DS3231 high precision clock

The DS3231 is a low cost, high precision I2C real time clock (RTC) with integrated temperature compensated crystal oscillator (TCXO) and crystal. The device includes a battery input that maintains accurate timing when the mains supply is disconnected. The integrated crystal oscillator increases the long-term accuracy of the device and reduces the number of components in the production line. The DS3231 is available in both commercial and industrial temperature ranges and is available in a 16-pin 300 mil SO package.
   The RTC saves seconds, minutes, hours, weeks, dates, months, and years. For months less than 31 days, the date of the month will be automatically adjusted, including the correction for the leap year. The working format of the clock can be 24 hours or a 12-hour format with /AM/PM indication. Two configurable calendar alarms and a configurable square wave output are available. The address and data are transmitted serially via the I2C bidirectional bus.
   A precision, temperature-compensated voltage reference and comparator circuit monitors the VCC status, detects power failures, provides a reset output, and automatically switches to the backup supply when necessary. In addition, the /RST monitor pin can be used as a manual input to generate a μP reset.
　 In addition to high timing accuracy, the DS3231 has additional features that extend the additional features and options of the system's mainframe. The device integrates a very accurate digital temperature sensor that can be accessed via the I2C* interface (as time passes). This temperature sensor has an accuracy of ±3 °C. The on-chip control circuitry enables automatic power detection and manages power switching between the primary and backup power supplies (ie, low voltage batteries). If the main power supply is powered down, the device will continue to provide accurate timing and temperature without compromising performance. The on-chip reset function can be used to restart the system microprocessor when the main power supply is re-energized or the voltage value returns to within the allowable range.

Module parameters:
1. Size: 38mm (length) * 22mm (width) * 14mm (height)
2. Weight: 8g
3. Operating voltage: 3.3--5.5V
4. Clock chip: high-precision clock chip DS3231
5. Clock accuracy : 0-40 ° C, accuracy 2ppm, annual error of about 1 minute
6. With 2 calendar alarms
7. Programmable square wave output
8. Real-time clock produces seconds, minutes, hours, weeks, dates, months and years, And provide the leap year compensation valid until 2100.
9. The chip has its own internal temperature sensor with an accuracy of ±3 °C.
10. Memory chip: AT24C32 (storage capacity 32K)
11. IIC bus interface, the maximum transmission speed is 400KHz (when the working voltage is 5V) )
12. the other IIC devices may be cascaded, by shorting 24C32 address A0 / A1 / A2 modify default address is 0x57
13. LIR2032 with rechargeable battery, to ensure the system is powered down, then any normal walking clock
14. packing: Single anti-static package
wiring instructions (take Arduino uno r3 as an example):
SCL → A5
SDA → A4
VCC → 5V
GND → GND