A fork of Jeelab's fantastic RTC library
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README.md Update README.md Jan 13, 2016
RTClib.cpp Merge 'TimeStamp' by github/AxelTB Jan 8, 2016
keywords.txt added Keyword Timespan Jan 8, 2016


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, 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 arduino_sketch_folder/libraries/ folder. You may need to create the libraries subfolder if its your first library. Restart the IDE.

Basic functions (see libraries/examples of how to use):

  • .begin
  • .adjust
  • .isrunning
  • .now

DS1307 specific functions:

  • .readnvram
  • .writenvram
  • .readSqwPinMode
  • .writeSqwPinMode

PCF8523 specific functions:

  • .writeSqwPinMode

DS3231 specific functions:

  • .getTemperature
  • .getA1Time
  • .setA1Time
  • .setAlarm1Simple
  • .turnOnAlarm
  • .turnOffAlarm
  • .checkAlarmEnabled
  • .checkIfAlarm

Millis (software RTC) specific functions:

  • .checkRollover

DS3231 functionality tested on Arduino Pro Mini (Jan 8, 2016 - MrAlvin)

For other compatibility details see https://github.com/adafruit/RTClib


  • debug Alarm2
  • make DS3231 SQW functon calls similar to DS1307 function calls