Project 2 - Measuring distance of an object using ultrasonic sensor (HC-SR04)

// Define the pins for the ultrasonic sensor

const int trigPin = 9;

const int echoPin = 10;

// Variables to store the distance measurement

long duration;

int distance;

void setup() {

// Initialize serial communication

Serial.begin(9600);

// Set trigPin as output and echoPin as input

pinMode(trigPin, OUTPUT);

pinMode(echoPin, INPUT);

}

void loop() {

// Clear the trigPin before sending the pulse

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

// Send a 10 microsecond pulse to trigger the sensor

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);

// Measure the duration of the pulse on the echoPin

duration = pulseIn(echoPin, HIGH);

// Calculate the distance based on the speed of sound (343m/s)

// and the duration of the pulse

distance = duration * 0.0343 / 2; // Divide by 2 as the sound travels round trip

// Print the distance to the serial monitor

Serial.print("Distance: ");

Serial.print(distance);

Serial.println(" cm");

// Delay before taking the next measurement

delay(1000);

}