Adding a Real Time Clock to the Basic Weather Station

//Basic Weather Station Using D1 Mini pro 10/13/19
//Real Time Clock added 10/26/19
//https://KM4NMP.com/
//For the I2C LCD library used and installation instructions use link below
//https://randomnerdtutorials.com/esp32-esp8266-i2c-lcd-arduino-ide/
//For the DHTesp Library use link below
//https://github.com/beegee-tokyo/DHTesp/archive/master.zip
//Real Time Clock Library used is RTClib by Adafruit. to install search in
//the Library Manager and click install

#include "DHTesp.h"
#include "RTClib.h"
#include <LiquidCrystal_I2C.h>

RTC_DS3231 rtc;

int lcdColumns = 16;
int lcdRows = 2;
bool state=0;
unsigned long previousMillis = 0;
const long interval = 2000;


LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);

DHTesp dht;

void setup() {
  

#ifndef ESP8266
  while (!Serial); // for Leonardo/Micro/Zero
#endif

Serial.begin(9600);
  
  dht.setup(14, DHTesp::DHT22);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);  
  lcd.print("KM4NMP.com");

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }


    //SET DATE AND TIME TO COMPILE TIME
    //rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    //rtc.adjust(DateTime(2019, 10, 26, 3, 0, 0));
  
    DateTime now = rtc.now();
    lcd.setCursor(11, 0);
    if (now.hour() >= 10 ) {      //check hours if 10 or above and print hours
      lcd.print(now.hour(), DEC);
      lcd.print(':');
    }
    
    if (now.hour() <= 9) {        //check hours if 9 or below
      lcd.print("0");             //if needed 0 is printed before hours
      lcd.print(now.hour(), DEC);
      lcd.print(':');
    }

    if (now.minute() >=10) {          //checks if minutes are 10 or above 
      lcd.print(now.minute(), DEC);
    }

     if (now.minute() <=9) {         //checks if minutes are 9 or below
      lcd.print("0");                //if needed prints 0 before minutes
      lcd.print(now.minute(), DEC);
    }

}

void loop() {
    unsigned long currentMillis = millis();
    DateTime now = rtc.now();
  
    lcd.setCursor(11, 0);
    if (now.hour() >= 10 ) {
      lcd.print(now.hour(), DEC);
      lcd.print(':');
    }
    
    if (now.hour() <= 9) {
      lcd.print("0");
      lcd.print(now.hour(), DEC);
      lcd.print(':');
    }

    if (now.minute() >=10) {
      lcd.print(now.minute(), DEC);
    }

     if (now.minute() <=9) {
      lcd.print("0");
      lcd.print(now.minute(), DEC);
    }
  
  
  if (currentMillis - previousMillis >= interval){ //checks time elapsed since last read 
    float h = dht.getHumidity();                   //get humidity
    float t = dht.getTemperature();                //get temperature
    float f = t*9/5+32;                            //change temp to F
    lcd.setCursor(0, 1);
    lcd.print(f);                                  //prints temp
    lcd.print((char)223);                          //character for derees
    lcd.print("F   ");
    lcd.print(h);                                  //prints humidity
    lcd.print((char)37);                           //special character for%
    previousMillis = currentMillis;                // resets time of last read
  }
    
  
}