Arduino: RTC DS3231

Library

cd ~/Arduino/libraries
mkdir DS3231
wget http://domoticx.phoenixinteractive.nl/arduino/libraries/ds13xx_ds32xx/DS3231%20v1.01.7z
wget http://145.130.102.57/domoticx/arduino/libraries/ds13xx_ds32xx/DS3231%20v1.01.7z
mv DS3231* DS3231
cd DS3231
7z x DS3231\ v1.01.7z 

Source

// DS3231_Serial_Easy (C)2014 Henning Karlsen
// web: http://electronics.henningkarlsen.com/
//
// A quick demo of how to use my DS3231-library to 
// quickly send time and date information over a serial link
//
// To use the hardware I2C (TWI) interface of the Arduino you must connect
// the pins as follows:
//
// Arduino Uno/2009:
// ----------------------
// DS3231:  SDA pin   -> Arduino Analog 4 or the dedicated SDA pin
//          SCL pin   -> Arduino Analog 5 or the dedicated SCL pin
//          VCC pin   -> Arduino 5V
//          GND pin   -> Arduino GND

#include <DS3231.h>
 
// Init the DS3231 using the hardware interface
DS3231  rtc(SDA, SCL);

Time waktu;
 
void setup() {
  // Set the clock to run-mode, and disable the write protection
  rtc.halt(false);
  // rtc.writeProtect(false);
  rtc.writeProtect(true);
  
  // Setup Serial connection
  Serial.begin(9600);
 
  // The following lines can be commented out to use the values already stored in the DS1302
  // rtc.setDOW(MONDAY);        // Set Day-of-Week to MONDAY
  // rtc.setTime(13, 0, 0);     // Set the time to 12:00:00 (24hr format)
  // rtc.setDate(29, 2, 2016);   // Set the date to Feb 2, 2016
}

void loop() {
  waktu = rtc.getTime();
  int dataJam = waktu.hour;     
  int dataMenit = waktu.min;
  int dataDetik = waktu.sec;
  
  // Send Day-of-Week
  Serial.print(rtc.getDOWStr());
  Serial.print(" ");
  
  // Send date
  Serial.print(rtc.getDateStr());
  Serial.print(" -- ");
 
  // Send time
  Serial.println(rtc.getTimeStr());
 
  // Wait one second before repeating :)
  delay (1000);
}