adafruit/RTClib

This is a fork of JeeLab’s fantastic real time clock library for Arduino.

For details on using this library with an RTC module like the DS1307, PCF8523, or DS3231,
see the guide at: https://learn.adafruit.com/ds1307-real-time-clock-breakout-board-kit/overview

To download. click the DOWNLOADS button to the right, and rename the uncompressed folder RTClib.

Place the RTClib folder in your arduinosketchfolder/libraries/ folder.
You may need to create the libraries subfolder if its your first library. Restart the IDE.

Please note that dayOfTheWeek() ranges from 0 to 6 inclusive with 0 being ‘Sunday’

Compatibility

• ATmega328 @ 16MHz : Arduino UNO, Adafruit Pro Trinket 5V, Adafruit Metro 328, Adafruit Metro Mini
• ATmega328 @ 12MHz : Adafruit Pro Trinket 3V
• ATmega32u4 @ 16MHz : Arduino Leonardo, Arduino Micro, Arduino Yun, Teensy 2.0
• ATmega32u4 @ 8MHz : Adafruit Flora, Bluefruit Micro
• ESP8266 : Adafruit Huzzah
• ATmega2560 @ 16MHz : Arduino Mega
• ATSAM3X8E : Arduino Due
• ATSAM21D : Arduino Zero, M0 Pro
• ATtiny85 @ 16MHz : Adafruit Trinket 5V
• ATtiny85 @ 8MHz : Adafruit Gemma, Arduino Gemma, Adafruit Trinket 3V

~https://github.com/adafruit/RTClib/

Makuna/Rtc

Arduino Real Time Clock library.
An RTC library with deep device support.
Now supports esp8266. Now supports SoftwareWire library.

Overview

This is an Arduino Library that has deep support for Real Time Clock modules.

Please see the FAQ for common questions and answers.

Supported RTC chip sets

DS1307
Full support including squarewave output pin and memory access

DS3231
Full support including squarewave output pin and alarms.

Examples

There are several examples that will help you get started. They range from simple to complex and are always a good reference.

Connecting the Devices

The RTC devices expose two digital wires labeled SDA and SCL. These need to be connected to the wires exposed by your Arduino board labeled the same way. This varies from board to board so you will need to consult the Arduino reference documents for which pins are the SDA and SCL.
For ESP8266, these default to SDA = GPIO04 and SCL = GPIO05.
The RTC devices also require power. Make sure that VCC is connected to the proper voltage that your device requires. DS1307 requires 5v while the DS3231 can use either 3.3v or 5v. The GND must be connected to the Arduino GND even if you are not powering the RTC from the Arduino voltage pins.

RtcDateTime object 
This object will be used to get and set the date and time. It supports being constructed with various time formats from strings to standard Epoch time formats. It also supports access to individual date and time value for year, month, day, hour, minute, and seconds.

RtcTemperature object 
This object will be used to get the temperature from the RTC module if it supports it.

RtcDS1307 object 
This object will expose the features of the DS1307 RTC chip including access to the onboard memory.

RtcDS3231 object
This object will expose the features of the DS3231 RTC chip including access to the two alarm features.

adafruit: datecalc.ino

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using programming port to program the Zero!
#define Serial SerialUSB
#endif

void showDate(const char* txt, const DateTime& dt) {
Serial.print(txt);
Serial.print(‘ ‘);
Serial.print(dt.year(), DEC);
Serial.print(‘/’);
Serial.print(dt.month(), DEC);
Serial.print(‘/’);
Serial.print(dt.day(), DEC);
Serial.print(‘ ‘);
Serial.print(dt.hour(), DEC);
Serial.print(‘:’);
Serial.print(dt.minute(), DEC);
Serial.print(‘:’);
Serial.print(dt.second(), DEC);

Serial.print(" = ");
Serial.print(dt.unixtime());
Serial.print("s / ");
Serial.print(dt.unixtime() / 86400L);
Serial.print("d since 1970");

Serial.println();
}

void showTimeSpan(const char* txt, const TimeSpan& ts) {
Serial.print(txt);
Serial.print(" ");
Serial.print(ts.days(), DEC);
Serial.print(" days ");
Serial.print(ts.hours(), DEC);
Serial.print(" hours ");
Serial.print(ts.minutes(), DEC);
Serial.print(" minutes ");
Serial.print(ts.seconds(), DEC);
Serial.print(" seconds (");
Serial.print(ts.totalseconds(), DEC);
Serial.print(" total seconds)");
Serial.println();
}

void setup () {

#ifndef ESP8266
while (!Serial); // for Leonardo/Micro/Zero
#endif
// Serial.begin(57600);
Serial.begin(9600);

