Build Simple digital clock using Arduino DS3107

Project Video
Project Details

Using this code shown in the video, we build a digital clock using seven segment display wiht HT16K33 module and DS1307 Real time clock
module with Arduino.

Libraries needed for this project

1-DS1307 RTClib library (and watch video instruction)
2-HT16K33 Library (and watch video instruction)
Both libraries are available for download from links below.

Chapters in this video

  • 00:38 Introduction
  • 01:51 Wiring explained
  • 03:16 Arduino code explained
  • 13:19 Demonstration of all features
Project Images
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Project Code


/*
 * file: DS1307_HT16K33_clock_display
 * Digital clock using DS1307 Real Time clock module and Arduino
 * Displays time on 4 digits seven segment dispaly HT16K33
 * Used DS1307 library and HT16K33 library below
 * watch video instruction: https://youtu.be/JUcskPLro4U
 * 
 * Must watch two videos
 * Introduction to DS1307: https://youtu.be/-I1nReV_oZg
 * Introduction to HT16K33: https://youtu.be/tEwWsbHQA5Q
 * 
 * Written by Ahmad Shamshiri on Feb 07, 2021 in Ajax, Ontario, Canada
 * www.Robojax.com
 * 
  * 
 * 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 Robojax.com
    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
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    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 .
  
  DS1307: RTCLib from Adafruit
   https://github.com/adafruit/RTClib/   

  HT16k33 library
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.0
// PURPOSE: demo
//     URL: http://www.adafruit.com/products/1002
//     URL: https://github.com/RobTillaart/HT16K33
  
*/
//DateTime (uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t min, uint8_t sec)

#include 
#include "RTClib.h"

RTC_DS1307 rtc;

#include "HT16K33.h"
HT16K33  seg(0x70);//initialize the display with 0x70 I2C address

//watch video for settings details and demo https://youtu.be/JUcskPLro4U
bool showSecond = false;//show or hide seconds. set to false to not show
unsigned int secondDisplayEvery=5000;//show seconds every 10 seconds
unsigned int secondBlinkCount=6;//show 3 blinks of second 
unsigned int secondDisplayDuration =5000;//for how long seconds should be shown (in milliseonds)
bool showLeadingZero =false;
bool showSecondNoBlink=true;//just count senconds no blink

unsigned long rememberTime = millis();
void showSeconds1();
void showSeconds2();

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup () {
  while (!Serial); // for Leonardo/Micro/Zero


  Serial.begin(9600);
  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  if (! rtc.isrunning()) {
    Serial.println("RTC is NOT running!");

  }

    Serial.println("Robojax Digitla Clock");
  Serial.println("using DS1307 and HT16K33");  

    // following line sets the RTC to the date & time this sketch was compiled
    // 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, 3, 3, 20, 0, 0));
  //rtc.adjust(DateTime(2019, 3, 3, 8, 1, 0));
   rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

 //settings for seven sigment display
  seg.begin();
  Wire.setClock(100000);

  seg.displayOn();

  seg.setDigits(4);
  seg.displayTest(1); 
   
  seg.displayOff(); 
  delay(50);
  seg.displayOn();  
  seg.brightness(10);//set brightness from 1-15        
}

void loop () {
  (showLeadingZero)? seg.setDigits(4) : seg.setDigits(3);
  
    DateTime now = rtc.now();
     //printTime();//print time on serial monitor   

  seg.displayTime(now.hour(),now.minute());
  seg.displayColon(1);     
  delay(500);
  seg.displayColon(0);  
  delay(500); 

  (showSecondNoBlink)? showSeconds2() : showSeconds1();  
    
}//loop end

/*
 * 
 * @brief shows seconds on HT16K33 display
 * with blinking
 * @param none
 * @return no return value
 * written Feb 06, 2021 by Ahmad Shamshiri
 * www.robojax.com
 */
void showSeconds1()
{
  int count = secondBlinkCount;
  if(showSecond){
      if(millis() - rememberTime   > secondDisplayEvery)
      {
          while(count>=0)
          {
            DateTime now = rtc.now();       
            count -=1;      
            seg.setDigits(2);    
            seg.displayInt(now.second());     
            delay(500);
            seg.displayOff();  
            delay(500);  
            seg.displayOn();
            rememberTime = millis()  ;  
          }// while end    
      }//if
  }//if showSecond is true
}//showSecond() end

/*
 * 
 * @brief shows seconds on HT16K33 display
 * without blinking. 
 * @param none
 * @return no return value
 * written Feb 06, 2021 by Ahmad Shamshiri
 * www.robojax.com
 */
void showSeconds2()
{
  int count = secondDisplayDuration;

  if(showSecond){
      if(millis() - rememberTime   > secondDisplayEvery)
      {
          while(count>=0)
          {        
            DateTime now = rtc.now();        
            count -=50;      
            seg.setDigits(2);    
            seg.displayInt(now.second());     
            delay(50);
            rememberTime = millis()  ;  
          }// while end    
      }//if
  }//if showSecond is true
}//showSeconds2() end

/*
 * 
 * @brief prints time on serial monitor
 * @param none
 * @return no return value
 * written Feb 06, 2021 by Ahmad Shamshiri
 * www.robojax.com
 */
void printTime()
{
  
    DateTime now = rtc.now();
    
    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    Serial.print(now.day(), DEC);
    Serial.print(" (");
    Serial.print(daysOfTheWeek[now.dayOfTheWeek()]);
    Serial.print(") ");
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();
}//printTime() end

 
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