Pololu QTR-8A Reflectance Sensor Array

Pololu QTR-8A Reflectance Sensor ArrayThe QTR-8A reflectance sensor array is a highly efficient module designed for line-following robots and general-purpose proximity or reflectance sensing. It features 8 IR LED/phototransistor pairs mounted on a 0.375″ pitch. The LEDs are arranged in pairs to reduce current consumption, and a built-in MOSFET allows for the LEDs to be switched off, providing power-saving options. Each sensor outputs a separate analog voltage, which can be easily interfaced with microcontrollers for various applications.QTR-8A Key FeaturesAnalog Voltage Output: Each sensor produces an analog voltage between 0 V and VIN, corresponding to the amount of reflected IR, making it easy to measure reflectance.Power Efficiency: LEDs can be turned off using the onboard MOSFET to conserve power, with current-limiting resistors adjustable for 3.3V and 5V operation.Flexible Interfacing: The sensor outputs can be read directly by a microcontroller’s ADC, or through a comparator to generate digital signals.Breakable Design: The module can be split into two smaller, independent sensor arrays if space is limited or fewer sensors are needed.QTR-8A SpecificationsDimensions: 2.95″ x 0.5″ x 0.125″ (without header pins)Operating Voltage: 3.3-5.0 VSupply Current: 100 mAOutput Format: 8 analog voltagesOutput Voltage Range: 0 V to supplied voltageOptimal Sensing Distance: 0.125″ (3 mm)Maximum Sensing Distance: 0.25″ (6 mm)Weight: 0.11 oz (3.09 g)Interfacing Options:Microcontroller ADC: Directly measure the analog voltage outputs.Comparator: Convert analog voltages into digital signals for microcontroller I/O.Digital I/O with Comparator: Use the microcontroller’s internal comparator for simple digital signal interfacing.Applications:Line-following robotsReflectance sensingProximity detection in robotics and automationAdditional Information:Compatible with Pololu AVR library and Arduino library for seamless integration.Ships with a 25-pin 0.1″ header strip and a 100 Ohm through-hole resistor.Included Components:25-pin 0.1″ header strip100 Ohm through-hole resistorThe QTR-8A reflectance sensor array provides a flexible and efficient solution for a variety of sensing needs, making it an excellent choice for robotics enthusiasts and developers.