DS3231 RTC Clock Module

DS3231 is an extremely accurate real-time clock (RTC) that keeps track of time even when the external power supply is disconnected. It provides two configurable alarm clock and a calendar that can be set to a square wave output. Address and data are transferred serially through an I2C bidirectional bus. You can use it to create a clock, alarm system and more.
The module also has a precision temperature-compensated voltage reference and comparator circuit, which monitors the status of VCC to detect power failures, provide a reset output, and if necessary, automatically switch to the backup power supply.