#include <Wire.h>
#include <Arduino.h>
#include <DHT.h>

#define PPM_PIN 4  // Pin connected to MQ135 sensor
#define DHT_PIN 5  // Pin connected to DHT22 sensor
#define DHT_TYPE DHT22

DHT dht(DHT_PIN, DHT_TYPE);

void setup() {
  Wire.begin(23, 22);
  Serial.begin(9600);
  Serial.println("Hello, ESP32!");
  dht.begin();
}

void loop() {
  // Read MQ135 sensor data
  int16_t ppmValue = analogRead(PPM_PIN);
  int mappedppmValue = (ppmValue / 4.095);
  Serial.print("PPM: ");
  Serial.println(mappedppmValue);

  // Read DHT22 sensor data
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Check if data is valid
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
  } else {
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" *C");
    Serial.print("Humidity: ");
    Serial.print(humidity);
    Serial.println(" %");
  }

  delay(1000); // Wait 1 second before taking next reading
}