DateTime dt0 (0, 1, 1, 0, 0, 0);
showDate("dt0", dt0);

DateTime dt1 (1, 1, 1, 0, 0, 0);
showDate("dt1", dt1);

DateTime dt2 (2009, 1, 1, 0, 0, 0);
showDate("dt2", dt2);

DateTime dt3 (2009, 1, 2, 0, 0, 0);
showDate("dt3", dt3);

DateTime dt4 (2009, 1, 27, 0, 0, 0);
showDate("dt4", dt4);

DateTime dt5 (2009, 2, 27, 0, 0, 0);
showDate("dt5", dt5);

DateTime dt6 (2017, 7, 20, 9, 8, 7);
showDate("dt6", dt6);

DateTime dt7 (dt6.unixtime() + 3600); // One hour later.
showDate("dt7", dt7);

DateTime dt75 = dt6 + TimeSpan(0, 1, 0, 0); // One hour later with TimeSpan addition.
showDate("dt7.5", dt75);

DateTime dt8 (dt6.unixtime() + 86400L); // One day later.
showDate("dt8", dt8);

DateTime dt85 = dt6 + TimeSpan(1, 0, 0, 0); // One day later with TimeSpan addition.
showDate("dt8.5", dt85);

DateTime dt9 (dt6.unixtime() + 7 * 86400L); // One week later.
showDate("dt9", dt9);

DateTime dt95 = dt6 + TimeSpan(7, 0, 0, 0); // One week later with TimeSpan addition.
showDate("dt9.5", dt95);

DateTime dt10 = dt6 + TimeSpan(0, 0, 42, 42); // Fourty two minutes and fourty two seconds later.
showDate("dt10", dt10);

DateTime dt11 = dt6 – TimeSpan(7, 0, 0, 0); // One week ago.
showDate("dt11", dt11);

TimeSpan ts1 = dt6 – dt5;
showTimeSpan("dt6-dt5", ts1);

TimeSpan ts2 = dt10 – dt6;
showTimeSpan("dt10-dt6", ts2);
}

void loop () {
}

adafruit: ds1307SqwPin.ino

// NOTE:
// You must connect a pull up resistor (~10kohm) from the SQW pin up to VCC. Without
// this pull up the wave output will not work!

#include <Wire.h>
#include "RTClib.h"

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using programming port to program the Zero!
#define Serial SerialUSB
#endif

RTC_DS1307 rtc;

int mode_index = 0;

Ds1307SqwPinMode modes[] = {OFF, ON, SquareWave1HZ, SquareWave4kHz, SquareWave8kHz, SquareWave32kHz};

void print_mode() {
Ds1307SqwPinMode mode = rtc.readSqwPinMode();

Serial.print("Sqw Pin Mode: ");
switch(mode) {
case OFF: Serial.println("OFF"); break;
case ON: Serial.println("ON"); break;
case SquareWave1HZ: Serial.println("1Hz"); break;
case SquareWave4kHz: Serial.println("4.096kHz"); break;
case SquareWave8kHz: Serial.println("8.192kHz"); break;
case SquareWave32kHz: Serial.println("32.768kHz"); break;
default: Serial.println("UNKNOWN"); break;
}
}

void setup () {

#ifndef ESP8266
while (!Serial); // for Leonardo/Micro/Zero
#endif

// Serial.begin(57600);
Serial.begin(9600);

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

print_mode();
}

void loop () {
rtc.writeSqwPinMode(modes[mode_index++]);
print_mode();

if (mode_index > 5) {
mode_index = 0;
}

delay(5000);
}
[/code]

adafruit: ds1307nvram.ino

#include <Wire.h>
#include "RTClib.h"

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using programming port to program the Zero!
#define Serial SerialUSB
#endif

RTC_DS1307 rtc;

void printnvram(uint8_t address) {
Serial.print("Address 0x");
Serial.print(address, HEX);
Serial.print(" = 0x");
Serial.println(rtc.readnvram(address), HEX);
}

void setup () {

#ifndef ESP8266
while (!Serial); // for Leonardo/Micro/Zero
#endif
// Serial.begin(57600);
Serial.begin(9600);

rtc.begin();

