DFROBOT Gravity I2C SD2405 Real Time Clock (RTC) Module

The DFROBOT Gravity I2C SD2405 RTC Module provides an extremely accurate I2C real-time clock, perfect for projects requiring precise and persistent timekeeping. It features an integrated, rechargeable battery, crystal compensation, and a high-precision time trimming circuit that automatically adjusts for any errors in the crystal oscillator frequency, ensuring long-term accuracy.

This versatile module can generate periodic interrupt clock pulses for up to one year and supports three separate alarm interrupts configurable by year, month, date, day of the week, hour, minute, and second. It offers a selectable clock output from 32.768 kHz down to 1 Hz for synchronising external microcontrollers, alongside a programmable square-wave output and a countdown timer interrupt function.

Key Features & Specifications

• High Accuracy: Features a time trimming circuit for crystal oscillator error correction.
• Comprehensive Timekeeping: Counts seconds, minutes, hours, day, date, month, and year with leap year compensation valid up to 2100.
• Flexible Alarms: Three configurable alarms based on time-of-year, month, day, week, hour, minute, and second.
• Versatile Output: Programmable square-wave and selectable clock output (32.768 kHz–1 Hz).
• Wide Voltage Range: Operates from 3.3V to 5.5V.
• Low Power Consumption: Typical current draw of just 1µA when powered by the internal battery.
• Fast Communication: Utilises a fast 400 kHz I2C interface.
• Compact Design: Board dimensions of 22 x 36 mm.
• Included Accessories: Comes with a Gravity I2C 4-pin sensor cable and an XH2.54 5-pin header for easy connection.

Ideal for embedded systems, electronics design, and Internet of Things (IoT) applications, this module delivers reliable, battery-backed timekeeping for your Arduino-compatible and other microcontroller-based projects.