Line-Following Robot

Built during the Robotics track, this was a collaborative project involving two students. The robot uses two infra-red sensors to detect the boundary between a black line and white surface, adjusting motor speed to stay on course.

Hardware used

• Arduino Uno microcontroller
• L298N dual H-bridge motor driver
• 2× IR proximity sensors
• 2× DC gear motors + chassis kit
• 7.4V LiPo battery pack

How it works

Each sensor returns a HIGH signal when it detects white and LOW over black. A simple decision tree in the loop function steers the robot: both sensors on white = go straight, left sensor on black = turn left, right sensor on black = turn right.

void loop() {
  int leftVal  = digitalRead(LEFT_SENSOR);
  int rightVal = digitalRead(RIGHT_SENSOR);
  if (leftVal == HIGH && rightVal == HIGH) forward();
  else if (leftVal == LOW)  turnLeft();
  else if (rightVal == LOW) turnRight();
}