The DS3231 is an extremely accurate I2C real-time clock with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The DS3231 function with a VCC ranging from 2.3V to 5.5V. In comparison to the DS1307, the DS3231 has an integrated crystal, temperature sensor, 2 programmable time-of-day alarms, a 32.768 kHz output pin to ensure higher accuracy.

Note:The CR2032coin cell battery is not included.