// Blynk credentials (from Blynk dashboard)
#define BLYNK_TEMPLATE_ID "TMPL3ma8D9ACv"
#define BLYNK_TEMPLATE_NAME "Assingment"
#define BLYNK_AUTH_TOKEN "7uxPQrIHdJ4W6LEs7U5Vo2lbhJ1F95uP"

#include <WiFi.h>                  // For WiFi connection
#include <DHT.h>                   // For DHT sensor
#include <BlynkSimpleEsp32.h>      // For Blynk cloud communication

// Pin definitions
#define DHTPIN 14                 // DHT22 data pin connected to GPIO13
#define DHTTYPE DHT22              // Sensor type
#define MQ2PIN 12                  // MQ2 analog pin connected to GPIO32

// WiFi credentials
char ssid[] = "Wokwi-GUEST";       // Wokwi simulator WiFi
char pass[] = "";                  // No password for Wokwi
char auth[] = BLYNK_AUTH_TOKEN;    // Blynk authentication token

DHT dht(DHTPIN, DHTTYPE);          // Initialize DHT sensor

void setup() {
  Serial.begin(115200);            // Start serial monitor
  delay(100);

  // Connect to WiFi
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());

  // Connect to Blynk
  Blynk.config(auth);
  Blynk.connect();

  // Start DHT sensor
  dht.begin();

  // MQ2 sensor needs 1 min warm-up
  delay(60000);
  Serial.println("MQ2 sensor warm-up complete.");
}

void loop() {
  Blynk.run();                     // Run Blynk
  readAndSendSensorData();        // Read and send data
  delay(2000);                     // Wait 2 seconds before next reading
}

// Function to read sensor values and send to Blynk
void readAndSendSensorData() {
  float temp = dht.readTemperature();     // Read temperature
  float hum = dht.readHumidity();         // Read humidity
  int gasValue = analogRead(MQ2PIN);      // Read gas sensor value

  // Check if sensor reading failed
  if (isnan(temp) || isnan(hum)) {
    Serial.println("DHT read failed");
    return;
  }

  // Show values in Serial Monitor
  Serial.printf("Temperature: %.2f °C\n", temp);
  Serial.printf("Humidity: %.2f %%\n", hum);
  Serial.printf("Gas Sensor Value: %d\n", gasValue);

  // Send values to Blynk
  Blynk.virtualWrite(V0, temp);       // Temperature - V0
  Blynk.virtualWrite(V1, hum);        // Humidity - V1
  Blynk.virtualWrite(V2, gasValue);   // Gas - V2
}