The library is DS3232RTC.h .
Regarding the wiring, apart of +Vcc and GND (that are connected to +5V and GND),
PIN SDA is connected to Arduino PIN A4 and SCL is connected to A5.
This is the code. Thanks a lot.
// Arduino DS3232RTC Library
// GitHub - JChristensen/DS3232RTC: Arduino Library for Maxim Integrated DS3232 and DS3231 Real-Time Clocks
// Copyright (C) 2018 by Jack Christensen and licensed under
// GNU GPL v3.0, The GNU General Public License v3.0 - GNU Project - Free Software Foundation
//
// Example sketch to display the date and time from a DS3231
// or DS3232 RTC every second. Display the temperature once per
// minute. (The DS3231 does a temperature conversion once every
// 64 seconds. This is also the default for the DS3232.)
//
// Set the date and time by entering the following on the Arduino
// serial monitor:
// year,month,day,hour,minute,second,
//
// Where
// year can be two or four digits,
// month is 1-12,
// day is 1-31,
// hour is 0-23, and
// minute and second are 0-59.
//
// Entering the final comma delimiter (after "second") will avoid a
// one-second timeout and will allow the RTC to be set more accurately.
//
// No validity checking is done, invalid values or incomplete syntax
// in the input will result in an incorrect RTC setting.
//
// Jack Christensen 08Aug2013
#include <DS3232RTC.h> // GitHub - JChristensen/DS3232RTC: Arduino Library for Maxim Integrated DS3232 and DS3231 Real-Time Clocks
#include <Streaming.h> // Streaming | Arduiniana
void setup()
{
Serial.begin(9600);
// setSyncProvider() causes the Time library to synchronize with the
// external RTC by calling RTC.get() every five minutes by default.
setSyncProvider(RTC.get);
Serial << F("RTC Sync");
if (timeStatus() != timeSet) Serial << F(" FAIL!");
Serial << endl;
}
void loop()
{
static time_t tLast;
time_t t;
tmElements_t tm;
// check for input to set the RTC, minimum length is 12, i.e. yy,m,d,h,m,s
if (Serial.available() >= 12) {
// note that the tmElements_t Year member is an offset from 1970,
// but the RTC wants the last two digits of the calendar year.
// use the convenience macros from the Time Library to do the conversions.
int y = Serial.parseInt();
if (y >= 100 && y < 1000)
Serial << F("Error: Year must be two digits or four digits!") << endl;
else {
if (y >= 1000)
tm.Year = CalendarYrToTm(y);
else // (y < 100)
tm.Year = y2kYearToTm(y);
tm.Month = Serial.parseInt();
tm.Day = Serial.parseInt();
tm.Hour = Serial.parseInt();
tm.Minute = Serial.parseInt();
tm.Second = Serial.parseInt();
t = makeTime(tm);
RTC.set(t); // use the time_t value to ensure correct weekday is set
setTime(t);
Serial << F("RTC set to: ");
printDateTime(t);
Serial << endl;
// dump any extraneous input
while (Serial.available() > 0) Serial.read();
}
}
t = now();
if (t != tLast) {
tLast = t;
printDateTime(t);
if (second(t) == 0) {
float c = RTC.temperature() / 4.;
float f = c * 9. / 5. + 32.;
Serial << F(" ") << c << F(" C ") << f << F(" F");
}
Serial << endl;
}
}
// print date and time to Serial
void printDateTime(time_t t)
{
printDate(t);
Serial << ' ';
printTime(t);
}
// print time to Serial
void printTime(time_t t)
{
printI00(hour(t), ':');
printI00(minute(t), ':');
printI00(second(t), ' ');
}
// print date to Serial
void printDate(time_t t)
{
printI00(day(t), 0);
Serial << monthShortStr(month(t)) << _DEC(year(t));
}
// Print an integer in "00" format (with leading zero),
// followed by a delimiter character to Serial.
// Input value assumed to be between 0 and 99.
void printI00(int val, char delim)
{
if (val < 10) Serial << '0';
Serial << _DEC(val);
if (delim > 0) Serial << delim;
return;
}