Portable Room Monitor

#include <Adafruit_CCS811.h>
#include <Nextion.h>
#include <DHT.h>
#include <WiFiManager.h>
#include <DNSServer.h>
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266HTTPClient.h>
#include <RTClib.h>
#include <Wire.h>
#include <SPI.h>
#include <SoftwareSerial.h>

/* Basic Initializations */

SoftwareSerial nex(D5,D6);

/* Nextion Display */
NexText t0 = NexText(0, 1, "t0");
NexText t1 = NexText(0, 2, "t1");
NexText t2 = NexText(0, 3, "t2");
NexText t3 = NexText(0, 4, "t3");
NexTouch *nex_listen_list[] = {
  NULL
};
/* CCS811 */
Adafruit_CCS811 ccs;
/* DHT22 */
#define DHTPIN D4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
float t,h;
int co2,voc;
/* NodeMCU WiFi Credentials */
const char *host = "**YOUR HOSTING NAME (IP OR DOMAIN NAME)***";   //IP address of server
WiFiManager wifiManager;
/* Setup Function that runs only once in the program */

void setup()
{
  /* Setting baud rate as 9600 */
  Serial.begin(9600);
  /* Initialise Nextion */
  nexInit();
  nex.begin(9600);
  /* Initialise DHT22 */
  dht.begin();
  /* Initialise CCS811 */
  if (!ccs.begin()) {
    Serial.println("Failed to start sensor! Please check your wiring.");
    while (1);
  }
  /* Initialise WiFI */
  //wifiManager.resetSettings();
}

/* Loop Function that runs always on loop in the program */

void loop()
{
  if (ccs.available()) {
    h = (dht.readHumidity()+0.00);
    t = (dht.readTemperature()+0.00);
    co2 = ccs.geteCO2();
    voc = ccs.getTVOC();
    if (!ccs.readData()) {
      /* Display on Nextion */
      if(co2==0 && voc==0)
      {
        //This helps to avoid sending 0 values of CCS811 sensor while intialising
        Serial.println("I am here");
        return;
      }
      else
      {
      nex.write(0xff);
      nex.write(0xff);
      nex.write(0xff);
      nex.print("t0.txt=");
      nex.print("\"" + String(t) + "\"");
      nex.write(0xff);
      nex.write(0xff);
      nex.write(0xff);
      nex.print("t1.txt=");
      nex.print("\"" + String(h) + "\"");
      nex.write(0xff);
      nex.write(0xff);
      nex.write(0xff);
      nex.print("t2.txt=");
      nex.print("\"" + String(co2) + "\"");
      nex.write(0xff);
      nex.write(0xff);
      nex.write(0xff);
      nex.print("t3.txt=");
      nex.print("\"" + String(voc) + "\"");
      nex.write(0xff);
      nex.write(0xff);
      nex.write(0xff);
      Serial.println(String(t)+","+String(h)+","+String(co2)+","+String(voc));
      /* Sending Data over WiFi */
      WifiData();
      }
      delay(180000);
    }
  }
}
void WifiData()
{
  wifiManager.autoConnect("***ANY NAME YOU WOULD LIKE TO NAME YOUR DEVICE HOTSPOT***");
  // if you get here you have connected to the WiFi
  Serial.println("Connected.");
  Serial.print("Connecting to ");
  Serial.println(host);
  WiFiClient client;
  const int httpPort = 80;
  if (!client.connect(host, httpPort))
  {
    Serial.println("Connection Failed");
    return;
  }
  String url1 = "/room.php?Temperature=" + String(t) + "&Humidity=" + String(h) + "&CO2=" + String(co2) + "&VOC=" + String(voc);
  Serial.print("Requesting URL: ");
  Serial.println(url1);
  client.print(String ("GET ") + url1 + " HTTP/1.1\r\n" + "Host: " + host + "\r\n" + "Connection: close\r\n\r\n");
  delay(500);
  while (client.available())
  {
    String line = client.readStringUntil('\r');
    Serial.print(line);
  }
  Serial.println();
  Serial.println("Closing Connection");
}