Manual adjust for RTC clock with Arduino and 7-segment LED display

   For a good clock must use a RTC (real-time clock) like DS1307. For Arduino enthusiasts and hobbylist exists some RTC module with DS1307, but you can made yourself a good RTC module like me.

   Original schematic is from DS1307 datasheet, but I redesigned schematic using freeversion of Eagle PCB Software:

   Note: Battery is CR2032, like in schematic... in boards is a little error

   A full schematic for RTC clock with Arduino is:

   Compared to other schematics that can adjust time (reset clock at 0:00, adjust hours and minutes). Original schematic, design and sketch is from article Using Arduino with a DS1307 Real Time Clock by Lewis Loflin.

   If you want to change time, must push and hold S3 (adjust) switch and display is change on 0:00, then push S1 (hour) or S2 (minute) repeatedly until time is ok, after this realise S3, and time is put in RTC.

   I use a multiplexed 4-digit 7-segment display with common anode same in article named Arduino UNO running 4-digit 7-segment display from http://www.hobbytronics.co.uk/. Is a unusual schematic, but works fine; a usual schematic use resistors for current limit.

   My sketch is:

/*
 4 digit 7 segment display: http://www.sparkfun.com/products/9483
 Datasheet: http://www.sparkfun.com/datasheets/Components/LED/7-Segment/YSD-439AR6B-35.pdf
 7 segments + 4 digits + 1 colon = 12 pins required for full control 
 */
// modified connexion by niq_ro from http://nicuflorica.blogspot.com
// for my Luckylight KW4-563ASA
// dataseet: http://www.tme.eu/ro/Document/dfc2efde2e22005fd28615e298ea2655/KW4-563XSA.pdf

int digit1 = 11; //PWM Display pin 12 (digit1 is common anonds A1 from right side)
int digit2 = 10; //PWM Display pin 9 (digit2 is  common A2)
int digit3 = 9; //PWM Display pin 8 (digit3 is common anods A3)
int digit4 = 6; //PWM Display pin 6 (digit4 is common anods, from left side)

//Pin mapping from Arduino to the ATmega DIP28 if you need it
//http://www.arduino.cc/en/Hacking/PinMapping
int segA = 2; //Display pin 11
int segB = 3; //Display pin 7
int segC = 4; //Display pin 4
int segD = 5; //Display pin 2
int segE = 12; //Display pin 1
int segF = 7; //Display pin 10
int segG = 8; //Display pin 5
int segDP = 13; // Display pin 3

#include <Wire.h>
#include "RTClib.h"
RTC_DS1307 RTC;

// Date and time functions using a DS1307 RTC connected via I2C and Wire lib
// original sketck from http://learn.adafruit.com/ds1307-real-time-clock-breakout-board-kit/
// add part with SQW=1Hz from http://tronixstuff.wordpress.com/2010/10/20/tutorial-arduino-and-the-i2c-bus/
// add part with manual adjust http://www.bristolwatch.com/arduino/arduino_ds1307.htm




byte SW0 = A0;
byte SW1 = A1;
byte SW2 = A2;

// use for hexa in zecimal conversion
int zh, uh, ore;
int zm, um, miniti;

void setup() {
  
 //  Serial.begin(57600);
  Wire.begin();
  RTC.begin();
// RTC.adjust(DateTime(__DATE__, __TIME__));
// if you need set clock... just remove // from line above this

// part code for flashing LED
Wire.beginTransmission(0x68);
Wire.write(0x07); // move pointer to SQW address
// Wire.write(0x00); // turns the SQW pin off
 Wire.write(0x10); // sends 0x10 (hex) 00010000 (binary) to control register - turns on square wave at 1Hz
// Wire.write(0x13); // sends 0x13 (hex) 00010011 (binary) 32kHz

Wire.endTransmission();

  if (! RTC.isrunning()) {
    Serial.println("RTC is NOT running!");
    // following line sets the RTC to the date & time this sketch was compiled
    RTC.adjust(DateTime(__DATE__, __TIME__));
  }
  
  
// dht.begin();

  pinMode(segA, OUTPUT);
  pinMode(segB, OUTPUT);
  pinMode(segC, OUTPUT);
  pinMode(segD, OUTPUT);
  pinMode(segE, OUTPUT);
  pinMode(segF, OUTPUT);
  pinMode(segG, OUTPUT);
  pinMode(segDP, OUTPUT);

  pinMode(digit1, OUTPUT);
  pinMode(digit2, OUTPUT);
  pinMode(digit3, OUTPUT);
  pinMode(digit4, OUTPUT);
  
//  pinMode(13, OUTPUT);

