#include <WiFi.h>
#include "ThingSpeak.h" // always include thingspeak header file after other header files and custom macros


#define WIFI_SSID "Wokwi-GUEST"		// replace MySSID with your WiFi network name
#define WIFI_PASSWORD ""	// replace MyPassword with your WiFi password

#define SECRET_CH_ID 2462866			// replace 0000000 with your channel number
#define SECRET_WRITE_APIKEY "SN6DIERM7PMWT596"   //replace XYZ with your channel write API Key

#define MQ2 34 // define MQ2 analog pin

#define LED 14

WiFiClient  client;

unsigned long myChannelNumber = SECRET_CH_ID;
const char * myWriteAPIKey = SECRET_WRITE_APIKEY;

int gas;
unsigned long dataMillis = 0;

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

  pinMode(MQ2, INPUT);
 
  pinMode(LED, OUTPUT);
  digitalWrite(LED, LOW);

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Connecting to Wi-Fi");
  while (WiFi.status() != WL_CONNECTED)
  {
      Serial.print(".");
      delay(300);
  }
  Serial.println();
  Serial.print("Connected with IP: ");
  Serial.println(WiFi.localIP());
  Serial.println();

  ThingSpeak.begin(client);  // Initialize ThingSpeak
}

void loop() {

  gas = analogRead(MQ2);


  Serial.printf("Gas: %d\n", gas);


  ThingSpeak.setField(3, gas);

  if (millis() - dataMillis < 20000)
  {
    int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
    if(x == 200){
      Serial.println("Channel update successful.");
    }
    else {
      Serial.println("Problem updating channel. HTTP error code " + String(x));
    }  
  }

  if(gas>100){
    digitalWrite(LED, HIGH);
    delay(100);
    digitalWrite(LED, LOW);
    delay(100);
  }
    else{
    digitalWrite(LED, LOW);
    delay(100);
      
    }
  }