// Print old RAM contents on startup.
Serial.println("Current NVRAM values:");
for (int i = 0; i < 6; ++i) {
printnvram(i);
}

// Write some bytes to non-volatile RAM storage.
// NOTE: You can only read and write from addresses 0 to 55 (i.e. 56 byte values).
Serial.println("Writing NVRAM values.");
// Example writing one byte at a time:
rtc.writenvram(0, 0xFE);
rtc.writenvram(1, 0xED);
// Example writing multiple bytes:
uint8_t writeData[4] = { 0xBE, 0xEF, 0x01, 0x02 };
rtc.writenvram(2, writeData, 4);

// Read bytes from non-volatile RAM storage.
Serial.println("Reading NVRAM values:");
// Example reading one byte at a time.
Serial.println(rtc.readnvram(0), HEX);
Serial.println(rtc.readnvram(1), HEX);
// Example reading multiple bytes:
uint8_t readData[4] = {0};
rtc.readnvram(readData, 4, 2);
Serial.println(readData[0], HEX);
Serial.println(readData[1], HEX);
Serial.println(readData[2], HEX);
Serial.println(readData[3], HEX);

}

void loop () {
// Do nothing in the loop.
}
[/code]

adafruit: softrtc.ino

#include <Arduino.h>
#include <Wire.h> // this #include still required because the RTClib depends on it
#include "RTClib.h"

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using programming port to program the Zero!
#define Serial SerialUSB
#endif

RTC_Millis rtc;

void setup () {
// Serial.begin(57600);
Serial.begin(9600);

// following line sets the RTC to the date &amp; time this sketch was compiled
rtc.begin(DateTime(F(__DATE__), F(__TIME__)));
// This line sets the RTC with an explicit date &amp; time, for example to set
// January 21, 2014 at 3am you would call:
// rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
}

void loop () {
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(now.hour(), DEC);
Serial.print(‘:’);
Serial.print(now.minute(), DEC);
Serial.print(‘:’);
Serial.print(now.second(), DEC);
Serial.println();

Serial.print(" seconds since 1970: ");
Serial.println(now.unixtime());

// calculate a date which is 7 days and 30 seconds into the future
DateTime future (now.unixtime() + 7 * 86400L + 30);

Serial.print(" now + 7d + 30s: ");
Serial.print(future.year(), DEC);
Serial.print(‘/’);
Serial.print(future.month(), DEC);
Serial.print(‘/’);
Serial.print(future.day(), DEC);
Serial.print(‘ ‘);
Serial.print(future.hour(), DEC);
Serial.print(‘:’);
Serial.print(future.minute(), DEC);
Serial.print(‘:’);
Serial.print(future.second(), DEC);
Serial.println();

Serial.println();
delay(3000);
}
[/code]

Makuna: DS1307_Simple.ino

#if defined(ESP8266)
#include <pgmspace.h>
#else
#include <avr/pgmspace.h>
#endif

/* for software wire use below
#include <SoftwareWire.h> // must be included here so that Arduino library object file references work
#include <RtcDS1307.h>

SoftwareWire myWire(SDA, SCL);
RtcDS1307<SoftwareWire> Rtc(myWire);
for software wire use above */

/* for normal hardware wire use below */
#include <Wire.h> // must be included here so that Arduino library object file references work
#include <RtcDS1307.h>
RtcDS1307<TwoWire> Rtc(Wire);
/* for normal hardware wire use above */

void setup ()
{
// Serial.begin(57600);
Serial.begin(9600);

Serial.print("compiled: ");
Serial.print(__DATE__);
Serial.println(__TIME__);

//——–RTC SETUP ————
// if you are using ESP-01 then uncomment the line below to reset the pins to
// the available pins for SDA, SCL
// Wire.begin(0, 2); // due to limited pins, use pin 0 and 2 for SDA, SCL

Rtc.Begin();

RtcDateTime compiled = RtcDateTime(__DATE__, __TIME__);
printDateTime(compiled);
Serial.println();

if (!Rtc.IsDateTimeValid())
{
// Common Cuases:
// 1) first time you ran and the device wasn’t running yet
// 2) the battery on the device is low or even missing

Serial.println("RTC lost confidence in the DateTime!");

