DFRobot
Gravity: I2C SD2405 RTC Module
A high-precision I2C real-time clock (RTC) module from DFRobot's Gravity series, based on the SD2405AL chip. It features an internal rechargeable battery tha...
A high-precision I2C real-time clock (RTC) module from DFRobot's Gravity series, based on the SD2405AL chip. It features an internal rechargeable battery that keeps time for 5–8 years without external power, making it ideal for data logging, alarm clocks, and any project that needs reliable timekeeping.
The module includes crystal compensation for ±5 ppm accuracy across industrial temperature ranges, automatic power switching between primary and battery power, and a Gravity I2C connector for plug-and-play wiring.
Key Features
- Internal Rechargeable Battery – Keeps time for 5–8 years without external power
- High Accuracy – ±5 ppm from -40°C to +85°C with crystal compensation
- Ultra-Low Power – 1 µA typical on battery (at 25°C)
- Automatic Power Switching – Seamless switchover between primary and battery power
- Three Alarm Interrupts – Configurable by year, month, date, day, hour, minute, second
- Programmable Clock Output – 32.768 kHz to 1/16 Hz square wave
- Countdown Timer – With interrupt output
- 12-Byte SRAM – General-purpose on-chip storage
- Gravity I2C Connector – Plug-and-play with Gravity-compatible boards
Specifications
- Operating Voltage – 3.3–5.5V
- I2C Speed – Up to 400 kHz (at 4.5–5.5V)
- Accuracy – ±5 ppm (-40°C to +85°C)
- Timing Range – Up to 2099 (with leap year compensation)
- Clock Output – Selectable 32.768 kHz to 1/16 Hz
- Time Format – 12-hour or 24-hour selectable
- Dimensions – 35.5 × 22 mm (1.4 × 0.87″)
- Weight – 6 g
Ideal For
- Data logging with timestamps
- Alarm clocks and timer applications
- Scheduled task triggering
- Any project requiring accurate, battery-backed timekeeping
Package Contents
- 1× Gravity I2C SD2405 RTC Module
- 1× Gravity I2C 4-Pin Sensor Cable
- 1× XH2.54 5-Pin Header
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- Gravity
- Gravity is DFRobot’s plug-in connector system for sensors, motors and modules, using standard cables to reduce loose jumper wiring. It matters because Gravity-compatible parts can connect directly to these ports, while non-Gravity parts may need adapters or manual wiring.
- I2C
- I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
- ppm
- ppm means parts per million, a common way to express very small gas concentrations in air. For CO₂ sensors, the ppm range tells you what levels the sensor can measure, such as normal indoor air through to poorly ventilated spaces.
- RTC
- A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.
- SD2405
- A real-time clock chip used to keep track of date and time even when the main controller is not actively running. In a data-logging kit, it helps timestamp measurements so readings on the memory card can be matched to when they were taken.
- SRAM
- Fast temporary memory used by a processor while a program is running. More SRAM helps with projects that handle larger data buffers, networking, displays, or more complex code.
Find this product in
Brands
Supplier page — dfrobot.com
Supplier Description · 551.5 KB · Click any page to view full size
Related Tutorials
Free guides on learn.littlebird.com.au
