#define MQ2_ANA A1
#define MQ2_DIG 2

#include <Servo.h>

// Define pins
const int gasSensorPin = MQ2_ANA;  // Analog pin for gas sensor
const int buzzerPin = 7;           // Digital pin for buzzer
const int servoPin = 4;            // Digital pin for servo

// Threshold for gas detection
const int gasThreshold = 300;      // Adjust based on your sensor's sensitivity

Servo myServo;

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);

  // Initialize servo
  myServo.attach(servoPin);

  // Initialize pins
  pinMode(gasSensorPin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  // Initialize servo position
  myServo.write(0);  // Start position
}

void loop() {
  // Read gas sensor value
  int gasValue = analogRead(gasSensorPin);

  // Print the gas sensor value to the Serial Monitor
  Serial.print("Gas Sensor Value: ");
  Serial.println(gasValue);

  // Check if the gas level is above the threshold
  if (gasValue > gasThreshold) {
    // Rotate servo to 90 degrees
    myServo.write(90);

    // Turn on buzzer
    digitalWrite(buzzerPin, HIGH);
  } else {
    // Rotate servo back to 0 degrees
    myServo.write(0);

    // Turn off buzzer
    digitalWrite(buzzerPin, LOW);
  }

  // Small delay to avoid rapid triggering
  delay(500);
}