// following line sets the RTC to the date &amp; time this sketch was compiled
// it will also reset the valid flag internally unless the Rtc device is
// having an issue

Rtc.SetDateTime(compiled);
}

if (!Rtc.GetIsRunning())
{
Serial.println("RTC was not actively running, starting now");
Rtc.SetIsRunning(true);
}

RtcDateTime now = Rtc.GetDateTime();
if (now < compiled)
{
Serial.println("RTC is older than compile time! (Updating DateTime)");
Rtc.SetDateTime(compiled);
}
else if (now > compiled)
{
Serial.println("RTC is newer than compile time. (this is expected)");
}
else if (now == compiled)
{
Serial.println("RTC is the same as compile time! (not expected but all is fine)");
}

// never assume the Rtc was last configured by you, so
// just clear them to your needed state
Rtc.SetSquareWavePin(DS1307SquareWaveOut_Low);
}

void loop ()
{
if (!Rtc.IsDateTimeValid())
{
// Common Cuases:
// 1) the battery on the device is low or even missing and the power line was disconnected
Serial.println("RTC lost confidence in the DateTime!");
}

RtcDateTime now = Rtc.GetDateTime();

printDateTime(now);
Serial.println();

delay(10000); // ten seconds
}

#define countof(a) (sizeof(a) / sizeof(a[0]))

void printDateTime(const RtcDateTime&amp; dt)
{
char datestring[20];

snprintf_P(datestring,
countof(datestring),
PSTR("%02u/%02u/%04u %02u:%02u:%02u"),
dt.Month(),
dt.Day(),
dt.Year(),
dt.Hour(),
dt.Minute(),
dt.Second() );
Serial.print(datestring);
}

Makuna: DS1307_Memory.ino

// CONNECTIONS:
// DS1307 SDA --> SDA
// DS1307 SCL --> SCL
// DS1307 VCC --> 5v
// DS1307 GND --> GND

#define countof(a) (sizeof(a) / sizeof(a[0]))

#if defined(ESP8266)
#include <pgmspace.h>
#else
#include <avr/pgmspace.h>
#endif

/* for software wire use below
#include <SoftwareWire.h> // must be included here so that Arduino library object file references work
#include <RtcDS1307.h>

SoftwareWire myWire(SDA, SCL);
RtcDS1307<SoftwareWire> Rtc(myWire);
for software wire use above */

/* for normal hardware wire use below */
#include <Wire.h> // must be included here so that Arduino library object file references work
#include <RtcDS1307.h>
RtcDS1307<TwoWire> Rtc(Wire);
/* for normal hardware wire use above */

const char data[] = “what time is it”;

void setup ()
{
// Serial.begin(57600);
Serial.begin(9600);

Serial.print(“compiled: “);
Serial.print(__DATE__);
Serial.println(__TIME__);

//——–RTC SETUP ————
// if you are using ESP-01 then uncomment the line below to reset the pins to
// the available pins for SDA, SCL
// Wire.begin(0, 2); // due to limited pins, use pin 0 and 2 for SDA, SCL

Rtc.Begin();

RtcDateTime compiled = RtcDateTime(__DATE__, __TIME__);
printDateTime(compiled);
Serial.println();

if (!Rtc.IsDateTimeValid())
{
Serial.println(“RTC lost confidence in the DateTime!”);
Rtc.SetDateTime(compiled);
}

if (!Rtc.GetIsRunning())
{
Serial.println(“RTC was not actively running, starting now”);
Rtc.SetIsRunning(true);
}

RtcDateTime now = Rtc.GetDateTime();
if (now < compiled)
{
Serial.println(“RTC is older than compile time! (Updating DateTime)”);
Rtc.SetDateTime(compiled);
}

// never assume the Rtc was last configured by you, so
// just clear them to your needed state
Rtc.SetSquareWavePin(DS1307SquareWaveOut_Low);

/* comment out on a second run to see that the info is stored long term */
// Store something in memory on the RTC
Rtc.SetMemory(0, 13);
uint8_t written = Rtc.SetMemory(13, (const uint8_t*)data, sizeof(data) – 1); // remove the null terminator strings add
Rtc.SetMemory(1, written);
/* end of comment out section */
}

void loop ()
{
if (!Rtc.IsDateTimeValid())
{
// Common Cuases:
// 1) the battery on the device is low or even missing and the power line was disconnected
Serial.println(“RTC lost confidence in the DateTime!”);
}

