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

// Wi-Fi credentials
const char* ssid = "YourSSID";
const char* password = "YourPassword";

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

// Pin definitions
#define MQ135_PIN 34    // Simulated analog input for MQ135 sensor
#define DHT_PIN 4       // Pin for DHT sensor
#define DHTTYPE DHT11

DHT dht(DHT_PIN, DHTTYPE);

// Variables
WiFiClient client;

void setup() {
  Serial.begin(115200);

  // Initialize DHT sensor
  dht.begin();

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Connect to ThingSpeak
  ThingSpeak.begin(client);
}

void loop() {
  // Read sensors
  float airQuality = analogRead(MQ135_PIN); // Simulated sensor output using a potentiometer
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  if (!isnan(temp) && !isnan(hum)) {
    Serial.print("Temperature: ");
    Serial.print(temp);
    Serial.print("°C, Humidity: ");
    Serial.print(hum);
    Serial.print("%, Air Quality: ");
    Serial.println(airQuality);

    // Send data to ThingSpeak
    ThingSpeak.setField(1, temp);
    ThingSpeak.setField(2, hum);
    ThingSpeak.setField(3, airQuality);
    int status = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
    if (status == 200) {
      Serial.println("Data sent to ThingSpeak");
    } else {
      Serial.println("Failed to send data to ThingSpeak");
    }
  }

  // Delay for 20 seconds
  delay(20000);
}