DS1307, DS3231 and DS3232 RTCs basic libraryReally tiny library to basic RTC functionality on Arduino.

Supported features:

SQuare Wave Generator
Fixed output pin for DS1307
RAM for DS1307 and DS3232
temperature sensor for DS3231 and DS3232
Alarms (1 and 2) for DS3231 and DS3232
Power failure check and clear

See uEEPROMLib for EEPROM support, https://github.com/Naguissa/uEEPROMLib

Note: For AtTiny you need TinyWireM library from Adafruit installed (available on library manager).

I2C locked in unknown state

If uC crashes and I2C communication is locked in a unknown state you have a procedure to unlock it. It's not implemented in this library but you can find an explanation and a PIC implementation thanks to @rtek1000 in #42 : https://github.com/Naguissa/uRTCLib/issues/42

See also: https://github.com/Naguissa/uRTCLib; https://www.foroelectro.net/librerias-arduino-ide-f29/rtclib-arduino-libreria-simple-y-eficaz-para-rtc-y-t95.html; naguissa@foroelectro.net; See uEEPROMLib for EEPROM support.

Version: 6.9.2