#include <WiFi.h>
#include "ThingSpeak.h"

// WiFi credentials
const char* ssid = "YOUR_WIFI_NAME";
const char* password = "YOUR_WIFI_PASSWORD";

// ThingSpeak credentials
unsigned long myChannelNumber = YOUR_CHANNEL_ID;
const char * myWriteAPIKey = "YOUR_API_KEY";

// WiFi + ThingSpeak client
WiFiClient client;

// MQ-2 sensor pin
const int gasSensorPin = 34; // ADC pin

void setup() {
  Serial.begin(115200);
    WiFi.begin(ssid, password);
    
      Serial.print("Connecting to WiFi");
        while (WiFi.status() != WL_CONNECTED) {
            delay(500);
                Serial.print(".");
                  }
                    Serial.println("\nWiFi Connected!");
                    
                      ThingSpeak.begin(client);
                      }
                      
                      void loop() {
                        // Read gas sensor value
                          int sensorValue = analogRead(gasSensorPin);
                            float voltage = sensorValue * (3.3 / 4095.0); // convert ADC to voltage
                            
                              Serial.print("Gas Sensor Value: ");
                                Serial.println(sensorValue);
                                  Serial.print("Voltage: ");
                                    Serial.println(voltage);
                                    
                                      // Send data to ThingSpeak
                                        int httpCode = ThingSpeak.writeField(myChannelNumber, 1, sensorValue, myWriteAPIKey);
                                        
                                          if (httpCode == 200) {
                                              Serial.println("Data sent to ThingSpeak successfully!");
                                                } else {
                                                    Serial.println("Error sending data: " + String(httpCode));
                                                      }
                                                      
                                                        delay(20000); // ThingSpeak requires at least 15 sec delay
                                                        }void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}