This real-time clock module (RTC) uses the DS3231 chip that integrates a crystal resonator and a temperature compensator, which improves the long-term accuracy of the module. In the range of -40°C to +85°C, the accuracy of DS3231 remains at ±3.5ppm (±0.3024 seconds/day).

The device incorporates a battery input, and maintains high precision timing when main power to the device is interrupted. The RTC provides information of seconds, minutes, hours, week, day, month and year, and it can automatically adjust the date at the end of the month, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. Two programmable time-of-day alarms and a programmable square-wave output are provided. In addition, the RST pin can be used as a push-button input for microprocessor reset.

NOTE: Due to the latest air cargo regulations, the transport audit of special items such as batteries, magnets and liquids will become very strict, so this RTC module does not come with batteries anymore, please buy them locally. The button cell battery model that goes with the module is CR1220.

Connection-Diagram

Board-Overview

DS323X Selection Guide

• Internal integrated crystal resonator, small deviation
• Internal integrated temperature compensator, small temperature drift
• Complete clock calendar function
• Two programmable Time-of-Day alarms

• Event reminder
• MCU external wakeup source
• Clock and alarm output

• Power Supply Voltage: 3.3V-5.5V
• I2C Address: 0x68
• Timing Range: 1970 ~ 2100
• Working Temperature: -40℃ ~ +85℃
• Timing Accuracy: ±3.5ppm (±0.3024 seconds/day)
• Product Size: 22.5*21mm / 0.89*0.83 inch

• Product wiki

• Fermion: DS3231 Precise RTC (Breakout) x1
• 2.54-7P Black Single Row Connector x1