 Serial.begin(9600);
 Serial.println("test for niq_ro");

 pinMode(SW0, INPUT);  // for this use a slide switch
  pinMode(SW1, INPUT);  // N.O. push button switch
  pinMode(SW2, INPUT);  // N.O. push button switch

  digitalWrite(SW0, HIGH); // pull-ups on
  digitalWrite(SW1, HIGH);
  digitalWrite(SW2, HIGH);



}

void loop() {
digitalWrite(segDP, HIGH);
  DateTime now = RTC.now();
  int timp = now.hour()*100+now.minute();
//   int timp = (now.minute(), DEC);
//   displayNumber(12); // this is number to diplay
//   int timp = 1234;
  Serial.print(now.hour(), DEC);
  Serial.print(":");
  Serial.print(now.minute(), DEC);
  Serial.print(" -> ");
  Serial.print(timp);
  Serial.println(" !");

// display parts   
   for(int i = 250 ; i >0  ; i--) {
     if (timp >= 1000) displayNumber01(timp); 
     else displayNumber02(timp); 
   } 

   for(int i = 250 ; i >0  ; i--) {
     if (timp >= 1000) displayNumber03(timp); 
     else displayNumber04(timp); 
   } 

  if (!(digitalRead(SW0))) set_time(); // hold the switch to set time
} 


void set_time()   {
  byte minutes1 = 0;
  byte hours1 = 0;
  byte minutes = 0;
  byte hours = 0;

  while (!digitalRead(SW0))  // set time switch must be released to exit
  {
    minutes1=minutes;
    hours1=hours;
    
     
    while (!digitalRead(SW1)) // set minutes
    { 
     minutes++;  
   // converting hexa in zecimal:
    zh = hours / 16;
    uh = hours - 16 * zh ;
    ore = 10 * zh + uh; 
    zm = minutes / 16;
    um = minutes - 16 * zm ;
    miniti = 10 * zm + um; 
    
     for(int i = 20 ; i >0  ; i--) {
     displayNumber01(ore*100+miniti); 
     }

      
      if ((minutes & 0x0f) > 9) minutes = minutes + 6;
      if (minutes > 0x59) minutes = 0;
      Serial.print("Minutes = ");
      if (minutes >= 9) Serial.print("0");
      Serial.println(minutes, HEX);
    delay(150);    
    }

    while (!digitalRead(SW2)) // set hours
    { 
     hours++;          
     
   // converting hexa in zecimal:
    zh = hours / 16;
    uh = hours - 16 * zh ;
    ore = 10 * zh + uh; 
    zm = minutes / 16;
    um = minutes - 16 * zm ;
    miniti = 10 * zm + um; 
    
     for(int i = 20 ; i >0  ; i--) {
     displayNumber01(ore*100+miniti); 
     }
   
      
      if ((hours & 0x0f) > 9) hours =  hours + 6;
      if (hours > 0x23) hours = 0;
      Serial.print("Hours = ");
      if (hours <= 9) Serial.print("0");
      Serial.println(hours, HEX);
    delay(150);
    }

    Wire.beginTransmission(0x68); // activate DS1307
    Wire.write(0); // where to begin
    Wire.write(0x00);          //seconds
    Wire.write(minutes);          //minutes
    Wire.write(0x80 | hours);    //hours (24hr time)
    Wire.write(0x06);  // Day 01-07
    Wire.write(0x01);  // Date 0-31
    Wire.write(0x05);  // month 0-12
    Wire.write(0x09);  // Year 00-99
    Wire.write(0x10); // Control 0x10 produces a 1 HZ square wave on pin 7. 
    Wire.endTransmission();
  
    // converting hexa in zecimal:
    zh = hours / 16;
    uh = hours - 16 * zh ;
    ore = 10 * zh + uh; 
    zm = minutes / 16;
    um = minutes - 16 * zm ;
    miniti = 10 * zm + um; 
    
     for(int i = 20 ; i >0  ; i--) {
     displayNumber01(ore*100+miniti); 
     }
 //  delay(150);
    
  }
  
}



void displayNumber01(int toDisplay) {
#define DISPLAY_BRIGHTNESS  500

#define DIGIT_ON  HIGH
#define DIGIT_OFF  LOW

  for(int digit = 4 ; digit > 0 ; digit--) {

    //Turn on a digit for a short amount of time
    switch(digit) {
    case 1:
     digitalWrite(digit1, DIGIT_ON);
     digitalWrite(segDP, HIGH);
      break;
   case 2:
      digitalWrite(digit2, DIGIT_ON);
      digitalWrite(segDP, LOW);
      break;
    case 3:
      digitalWrite(digit3, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 4:
      digitalWrite(digit4, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    }
    lightNumber(toDisplay % 10);
    toDisplay /= 10;
    delayMicroseconds(DISPLAY_BRIGHTNESS); 

