Robotics is an exciting field that combines various disciplines, including electronics, mechanics, and programming, to create machines that can perform tasks autonomously or semi-autonomously. Arduino, an open-source electronics platform, is a popular choice for hobbyists and engineers alike to prototype and develop robotic projects due to its simplicity and versatility. This article will guide you through creating a simple robotic project using Arduino, providing practical examples and sample codes.

Examples:

1. Building a Basic Line-Following Robot:

A line-following robot is a classic beginner robotics project. It uses sensors to detect and follow a line drawn on the floor.

Components Needed:

• Arduino Uno
• Motor driver module (L298N)
• Two DC motors with wheels
• Chassis for mounting components
• Line tracking sensors (IR sensors)
• Battery pack
• Connecting wires

Sample Code:

#define LEFT_SENSOR_PIN A0
#define RIGHT_SENSOR_PIN A1
#define MOTOR_LEFT_FORWARD 5
#define MOTOR_LEFT_BACKWARD 6
#define MOTOR_RIGHT_FORWARD 9
#define MOTOR_RIGHT_BACKWARD 10

void setup() {
  pinMode(LEFT_SENSOR_PIN, INPUT);
  pinMode(RIGHT_SENSOR_PIN, INPUT);
  pinMode(MOTOR_LEFT_FORWARD, OUTPUT);
  pinMode(MOTOR_LEFT_BACKWARD, OUTPUT);
  pinMode(MOTOR_RIGHT_FORWARD, OUTPUT);
  pinMode(MOTOR_RIGHT_BACKWARD, OUTPUT);
}

void loop() {
  int leftSensorValue = analogRead(LEFT_SENSOR_PIN);
  int rightSensorValue = analogRead(RIGHT_SENSOR_PIN);

  if (leftSensorValue < 500 && rightSensorValue < 500) {
    // Move forward
    digitalWrite(MOTOR_LEFT_FORWARD, HIGH);
    digitalWrite(MOTOR_LEFT_BACKWARD, LOW);
    digitalWrite(MOTOR_RIGHT_FORWARD, HIGH);
    digitalWrite(MOTOR_RIGHT_BACKWARD, LOW);
  } else if (leftSensorValue > 500) {
    // Turn right
    digitalWrite(MOTOR_LEFT_FORWARD, HIGH);
    digitalWrite(MOTOR_LEFT_BACKWARD, LOW);
    digitalWrite(MOTOR_RIGHT_FORWARD, LOW);
    digitalWrite(MOTOR_RIGHT_BACKWARD, LOW);
  } else if (rightSensorValue > 500) {
    // Turn left
    digitalWrite(MOTOR_LEFT_FORWARD, LOW);
    digitalWrite(MOTOR_LEFT_BACKWARD, LOW);
    digitalWrite(MOTOR_RIGHT_FORWARD, HIGH);
    digitalWrite(MOTOR_RIGHT_BACKWARD, LOW);
  }
}

This code reads the values from the line tracking sensors and controls the motors to follow a line. The robot moves forward when both sensors detect the line, turns right when the left sensor detects the line, and turns left when the right sensor detects the line.

2. Creating a Simple Obstacle-Avoiding Robot:

An obstacle-avoiding robot can navigate around obstacles using ultrasonic distance sensors.

Components Needed:

• Arduino Uno
• Motor driver module (L298N)
• Two DC motors with wheels
• Chassis
• Ultrasonic distance sensor (HC-SR04)
• Battery pack
• Connecting wires

Sample Code:

#define TRIG_PIN 12
#define ECHO_PIN 11
#define MOTOR_LEFT_FORWARD 5
#define MOTOR_LEFT_BACKWARD 6
#define MOTOR_RIGHT_FORWARD 9
#define MOTOR_RIGHT_BACKWARD 10

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(MOTOR_LEFT_FORWARD, OUTPUT);
  pinMode(MOTOR_LEFT_BACKWARD, OUTPUT);
  pinMode(MOTOR_RIGHT_FORWARD, OUTPUT);
  pinMode(MOTOR_RIGHT_BACKWARD, OUTPUT);
}

long readDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  long distance = readDistance();

  if (distance < 20) {
    // Obstacle detected, turn right
    digitalWrite(MOTOR_LEFT_FORWARD, HIGH);
    digitalWrite(MOTOR_LEFT_BACKWARD, LOW);
    digitalWrite(MOTOR_RIGHT_FORWARD, LOW);
    digitalWrite(MOTOR_RIGHT_BACKWARD, LOW);
    delay(500);
  } else {
    // Move forward
    digitalWrite(MOTOR_LEFT_FORWARD, HIGH);
    digitalWrite(MOTOR_LEFT_BACKWARD, LOW);
    digitalWrite(MOTOR_RIGHT_FORWARD, HIGH);
    digitalWrite(MOTOR_RIGHT_BACKWARD, LOW);
  }
}

This code uses an ultrasonic sensor to measure the distance to the nearest obstacle. If the robot detects an obstacle within 20 cm, it turns right; otherwise, it moves forward.