Grove - High Precision RTC


3.3V 5.0V I2C

Grove - High Precision RTC based on the clock chip PCF85063TP which is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption. An offset register allows fine-tuning of the clock. All addresses and data are transferred serially via the I2C bus and the maximum bus speed is 400 kbit/s.

Compared to Grove - RTC, this module can provide a more accurate result. And provide a programmable clock output for peripheral devices as well as minute and half minute interrupt.


  • Working Voltage:5V/3.3V
  • Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal
  • Low current: typical 0.22 uA at VDD = 3.3 V and Tamb = 25 ℃
  • 400 kHz two-line I2C-bus interface (at VDD = 1.8 V to 5.5 V)
  • Programmable clock output for peripheral devices (32.768 kHz, 16.384 kHz, 8.192 kHz, 4.096 kHz, 2.048 kHz, 1.024 kHz, and 1 Hz)
  • Minute and half minute interrupt
  • Oscillator stop detection function
  • Internal Power-On Reset (POR)
  • Programmable offset register for frequency adjustment
  • Interface:Grove - I2C(SCL,SDA,VCC,GND)
  • Size:20*40mm
  • Ready-to-go Arduino libraries

Platforms Supported

Interface Function

  1. Grove interface
  2. Programmable clock output interface
  3. Minute and half minute interrupt output interface
  4. Clock chip PCF85063TP
  5. CR1225 battery-holder

Application Ideas

  • Digital still camera
  • Digital video camera
  • Printers
  • Copy machines
  • Battery powered devices

Getting Started

After this section, you can make Grove - High Precision RTC run with only few steps.


Now we are making a demo for Grove - High Precision RTC module, in this demo we’ll use a terminal to view the data. Here are what we need to use for this demo.

If this is your first time using Seeeduino Lotus, please refer to Seeeduino Lotus’s wiki.

Seeeduino Lotus is fully compatible with Arduino which works as simple as Arduino.

If this is your first time using Arduino, Please put hand on here to start your Arduino journey.

Connecting hardware

Seeeduino Lotus is a combination of Seeeduino and Base Shield. We can connect the RTC module to the I2C socket directly as the below picture shows.

Download the library

Click to download the library and install it (How to install an Arduino Library).

Open the example

After install the library, please restart Arduino, click File>Examples>SetTimeAndDisplay.

Review Results

After upload completed, you can open the serial monitor to see the result.


ArduinoWioBeagleBoneRaspberry PiLinkIt ONE


The platforms mentioned above as supported is/are an indication of the module's hardware or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Help us make it better

Thank you for choosing Seeed. A couple of months ago we initiated a project to improve our documentation system. What you are looking at now is the first edition of the new documentation system. Comparing to the old one, here is the progresses that we made:

  • Replaced the old documentation system with a new one that was developed from Mkdocs, a more widely used and cooler tool to develop documentation system.
  • Integrated the documentation system with our official website, now you can go to Bazaar and other section like Forum and Community more conveniently.
  • Reviewed and rewrote documents for hundreds of products for the system’s first edition, and will continue migrate documents from old wiki to the new one.

An easy-to-use instruction is as important as the product itself. We are expecting this new system will improve your experience when using Seeed’s products. However since this is the first edition, there are still many things need to improve, if you have any suggestions or findings, you are most welcome to submit the amended version as our contributor or give us suggestions in the survey below, Please don’t forget to leave your email address so that we can reply.

Happy hacking