Building Our First Arduino Line Follower Robot#

Posted on January 1, 2024

This was our crew’s first collaborative robot build - a simple but effective line-following robot that taught us the fundamentals of sensor integration, motor control, and basic robotics programming.

What We Built#

A small, two-wheeled robot that follows a black line on a white surface using infrared sensors. It’s the perfect first project for anyone getting into robotics.

Components Used#

  • Arduino Uno
  • 2x IR sensors (TCRT5000)
  • 2x DC motors with wheels
  • L298N motor driver
  • 9V battery
  • Chassis (3D printed)

The Build Process#

Step 1: Assembly#

We started with a simple 3D printed chassis and mounted the motors, sensors, and electronics. The key was getting the IR sensors positioned correctly - they need to be close to the ground but not touching.

Step 2: Wiring#

The wiring was straightforward:

  • IR sensors → Arduino analog pins
  • Motor driver → Arduino digital pins
  • Power distribution from battery

Step 3: Programming#

The logic is simple but effective:

  1. Read sensor values
  2. Determine if robot is on or off the line
  3. Adjust motor speeds accordingly

Code Highlights#

void loop() {
  int leftSensor = analogRead(LEFT_SENSOR);
  int rightSensor = analogRead(RIGHT_SENSOR);
  
  if (leftSensor < THRESHOLD && rightSensor < THRESHOLD) {
    // Both sensors on white - go straight
    goForward();
  } else if (leftSensor > THRESHOLD) {
    // Left sensor on black - turn left
    turnLeft();
  } else if (rightSensor > THRESHOLD) {
    // Right sensor on black - turn right
    turnRight();
  }
}

Lessons Learned#

  1. Sensor positioning is crucial - even a few millimeters can make a huge difference
  2. Battery voltage matters - our robot behaved differently as the battery drained
  3. Simple algorithms often work better - we tried complex PID control but basic on/off logic was more reliable

What’s Next#

This robot is now our test platform for new sensors and algorithms. We’re planning to add:

  • Bluetooth control
  • Obstacle avoidance
  • Speed control
  • Data logging

Want to build your own? Check out our GitHub repo for complete schematics and code.