8-Array QTR-8RC Line Follower Sensor Module – Digital IR Reflectance Sensor (Clone)

The 8-Array QTR-8RC Line Follower Sensor Module is a multi-channel infrared reflectance sensor designed for robots that need to detect lines, edges, and changes in surface reflectivity. It contains eight IR sensing channels arranged in a row, allowing a robot controller to determine the position of a line across the sensor array.

Unlike analog reflectance sensors that provide a voltage proportional to reflected light, the QTR-8RC-style design uses an RC decay timing method. The microcontroller first charges the sensor capacitor and then switches the I/O pin to an input to measure the discharge time. Reflective surfaces generally produce shorter discharge times, while darker surfaces produce longer readings.

This digital timing approach can be useful for fast line-following algorithms and avoids the need for eight dedicated analog input channels. The sensor is therefore suitable for Arduino-based line followers, autonomous vehicles, maze-solving robots, AGVs, and robotics learning projects.

Key Features

• 8 independent infrared reflectance sensing channels.
• QTR-8RC-style digital RC timing output.
• Compatible with the Pololu QTR-8RC library approach.
• Suitable for fast line detection and tracking.
• Does not require a separate ADC channel for each sensor.
• LED control input for managing IR emitter operation.
• Approximately 100mA maximum supply current.
• Recommended sensing distance of 3–5mm.
• Suitable for Arduino and other compatible microcontrollers.

Applications

• High-speed line-following robots.
• Racing line follower competitions.
• Maze-solving robots.
• Autonomous mobile robots.
• Automated Guided Vehicles (AGVs).
• Edge and surface contrast detection.
• Educational robotics and STEM projects.
• PID-based robot navigation experiments.

Usage Notes

For reliable line detection, mount the sensor parallel to the floor and maintain an appropriate distance from the track. A sensing height around 3–5mm is recommended according to the supplied specifications.

Calibration should be performed before normal operation because sensor readings depend on the track material, surface color, ambient lighting, mounting height, and individual sensor characteristics.

Keep the IR sensor faces clean and avoid exposing the electronics to excessive moisture or physical impact.

Product images are for illustrative purposes only and may differ from the actual product. Product specifications may vary slightly between manufacturing batches.