#define BLYNK_TEMPLATE_ID "TMPL383KxGRw7"
#define BLYNK_TEMPLATE_NAME "air quality monitoring system"
#define BLYNK_AUTH_TOKEN "yBjjuex-s_7mPNPJE8zOIEHgo9T2OOnH"

#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <BlynkSimpleEsp32.h>

// Blynk Auth Token
char auth[] = "yBjjuex-s_7mPNPJE8zOIEHgo9T2OOnH";

// Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";


// DHT Sensor
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// MQ135 Sensor
#define MQ135_PIN 36

// OLED
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Virtual Pins
#define VIRTUAL_PIN_TEMP V0
#define VIRTUAL_PIN_HUMIDITY V1
#define VIRTUAL_PIN_AIR_QUALITY V2

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

  // Initialize DHT sensor
  dht.begin();

  // Initialize OLED display
  if (!display.begin(SSD1306_PAGEADDR, SCREEN_WIDTH, SCREEN_HEIGHT)) {

    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.clearDisplay();

  // Connect to Wi-Fi and Blynk
  Blynk.begin(auth, ssid, pass);

  // Welcome message
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Blynk Connected!");
  display.display();
  delay(2000);
}

void loop() {
  Blynk.run(); // Run Blynk

  // Read sensor values

  float temperature = dht.readTemperature();
if (isnan(temperature)) {
  Serial.println("Failed to read temperature from sensor!");
} else {
  Serial.println(temperature);
}

  float humidity = dht.readHumidity();
  int mq135_value = analogRead(MQ135_PIN);

  // Send to Blynk
  Blynk.virtualWrite(VIRTUAL_PIN_TEMP, temperature);
  Blynk.virtualWrite(VIRTUAL_PIN_HUMIDITY, humidity);
  Blynk.virtualWrite(VIRTUAL_PIN_AIR_QUALITY, mq135_value);

  // Display on OLED
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Temp: ");
  display.print(temperature);
  display.print(" C");

  display.setCursor(0, 10);
  display.print("Humidity: ");
  display.print(humidity);
  display.print(" %");

  display.setCursor(0, 20);
  display.print("Air Quality: ");
  display.print(mq135_value);

  display.display();

  // Print to Serial Monitor
  Serial.print("Temperature: ");
  Serial.println(temperature);
  Serial.print("Humidity: ");
  Serial.println(humidity);
  Serial.print("Air Quality: ");
  Serial.println(mq135_value);

  delay(2000); // Adjust as needed
}