TCRT5000 IR Line Tracking Sensor Module

The TCRT5000 line tracking sensor has an infrared LED and a phototransistor side by side. The LED shines IR light at the surface below, and the phototransistor measures how much bounces back:

• White or light surfaces reflect a lot of IR, so the sensor detects reflection.
• Black lines or dark surfaces absorb IR, so very little light returns.

An onboard LM393 comparator turns this into a clean digital signal your Arduino can read straight away. Use a potentiometer to fine-tune the sensitivity for different surfaces, lighting and mounting heights.

Put two, three or five of these modules side by side under a robot chassis and you have a complete line follower robot sensor array. It’s one of the most popular sensors for robotics competitions, STEM classes and engineering projects.

Key Features

• TCRT5000 IR reflective sensor. Reliable black/white line detection.
• LM393 comparator. A clean, stable digital output with no flicker.
• Adjustable sensitivity. Tune it with the onboard potentiometer.
• Indicator LED. It shows when reflection is detected, which makes setup easy.
• 3.5V–5V operation. Works with Arduino, ESP32 and other microcontrollers.
• Detection range of about 1–25mm, with the best performance at about 2.5mm.
• Compact 32 × 14mm PCB with a mounting hole for easy fixing.
• Multi-purpose. Line tracking, edge detection, obstacle sensing and counting.

Technical Specifications

Pinout

Wiring with Arduino Uno

Example Arduino Code

const int sensorPin = 2;

void setup() {
  Serial.begin(9600);
  pinMode(sensorPin, INPUT);
}

void loop() {
  int value = digitalRead(sensorPin);

  if (value == HIGH) {
    Serial.println("Black line detected");
  } else {
    Serial.println("White surface");
  }
  delay(100);
}

Test the module over a black line and a white surface first. If the readings are the wrong way round, swap HIGH and LOW in the code.

Setup Tips

• Mount the sensor 2–10mm above the surface for the most reliable line detection.
• Turn the potentiometer while you hold the sensor over white, then over black, until the LED clearly switches between the two.
• Avoid direct sunlight, which contains IR and can confuse the sensor.
• Use black electrical tape on a white board or floor to make an easy test track.
• For a smooth line follower, use 2–5 sensors in a row.

Applications

• Line-following robots and smart cars
• Robot edge and table-fall detection
• Short-range obstacle detection
• Object counting on conveyors
• Motor RPM and rotation counting (with a black/white marker)
• Paper and object presence detection
• Robotics competitions and STEM projects

Works Great With

• Arduino Uno R3
• Arduino Sensor Shield V5.0
• L298N Motor Driver
• Robot Car Chassis Kit

Package Includes

• 1 × TCRT5000 IR Line Tracking Sensor Module