Gravity: I2C DS1307 RTC Module

The Gravity: I2C DS1307 RTC Module is an easy-to-use real-time clock board designed for microcontrollers operating at 5V. It provides accurate timekeeping for data loggers, alarm clocks, and automation projects, making it ideal for students, makers, and educators.

Accurate timekeeping and calendar data

The module features an upgraded high-precision crystal oscillator with a tested time error of approximately 1 second over 24 hours. It tracks seconds, minutes, hours, day, week, month, and year with automatic leap-year compensation valid up to the year 2100, plus a dedicated 1Hz output pin.

Standard Gravity I2C interface

Operating at 5V, the board connects via a Gravity PH2.0-4P connector or standard XH2.54 pins for direct use with Arduino and expansion shields. The I2C address can be configured using resistance adjustment, and it is fully supported by the DFRobot Arduino DS1307 library.

Onboard non-volatile memory storage

In addition to tracking time, the module includes a 4KB EEPROM and 56 bytes of non-volatile RAM available for user data. This extra storage allows you to log custom parameters, event logs, and alarm settings directly on the board.

Long-life battery backup

The real-time clock circuit is designed to run on a single CR1220 coin cell battery with an estimated service life of 3 to 5 years. Please note that the CR1220 battery is not included and must be sourced separately.

Compact form factor and accessories

Measuring just 22mm by 27mm and weighing only 6g, this compact module easily integrates into space-constrained enclosures. Each package includes the RTC board, a Gravity 4-pin I2C/UART sensor cable, and an XH2.54 5-pin header.

Downloads & documentation

• Product wiki (DFRobot)