Arduino Maker Series Under 1000: Line Following Robot

Welcome to the Arduino Maker Series Under 1000! 🤖 Today, we are building a fun and practical Line Following Robot that autonomously follows a black line on a white surface. This project is perfect for beginners and makers interested in robotics, sensors, and automation.

Introduction
Required Hardware
Arduino IDE Setup
Wiring the Components
Arduino Code
How It Works
Testing Your Robot
Advanced Modifications
Common Issues and Troubleshooting
Learning Insights
Conclusion

1. Introduction

A line following robot uses infrared (IR) sensors to detect and follow a line on the ground, usually black tape on a white surface. The robot adjusts its motors to stay on track, allowing it to navigate predefined paths. By building this project, you will learn:

How IR sensors detect contrast between surfaces
Controlling motor direction using Arduino
Basic robotics logic for line following
Practical troubleshooting and sensor calibration

2. Required Hardware

Arduino Uno (~₹500)
2 x DC Motors with Wheels (~₹200)
Motor Driver Module (L298N) (~₹150)
IR Sensor Module (2–3 sensors) (~₹150)
Jumper Wires & Breadboard (~₹100)
Chassis / Frame (~₹200)
Battery Pack 6–7.4V (~₹150)

3. Arduino IDE Setup

Install Arduino IDE on your PC.
Connect the Arduino Uno via USB.
Go to Tools > Board and select Arduino Uno.
Go to Tools > Port and select the correct COM port.

4. Wiring the Components

Follow these wiring steps carefully:

IR Sensors: VCC → 5V, GND → GND, Output pins → Arduino Digital Pins 2 and 3
L298N Motor Driver: IN1 → D4, IN2 → D5 (Left motor); IN3 → D6, IN4 → D7 (Right motor)
Motors → L298N Output terminals
Battery pack → L298N VCC and GND

5. Arduino Code

Upload this code to your Arduino:

#define LEFT_SENSOR 2
#define RIGHT_SENSOR 3
#define IN1 4
#define IN2 5
#define IN3 6
#define IN4 7

void setup() {
  pinMode(LEFT_SENSOR, INPUT);
  pinMode(RIGHT_SENSOR, INPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void loop() {
  int leftValue = digitalRead(LEFT_SENSOR);
  int rightValue = digitalRead(RIGHT_SENSOR);

  if(leftValue == LOW && rightValue == LOW){
    // Move forward
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
  }
  else if(leftValue == HIGH && rightValue == LOW){
    // Turn right
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);
    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
  }
  else if(leftValue == LOW && rightValue == HIGH){
    // Turn left
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
    digitalWrite(IN3, LOW);
    digitalWrite(IN4, HIGH);
  }
  else{
    // Stop
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, LOW);
    digitalWrite(IN3, LOW);
    digitalWrite(IN4, LOW);
  }
}

6. How It Works

The IR sensors detect the black line by sensing the difference in reflectivity between the black tape and white surface. Arduino reads the sensor values and adjusts motor direction accordingly. If both sensors detect white (LOW), the robot moves forward. If left sensor detects black (HIGH), the robot turns right, and vice versa. If both sensors detect black, the robot stops. This simple logic allows the robot to follow a track autonomously.

7. Testing Your Robot

Place the robot on a black line track.
Power on the Arduino and motors.
Observe the robot following the line smoothly.
Adjust IR sensor sensitivity if needed (some modules have potentiometers).
Test turns and straight paths to ensure accuracy.

8. Advanced Modifications

Use 3–5 IR sensors for smoother navigation.
Integrate obstacle detection with ultrasonic sensors.
Connect to Bluetooth or Wi-Fi to monitor movement remotely.
Create a maze-solving algorithm for robotics competitions.

9. Common Issues and Troubleshooting

Robot not following line: Check sensor alignment and black tape quality.
Motors not running: Verify motor driver connections and power supply.
Robot turning incorrectly: Adjust sensor positions or sensitivity.
Arduino not responding: Ensure correct COM port and uploaded code.

10. Learning Insights

Learn autonomous control using sensors and Arduino logic.
Understand motor driver interfacing without PWM speed control.
Gain experience troubleshooting sensors and wiring issues.
Develop problem-solving skills for robotics challenges.
Expand into advanced robotics projects like obstacle avoidance or IoT integration.

11. Conclusion

This Line Following Robot project is a perfect addition to the Arduino Maker Series Under 1000. It’s affordable, educational, and fun for beginners and hobbyists. You can further extend it into obstacle-avoiding robots, maze solvers, or even fully autonomous vehicles for robotics competitions.

By Kaushal Haladi

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