This DS3231 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: disconnect the main power supply and it maintains accurate timekeeping.
- Operating voltage :3.3 - 5 .5 V
- The default I2C address is 0x57.
- Use a LIR2032 coin cell battery to keep time even when your project is turned off.