RtcDateTime now = Rtc.GetDateTime();

printDateTime(now);
Serial.println();

delay(5000);

// read data

// get the offset we stored our data from address zero
uint8_t address = Rtc.GetMemory(0);
if (address != 13)
{
Serial.println(“address didn’t match”);
}
else
{
// get the size of the data from address 1
uint8_t count = Rtc.GetMemory(1);
uint8_t buff[20];

// get our data from the address with the given size
uint8_t gotten = Rtc.GetMemory(address, buff, count);

if (gotten != count ||
count != sizeof(data) – 1) // remove the extra null terminator strings add
{
Serial.print(“something didn’t match, count = “);
Serial.print(count, DEC);
Serial.print(“, gotten = “);
Serial.print(gotten, DEC);
Serial.println();
}
Serial.print(“data read (“);
Serial.print(gotten);
Serial.print(“) = \””);
while (gotten > 0)
{
Serial.print((char)buff[count – gotten]);
gotten–;
}
Serial.println(“\””);
}

delay(5000);
}

void printDateTime(const RtcDateTime& dt)
{
char datestring[20];

snprintf_P(datestring,
countof(datestring),
PSTR(“%02u/%02u/%04u %02u:%02u:%02u”),
dt.Month(),
dt.Day(),
dt.Year(),
dt.Hour(),
dt.Minute(),
dt.Second() );
Serial.print(datestring);
}

Uji kode elcrow dengan Adafruit RTClib.

void setup ()
{
Serial.begin(9600);
Wire.begin();
RTC.begin();
if (! RTC.isrunning())
{
Serial.println("RTC is NOT running!");
// following line sets the RTC to the date &amp; time this sketch was compiled
RTC.adjust(DateTime(__DATE__, __TIME__));
}
}
void loop ()
{
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(now.hour(), DEC);
Serial.print(‘:’);
Serial.print(now.minute(), DEC);
Serial.print(‘:’);
Serial.print(now.second(), DEC);
Serial.println();
Serial.println("Uji RTC");
Serial.println(" ");

delay(1000);
}
[/code]

http://www.theorycircuit.com/rtc-ds-1307-arduino/

void setup(){
Wire.begin();
Serial.begin(9600);
setDateTime(); //MUST CONFIGURE IN FUNCTION
}

void loop(){
printDate();
delay(1000);
}

void setDateTime(){

byte second = 45; //0-59
byte minute = 40; //0-59
byte hour = 0; //0-23
byte weekDay = 2; //1-7
byte monthDay = 1; //1-31
byte month = 3; //1-12
byte year = 11; //0-99

Wire.beginTransmission(DS1307_ADDRESS);
Wire.write(zero);

Wire.write(decToBcd(second));
Wire.write(decToBcd(minute));
Wire.write(decToBcd(hour));
Wire.write(decToBcd(weekDay));
Wire.write(decToBcd(monthDay));
Wire.write(decToBcd(month));
Wire.write(decToBcd(year));

Wire.write(zero); //start

Wire.endTransmission();

}

byte decToBcd(byte val){
// Convert normal decimal numbers to binary coded decimal
return ( (val/10*16) + (val%10) );
}

byte bcdToDec(byte val) {
// Convert binary coded decimal to normal decimal numbers
return ( (val/16*10) + (val%16) );
}

void printDate(){

// Reset the register pointer
Wire.beginTransmission(DS1307_ADDRESS);
Wire.write(zero);
Wire.endTransmission();

Wire.requestFrom(DS1307_ADDRESS, 7);

int second = bcdToDec(Wire.read());
int minute = bcdToDec(Wire.read());
int hour = bcdToDec(Wire.read() &amp; 0b111111); //24 hour time
int weekDay = bcdToDec(Wire.read()); //0-6 -> sunday – Saturday
int monthDay = bcdToDec(Wire.read());
int month = bcdToDec(Wire.read());
int year = bcdToDec(Wire.read());

//print the date EG 3/1/11 23:59:59
Serial.print(month);
Serial.print("/");
Serial.print(monthDay);
Serial.print("/");
Serial.print(year);
Serial.print(" ");
Serial.print(hour);
Serial.print(":");
Serial.print(minute);
Serial.print(":");
Serial.println(second);

}[/code]