There are applications in which we need the record or time count to be stable and / or accurate, and many times our microcontroller when carrying out several tasks does not have the ability to keep the time count efficiently, that is when they take care this type of circuit called real time clock (RTC for Real time clock).
They exist of different qualities and precisions, we recommend this one, since it is more exact than the DS1307 and that the DS1302 although it is controlled the same as the DS1307 by means of I2C.
It occupies a backup battery of the type CR2032 (not included)
Includes an AT24C32 EEPROM memory
DS3231 minimum circuit (RTC) and EEPROM memory
Works from 3.3 to 5.5V
High precision RTC
Alarms can be programmed
Has square wave output programmable at different frequencies
Measures hours, minutes, seconds, days, months, years, with programming valid until the year 2100
Communicates via I2C port
Includes a 24C32 EEPROM memory
Includes backup battery socket (CR2032, not included) so that the RTC continues to operate even when the main circuit is disconnected
It has a basic 4-pin connector and advanced 6-pin connector