SparkFun Line Sensor Breakout - QRE1113 (Analog)

The SparkFun Line Sensor Breakout - QRE1113 (Analog) is a compact and versatile board that features an easy-to-use analog output. This output varies depending on the amount of infrared (IR) light reflected back to the sensor, making it perfect for line sensing applications. It's compatible with both 3.3V and 5V systems, offering flexibility in various project designs.

The QRE1113 IR reflectance sensor on the board consists of two parts: an IR emitting LED and an IR sensitive phototransistor. When power is applied to the VCC and GND pins, the IR LED in the sensor illuminates.

A 100Ω resistor is included on the board and is placed in series with the LED to limit current. Additionally, a 10kΩ resistor pulls the output pin high, but the output starts to decrease when the LED light is reflected back onto the phototransistor. The more IR light sensed by the phototransistor, the lower the output voltage of the board.

This sensor technology is commonly used in line following robots. White surfaces reflect more light than black ones, so when the sensor is directed towards a white surface, the voltage output will be lower than when it's directed at a black surface.

The power input and analog output pins are conveniently brought out to a 3-pin, 2.54mm pitch header. The board also comes with a single mounting hole, making it easy to secure onto any surface.

A digital version of this board is also available for those who prefer digital output over analog.

Key Features:

• Operating voltage: 5VDC
• Supply current: 25mA
• Optimal sensing distance: 3mm
• Dimensions: 7.62 x 13.97 mm

Supporting Documents:

• Schematic
• Eagle Files
• Datasheet (QRE1113GR)
• Bildr Tutorial
• GitHub