Object Detection with Alarm

In this project, we are creating an Object Detection System that uses an ultrasonic sensor to measure distance and triggers an LED and a buzzer when an object comes too close.

Components Required

Arduino UNO

Ultrasonic Sensor

Buzzer

LED

220Ω Resistor

Jumper Wires

Circuit Diagram

Arduino Program Code

Download the Arduino Program Code for the Object Detection System with Alarm.

// Pin Definitions
#define TRIG_PIN 9
#define ECHO_PIN 8
#define LED_PIN 2
#define BUZZER_PIN 3

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  long duration;
  int distance;

  // Send a short pulse from TRIG
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read the time for the echo
  duration = pulseIn(ECHO_PIN, HIGH);

  // Convert time to distance in cm
  distance = duration * 0.034 / 2;

  // Print distance in Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // If object is closer than 10 cm
  if (distance <= 10) {
    digitalWrite(LED_PIN, HIGH);      // Turn ON LED
    digitalWrite(BUZZER_PIN, HIGH);   // Turn ON Buzzer
  } else {
    digitalWrite(LED_PIN, LOW);       // Turn OFF LED
    digitalWrite(BUZZER_PIN, LOW);    // Turn OFF Buzzer
  }

  delay(200);  // Small delay before next reading
}

Output