The DS3231 RTC module Precise Real-Time Clock Module is a low-cost, extremely accurate I²C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input and maintains accurate timekeeping when the main power to the device is interrupted.
 
The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line. The ds3231 Arduino is available in commercial and industrial temperature ranges and is offered in a 16-pin, 300-mil SO package.
 
Features:
Two Time-of-Day Alarms.
Digital Temp Sensor Output.
Register for Aging Trim.
DS 3231 RTC with 2032 Battery Holder.
Highly Accurate RTC Completely Manages All Timekeeping Functions.
Real-Time Clock Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year, with Leap-Year Compensation Valid Up to 2100.
Configurable I2C device Address for AT24C32 using SMD jumpers on PCB (A0, A1, A2).
Programmable Square-Wave Output Signal.
Battery-Backup Input for Continuous Timekeeping.
Low Power Operation Extends Battery-Backup Run Time.