#include "DHT.h"

#define MQ135_pin 34  // CO2 Gas Sensor
#define MQ4_pin 35    // Methane Gas Sensor
#define DHT11_pin 2   // Temperature and Humidity Sensor

int MQ135_gas_RAW_Reading_CO2 = 0;
int MQ4_gas_RAW_Reading_Methane = 0;
float Temperature = 0;
float Humidity = 0;

DHT dht;

void setup() {
  Serial.begin(9600);
  initialize_Sensors();
}

void loop() {
  Read_Sensors_Data();
  show_Sensor_Data_on_Serial_Monitor();
}

void initialize_Sensors() {
  dht.setup(DHT11_pin);
  pinMode(MQ135_pin, INPUT);
  pinMode(MQ4_pin, INPUT);
}

void Read_Sensor_Data() {
  Humidity = dht.getHumidity();                       //0-100%
  Temperature = dht.getTemperature();                 //20-60°C
  MQ135_gas_RAW_Reading_CO2 = analogRead(MQ135_pin);  //0-4096
  MQ4_gas_RAW_Reading_Methane = analogRead(MQ4_pin);  //0-4096
}

void show_Sensor_Data_on_Serial_Monitor() {
  Serial.print("Humidity: ");
  Serial.print(Humidity);
  Serial.print(" [%]");
  Serial.print("Temperature: ");
  Serial.print(Temperature);
  Serial.print(" [°C]");
  Serial.print("Gas CO2: ");
  Serial.print(MQ135_gas_RAW_Reading_CO2);
  Serial.print(" [VoltageLevel]");
  Serial.print("Gas Methane: ");
  Serial.print(MQ4_gas_RAW_Reading_Methane);
  Serial.print(" [VoltageLevel]");
  Serial.println("-----------------------------");
}