// PIR sensor connected to pin 7
const int pirPin = 7;
// LED connected to pin 12
const int ledPin = 12;
// Variable to store PIR sensor status (motion detected or not)
int pirState = LOW;
int prevPirState = LOW;

void setup() {
  // Begin communication with the computer at a baud rate of 9600
  Serial.begin(9600);
  
  // Set the PIR sensor pin as input
  pinMode(pirPin, INPUT);
  
  // Set the LED pin as output
  pinMode(ledPin, OUTPUT);
  
  // Welcome message for user interaction
  Serial.println("PIR Sensor is warming up...");
  delay(5000);  // Wait for PIR sensor to stabilize (common with PIR sensors)
  Serial.println("PIR Sensor ready! Waiting for motion...");
}

void loop() {
  // Read the value from the PIR sensor (HIGH when motion is detected, LOW otherwise)
  pirState = digitalRead(pirPin);

  if (pirState == HIGH) {
    // If motion is detected
    if (prevPirState == LOW) {
      // Change in state detected (motion started)
      Serial.println("Motion detected! 🚶‍♂️");
      
      // Turn on the LED
      digitalWrite(ledPin, HIGH);
      
      // Update the previous state
      prevPirState = HIGH;
    }
  } else {
    // If no motion is detected
    if (prevPirState == HIGH) {
      // Change in state detected (motion stopped)
      Serial.println("Motion ended! 🌙");
      
      // Turn off the LED
      digitalWrite(ledPin, LOW);
      
      // Update the previous state
      prevPirState = LOW;
    }
  }

  // Small delay to stabilize readings
  delay(200);
}