     //Turn off all segments
    lightNumber(10); 

    //Turn off all digits
    digitalWrite(digit1, DIGIT_OFF);
    digitalWrite(digit2, DIGIT_OFF);
    digitalWrite(digit3, DIGIT_OFF);
    digitalWrite(digit4, DIGIT_OFF);
}
} 

void displayNumber02(int toDisplay) {
#define DISPLAY_BRIGHTNESS  500

#define DIGIT_ON  HIGH
#define DIGIT_OFF  LOW

  for(int digit = 4 ; digit > 0 ; digit--) {

    //Turn on a digit for a short amount of time
    switch(digit) {
    case 1:
     lightNumber(10); 
     digitalWrite(segDP, HIGH);
     break;
   case 2:
      digitalWrite(digit2, DIGIT_ON);
      digitalWrite(segDP, LOW);
      break;
    case 3:
      digitalWrite(digit3, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 4:
      digitalWrite(digit4, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    }
    lightNumber(toDisplay % 10);
    toDisplay /= 10;
    delayMicroseconds(DISPLAY_BRIGHTNESS); 

     //Turn off all segments
    lightNumber(10); 

    //Turn off all digits
    digitalWrite(digit1, DIGIT_OFF);
    digitalWrite(digit2, DIGIT_OFF);
    digitalWrite(digit3, DIGIT_OFF);
    digitalWrite(digit4, DIGIT_OFF);
}
} 

void displayNumber03(int toDisplay) {
#define DISPLAY_BRIGHTNESS  500

#define DIGIT_ON  HIGH
#define DIGIT_OFF  LOW

  for(int digit = 4 ; digit > 0 ; digit--) {

    //Turn on a digit for a short amount of time
    switch(digit) {
    case 1:
     digitalWrite(digit1, DIGIT_ON);
     digitalWrite(segDP, HIGH);
      break;
   case 2:
      digitalWrite(digit2, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 3:
      digitalWrite(digit3, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 4:
      digitalWrite(digit4, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    }
    lightNumber(toDisplay % 10);
    toDisplay /= 10;
    delayMicroseconds(DISPLAY_BRIGHTNESS); 

     //Turn off all segments
    lightNumber(10); 

    //Turn off all digits
    digitalWrite(digit1, DIGIT_OFF);
    digitalWrite(digit2, DIGIT_OFF);
    digitalWrite(digit3, DIGIT_OFF);
    digitalWrite(digit4, DIGIT_OFF);
}
} 

void displayNumber04(int toDisplay) {
#define DISPLAY_BRIGHTNESS  500

#define DIGIT_ON  HIGH
#define DIGIT_OFF  LOW

  for(int digit = 4 ; digit > 0 ; digit--) {

    //Turn on a digit for a short amount of time
    switch(digit) {
    case 1:
     lightNumber(10); 
     digitalWrite(segDP, HIGH);
     break;
   case 2:
      digitalWrite(digit2, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 3:
      digitalWrite(digit3, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    case 4:
      digitalWrite(digit4, DIGIT_ON);
      digitalWrite(segDP, HIGH);
      break;
    }
    lightNumber(toDisplay % 10);
    toDisplay /= 10;
    delayMicroseconds(DISPLAY_BRIGHTNESS); 

     //Turn off all segments
    lightNumber(10); 

    //Turn off all digits
    digitalWrite(digit1, DIGIT_OFF);
    digitalWrite(digit2, DIGIT_OFF);
    digitalWrite(digit3, DIGIT_OFF);
    digitalWrite(digit4, DIGIT_OFF);
}
} 


//Given a number, turns on those segments
//If number == 10, then turn off number
void lightNumber(int numberToDisplay) {

#define SEGMENT_ON  LOW
#define SEGMENT_OFF HIGH

  switch (numberToDisplay){

  case 0:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 1:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 2:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_OFF);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 3:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 4:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 5:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 6:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 7:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 8:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 9:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  // all segment are ON
  case 10:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_OFF);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;
  
  }
}

   I made a litle movie named manual adjust for RTC clock with Arduino and 7-segment LED display

Note: Original article in roumanian language is Afisaje LED cu 7 segmente si.. Arduino (IV)!!!

11.10.2016
   I correct sketch for display 10:00 case..

07.02.2017

    Now, I pun on my Github channel sketch for cathode comon display, see github.com/tehniq3/multiplexedclock