The SparkFun Line Sensor Breakout - QRE1113 (Digital) is a compact and versatile device that features a digital output. It uses a capacitor discharge circuit to measure the amount of reflection. This sensor is ideal for line sensing applications where only digital I/O is available. It is compatible with both 3.3V and 5V systems. The QRE1113 IR reflectance sensor on the board consists of two components - an IR emitting LED and an IR sensitive phototransistor. When power is applied to the VCC and GND pins, the IR LED within the sensor lights up. A 100Ω resistor is included on the board and is placed in series with the LED to limit current. The phototransistor's output is connected to a 10nF capacitor. The quicker this capacitor discharges, the more reflective the surface is.These sensors are commonly used in line-following robots. Since white surfaces reflect more light than black ones, the capacitor will discharge more quickly when directed at a white surface than at a black one. This makes it possible to differentiate between different surface colors and patterns.The power input and output pins are conveniently brought out to a 3-pin, 2.54mm pitch header. For easy attachment, the board includes a single mounting hole. A compact size of 7.62mm x 13.97mm makes it easy to integrate into various projects.SparkFun also offers an analog version of this board for applications that require analog I/O.Key Features: * Operates at 5VDC * Requires a supply current of 25mA * Compatible with digital I/O * No need for an ADC * Optimal sensing distance of 3mm Relevant Documents: * Schematic * Eagle Files * Datasheet (QRE1113) * GitHub https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-01-23 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-03-23 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-04-21 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-11-02 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-11-11 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-11-14 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2025-12-21 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-01-22 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-01-30 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-02-02 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-02-05 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-02-10 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-02-18 https://elecena.pl/product/27745841/sparkfun-line-sensor-breakout-qre1113-digital 2026-04-12