#include <Servo.h>


const int gasSensorPin = A4;     
const int greenLedPin  = 8;      
const int redLedPin    = 7;      
const int buzzerPin    = 9;     
const int servoPin     = 3;      

const int gasThreshold = 800;   
Servo myServo;

void setup() {
  pinMode(greenLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(gasSensorPin, INPUT);
  myServo.attach(servoPin);
  myServo.write(0);

  Serial.begin(9600);
}

void loop() {
  int gasValue = analogRead(gasSensorPin);
  Serial.print("Gas Sensor Value: ");
  Serial.println(gasValue);

  if (gasValue > gasThreshold) {
   
    digitalWrite(redLedPin, HIGH);
    digitalWrite(greenLedPin, LOW);
    
    
    tone(buzzerPin, 10); 
    
    myServo.write(180); 
  } else {
    
    digitalWrite(redLedPin, LOW);
    digitalWrite(greenLedPin, HIGH);
    
    
    noTone(buzzerPin); 
    
    myServo.write(0); 
  }

  delay(500); 
}