#include <Arduino.h>

// Define pins
const int trigPin = 15;  
const int echoPin = 14;   
const int pirPin = 13;    
const int ledPin = 12;    
const int buzzerPin = 16; 

// Variables for distance measurement
long duration;
int distance;

void setup() {
  // Initialize serial communication
  Serial.begin(115200);

  // Initialize pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(pirPin, INPUT);
  pinMode(ledPin, OUTPUT);    
  pinMode(buzzerPin, OUTPUT); 
}

void loop() {
  // Check if motion is detected
  if (digitalRead(pirPin) == HIGH) {
    Serial.println("Motion detected!");

    // Trigger the HC-SR04 to measure distance
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Read the echo pin
    duration = pulseIn(echoPin, HIGH);
    
    // Calculate distance
    distance = duration * 0.0344 / 2; 

    if (distance < 100) { 
      Serial.print("No motion detected");
      Serial.print(distance);
      Serial.println(" cm");
      
      // Activate the LED
      digitalWrite(ledPin, LOW); 
      // Activate the Buzzer
      digitalWrite(buzzerPin, LOW); 
      delay(1000); 
      digitalWrite(ledPin, HIGH);  
      digitalWrite(buzzerPin, HIGH); 
    }
  } else {
    Serial.println("Object detected at ");
    digitalWrite(ledPin, HIGH); 
    digitalWrite(buzzerPin, HIGH); 
  }

  delay(1000); 
}