SPECIFICATIONS

DS3231 is a low-cost,high-precision I2C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. This device includes a battery input,allowing it to maintain accurate timekeeping even when the main power supply is disconnected. The integrated crystal improves the device's long-term accuracy and reduces the number of components on the production line. The DS3231 is available in commercial and industrial temperature ranges and comes in a 16-pin 300mil SO package.

The RTC keeps track of seconds,minutes,hours,day of the week,date,month,and year information. For months with fewer than 31 days,the date is automatically adjusted,including corrections for leap years. The clock operates in either 24-hour format or 12-hour format with AM/PM indication. It provides two programmable calendar alarms and a programmable square-wave output. Address and data are transferred serially via the I2C bidirectional bus.

A precision,temperature-compensated voltage reference and comparator circuit monitor the VCC status,detect power failures,provide a reset output,and automatically switch to the backup power supply when necessary. Additionally,the /RST monitoring pin can be used as a manual input to generate a μP reset.

In addition to high timekeeping accuracy,the DS3231 offers several other features that extend the functionality and options for the system host. The device integrates a highly accurate digital temperature sensor,which can be accessed via the I2C interface (similar to time). The accuracy of this temperature sensor is ±3°C. The on-chip control circuitry enables automatic power detection and manages the power switching between the main power supply and the backup power supply (i.e.,low-voltage battery). If the main power supply fails,the device continues to provide accurate timekeeping and temperature readings without performance degradation. When the main power supply is restored or the voltage returns to an acceptable range,the on-chip reset function can be used to restart the system microprocessor.

Module Parameters:

• Dimensions: 38mm (L) * 22mm (W) * 14mm (H)

• Weight: 8g

• Operating Voltage: 3.3–5.5V

• Clock Chip: High-precision clock chip DS3231

• Clock Accuracy: 2ppm within the range of 0-40°C,annual error approximately 1 minute

• Two calendar alarms

• Programmable square-wave output

• Real-time clock generates seconds,minutes,hours,day of the week,date,month,and year timekeeping,with leap year compensation valid until 2100

• Built-in temperature sensor with an accuracy of ±3°C

• Storage Chip: AT24C32 (32K storage capacity)

• IIC bus interface,maximum transmission speed 400KHz (when operating voltage is 5V)

• Can be cascaded with other IIC devices,24C32 address can be modified by shorting A0/A1/A2,default address is 0x57

• Uses CR2032 battery to ensure the clock continues to run normally after a power outage

Wiring Instructions (using Arduino Uno R3 as an example):

1. SCL → A5

2. SDA → A4

3. VCC → 5V

4. GND → GND