Arduino Uno Code for an 8-Array IR Sensor in Line Follower Robot

To create a line follower robot using an Arduino Uno with an 8-array IR sensor, you'll need to read the sensor values and control the motors based on those readings. This article provides a simple example of how to achieve this.

Components Needed

Arduino Uno 8-array IR sensor or multiple IR sensors Motor driver like L298N or L293D DC motors Chassis for the robot Power supply batteries Wiring

Connecting the Components

Make sure to connect the 8-array IR sensor outputs to the Arduino's digital pins. For example:

IR sensor outputs to pins 2 to 9 on the Arduino. Motor driver inputs to Arduino pins for example pins 10, 11 for the left motor, and 12, 13 for the right motor.

Sample Code

Here's a basic code example for a line-following robot using an 8-array IR sensor:

// Define pin numbers
const int sensorPins[8]  {2, 3, 4, 5, 6, 7, 8, 9}; // IR sensor pins
const int motorLeftForward  10; // Left motor forward
const int motorLeftBackward  11; // Left motor backward
const int motorRightForward  12; // Right motor forward
const int motorRightBackward  13; // Right motor backward
void setup() {
    // Initialize motor pins as outputs
    pinMode(motorLeftForward, OUTPUT);
    pinMode(motorLeftBackward, OUTPUT);
    pinMode(motorRightForward, OUTPUT);
    pinMode(motorRightBackward, OUTPUT);
    // Initialize sensor pins as inputs
    for (int i  0; i  8; i  ) {
        pinMode(sensorPins[i], INPUT);
    }
}
void loop() {
    int sensorValues[8];
    // Read sensor values
    for (int i  0; i  8; i  ) {
        sensorValues[i]  digitalRead(sensorPins[i]);
    }
    // Determine motor actions based on sensor readings
    if (sensorValues[0]  LOW  sensorValues[1]  LOW  sensorValues[2]  LOW) {
        // Move forward
        moveForward();
    } else if (sensorValues[1]  LOW  sensorValues[2]  LOW) {
        // Slightly turn right
        turnRight();
    } else if (sensorValues[3]  LOW  sensorValues[4]  LOW) {
        // Slightly turn left
        turnLeft();
    } else if (sensorValues[7]  LOW) {
        // Hard turn left
        hardTurnLeft();
    } else if (sensorValues[0]  LOW) {
        // Hard turn right
        hardTurnRight();
    } else {
        // Stop if no line is detected
        stop();
    }
}
void moveForward() {
    digitalWrite(motorLeftForward, HIGH);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, HIGH);
    digitalWrite(motorRightBackward, LOW);
}
void turnRight() {
    digitalWrite(motorLeftForward, HIGH);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, LOW);
    digitalWrite(motorRightBackward, LOW);
}
void turnLeft() {
    digitalWrite(motorLeftForward, LOW);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, HIGH);
    digitalWrite(motorRightBackward, LOW);
}
void hardTurnLeft() {
    digitalWrite(motorLeftForward, LOW);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, HIGH);
    digitalWrite(motorRightBackward, LOW);
}
void hardTurnRight() {
    digitalWrite(motorLeftForward, HIGH);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, LOW);
    digitalWrite(motorRightBackward, LOW);
}
void stop() {
    digitalWrite(motorLeftForward, LOW);
    digitalWrite(motorLeftBackward, LOW);
    digitalWrite(motorRightForward, LOW);
    digitalWrite(motorRightBackward, LOW);
}

Explanation

Sensor Reading: The code reads the values from the 8 IR sensors. The sensors output LOW when they detect a line (black surface) and HIGH when they detect the ground (white surface). Motor Control: Depending on the sensor readings, the robot will move forward, turn left, turn right, or stop. Movement Logic: The robot uses simple conditions to decide how to react based on which sensors detect the line.

Tips

Tune the logic based on your specific sensor readings and the characteristics of your robot. You may want to implement additional functionality like PID control for smoother line following. Test and adjust the thresholds based on your environment and surface.

This code should provide a good starting point for your line-following robot project!