Back to Step by Step Course by Robojax

Lesson 99: Real-Time Cloick DS3231 to build LCD and LED Clock

Please select other codes for this lecture from the links below.

Related or required files and link to this lesson

Part 13: Clock and Timers

This code (99-1) is part of a lesson on using DS3231 Real-Time Clock module with Arduino.Please watch video for full details.

  • 00:00 Introduction
  • 04:11 DS3231 Datasheet
  • 05:07 DS3231 Wiring
  • 06:38 Simple DS3231 Clock code and library
  • 10:05 DS3231 Code using Alarm
  • 14:07 Running DS3231 Clock code demonstration
  • 17:49 Alarm Buzzer and LED wiring for DS3231, code and demo
  • 22:21 LCD Clock using DS3231
  • 23:57 LCD Clock Code for Arduino
  • 28:43 Building Unlimited Alarm using DS3231 clock module
  • 29:38 Unlimited alarm wiring diagram
  • 31:29 DS3231 using Alarm with relay and AC bulb wiring
  • 31:59 DS3231 Unlimited Alarm Arduino code
  • 34:38 Demonstration of Unlimited Alarm with reset push button
  • 35:40 LED Clock using DS3231 and HT16K33
  • 38:45 LED Clock code explained
  • 50:38 LED Clock Demonstration and settings

 * Lesson 99: LCD Clock using Arudino and DS3231 RTC module
 * Full video details:
 * In this lesson we have the following codes:
 * 1-Basic DS3231 to display on serial monitor
 * 2-Using Larm feature of the DS3231
 * 3-LCD Clock
 * 4-4 Digit LED Clock
 * 5-Unlimited Alarms using DS3231 with reset push button
 * This code is part of Arduino Step by Step Course which starts here:
 * for library of this code visit
If you found this tutorial helpful, please support me so I can continue creating 
content like this. Make a donation using PayPal by credit card
 * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <>.

  DS3231: Real-Time Clock. Simple example
  Read more:
  (c) 2014 by Korneliusz Jarzebski

#include <Wire.h>
#include <DS3231.h>

DS3231 clock;
RTCDateTime dt;

void setup()

  // Initialize DS3231
  Serial.println("Initialize DS3231");;

  // Set sketch compiling time
  clock.setDateTime(__DATE__, __TIME__);

void loop()
  dt = clock.getDateTime();

  // For leading zero look to DS3231_dateformat example

  Serial.print("Raw data: ");
  Serial.print(dt.year);   Serial.print("-");
  Serial.print(dt.month);  Serial.print("-");
  Serial.print(;    Serial.print(" ");
  Serial.print(dt.hour);   Serial.print(":");
  Serial.print(dt.minute); Serial.print(":");
  Serial.print(dt.second); Serial.println("");


The least I expect from you is to give the video a thumbs up and subscribe to my channel. I appreciate it. I have spent hundreds of hours making these lectures and writing code. You don't lose anything by subscribing to my channel. Your subscription is a stamp of approval for my videos, helping more people find them and, in turn, helping me. Thank you!

If you found this tutorial helpful, please support me so I can continue creating content like this. support me via PayPal

**** AFFILIATE PROGRAM **** We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.

Right Side