Fermion: SD3031 Precision RTC Module for Arduino (Breakout)

The Fermion SD3031 Precision RTC Module is a reliable real-time clock breakout featuring an integrated crystal oscillator and temperature compensator for dependable timekeeping. With an ultra-low operating current and built-in SRAM, it is ideal for makers, students, and engineers developing IoT data loggers, timers, and battery-powered Arduino projects.

Accurate temperature-compensated timing

The onboard SD3031 chip combines an integrated crystal oscillator with temperature compensation to deliver timing accuracy of plus or minus 3.8ppm at 25 degrees Celsius. It tracks seconds, minutes, hours, days, dates, months, and years from 2000 to 2099, including automatic month-length adjustment and leap year correction.

Ultra-low power battery backup

The module requires just 1.8 microamps of timing current when running on battery backup, keeping accurate time even during main power outages. It also allows reading the button cell voltage, making it easy to monitor the state of the required CR1220 battery.

Integrated 70-byte SRAM storage

Featuring 70 bytes of internal SRAM, the breakout provides a low-power area to store essential variables and configuration data. This makes it particularly practical for compact IoT devices that periodically sleep to conserve energy.

Arduino Uno wiring and integration

Operating at 3.3V with an I2C interface at address 0x32, the compact 22.5 x 21mm breakout connects cleanly to microcontroller boards such as the Arduino Uno. It ships with a standard 2.54mm 7-pin header for fast prototyping on breadboards.

Versatile timing and wake-up applications

Designed for versatility, the SD3031 serves effectively as an external MCU wake-up source, event reminder, countdown device, and IoT data timestamping clock. Its small footprint and low drift ensure stable scheduling in diverse embedded setups.

Downloads & documentation

• Product wiki (DFRobot)