Introduction

The 3-channel path tracing module is an infrared sensor array designed for line-following robots and surface tracking applications. It features three IR sensors that detect contrasting surfaces (typically black lines on white surfaces) and provides digital outputs for each channel.

Key Features

Technical Specifications

Pin Configuration

Pin	Function	Description
VCC	Power	3.3V-5V input
GND	Ground	Common ground
OUT1	Output 1	Left sensor output
OUT2	Output 2	Center sensor output
OUT3	Output 3	Right sensor output
LED	Indicator	Power LED (optional)

Wiring with Arduino

// Basic Connection:
// VCC  → Arduino 5V
// GND  → Arduino GND
// OUT1 → Digital Pin 2 (Left)
// OUT2 → Digital Pin 3 (Center)
// OUT3 → Digital Pin 4 (Right)

Basic Line Detection Code

const int leftPin = 2;
const int centerPin = 3;
const int rightPin = 4;

void setup() {
  pinMode(leftPin, INPUT);
  pinMode(centerPin, INPUT);
  pinMode(rightPin, INPUT);
  Serial.begin(9600);
}

void loop() {
  int left = digitalRead(leftPin);
  int center = digitalRead(centerPin);
  int right = digitalRead(rightPin);

  Serial.print("Left: "); Serial.print(left);
  Serial.print(" | Center: "); Serial.print(center);
  Serial.print(" | Right: "); Serial.println(right);
  
  delay(100);
}

Line Following Robot Logic

// Motor control pins
const int leftMotor = 5;
const int rightMotor = 6;

void setup() {
  // ... (previous sensor setup)
  pinMode(leftMotor, OUTPUT);
  pinMode(rightMotor, OUTPUT);
}

void loop() {
  int left = digitalRead(leftPin);
  int center = digitalRead(centerPin);
  int right = digitalRead(rightPin);

  if (center == LOW) {
    // On line - move forward
    analogWrite(leftMotor, 150);
    analogWrite(rightMotor, 150);
  }
  else if (left == LOW) {
    // Line to left - turn left
    analogWrite(leftMotor, 100);
    analogWrite(rightMotor, 200);
  }
  else if (right == LOW) {
    // Line to right - turn right
    analogWrite(leftMotor, 200);
    analogWrite(rightMotor, 100);
  }
  else {
    // No line detected - stop or search
    analogWrite(leftMotor, 0);
    analogWrite(rightMotor, 0);
  }
}

Calibration & Adjustment

void setup() {
  // ... (previous setup)
  Serial.println("Place sensor over line to test");
}

Troubleshooting