// Include libraries
#include <MQ7.h>
#include <GSM.h>
#include <Servo.h>

// Define pins
#define MQ7_PIN 3
#define GSM_TX_PIN 1
#define GSM_RX_PIN 0
#define SERVO_PIN 11

// Initialize objects
MQ7 mq7(MQ7_PIN);
GSM gsm(GSM_TX_PIN, GSM_RX_PIN);
Servo servo;

// Define variables
int gasThreshold = 500; // Change this value according to your needs
int servoAngle = 0; // Initial servo angle
int servoDelay = 1000; // Delay for servo to move to desired angle
int gasValue = 0; // Variable to store gas sensor reading
bool gasDetected = false; // Flag to indicate if gas is detected

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  
  // Initialize GSM module
  gsm.initialize();
  
  // Attach servo to pin
  servo.attach(SERVO_PIN);
  
  // Set servo to initial angle
  servo.write(servoAngle);
}

void loop() {
  // Read gas sensor value
  gasValue = mq7.readGas();
  
  // Check if gas value is above threshold
  if (gasValue > gasThreshold) {
    // Gas detected, set flag to true
    gasDetected = true;
    
    // Send SMS using GSM module
    gsm.sendSMS("+917989784940", "Gas detected!");
    
    // Move servo to close off regulator
    servoAngle = 90; // Change this value according to your servo's range
    servo.write(servoAngle);
    
    // Wait for servo to move to desired angle
    delay(servoDelay);
  }