code to differentiate between them, optimizing for your specific target distance and ambient light conditions.