LESSON 13 - Real Time Clock (RTC) with DS3231Module and Arduino Uno

In this lesson, I've explained Real Time clock  with serial i2c module (Figure 1), Arduino UNO and DS3231 module (Figure 2).

Figure 1 - Serial I2C LCD Module

Figure 2 - DS3231 Module

DS3231 Module

The DS3231 is a low-cost, highly accurate Real Time Clock which can maintain hours, minutes and seconds, as well as, day, month and year information. Also, it has automatic compensation for leap-years and for months with fewer than 31 days. The module can work on either 3.3 or 5 V which makes it suitable for many development platforms or microcontrollers. The battery input is 3V and a typical CR2032 3V battery can power the module and maintain the information for more than a year.

Module pins are connected with Arduino as follows;

SDA (A4); SCL(A5); VCC(5V veya Vin); GND(GND)

Figure 3 - Real Time Clock Circuit

The Program of Arduino UNO

#include <Wire.h>                // For the i2c devices (i2C modülü için)

#include <LiquidCrystal_I2C.h>  // For the LCD Display (LCD Ekran için)

#include "RTClib.h"             //  For Real Time Clock (Gerçek Zamanlı saat için) 

RTC_DS3231 rtc;

char daysOfTheWeek[7][12] = {"Paz", "Pzt", "Sal", "Car", "Per", "Cum", "Cmt"}; //Days of week (Haftanın günleri)

LiquidCrystal_I2C lcd(0x27,16,2);//A4 and A5 Arduino port for SLC adn SLA

void setup()

{

  Wire.begin();

  lcd.begin();

}

void loop()

{

    DateTime now = rtc.now(); //Now (Şimdiki Tarih ve Zaman)

    lcd.backlight();

    // Date(Tarih)

    lcd.setCursor(0,0);

    lcd.print(now.day(), DEC);

    lcd.print('/');

    lcd.print(now.month(), DEC);

    lcd.print('/');

    lcd.print(now.year(), DEC);

    

    //Days of week (Haftanın Günü)

    lcd.setCursor(11,0);

    lcd.print(daysOfTheWeek[now.dayOfTheWeek()]);

   

    //Time (Saat)

    lcd.setCursor(0,1);

    lcd.print(now.hour(), DEC);

    lcd.print(':');

    lcd.print(now.minute(), DEC);

    lcd.print(':');

    lcd.print(now.second(), DEC);

    

    delay(1000); // 1 second (1 Saniye)

}

Project Files

• Arduino UNO Program rtc.ino
• LiquidCrystal_I2C.h
• RTClib.h

Video of Lesson