High Precision Real Time Clock for Raspberry Pi DS3231 RTC

$12.00 Inc. GST
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The popular Raspberry Pi computer unfortunately lacks a real time clock. This is a high precision Real Time Clock (RTC) module for the Raspberry Pi, Compatible with all Raspberry Pi models, the Pi 3, Pi 2, B+, and original Model B. Designed to connect directly to the Raspberry Pi GPIO port with an ultra small footprint.

The DS3231 is a low-cost, extremely accurate I2C real- time clock (RTC) with an integrated temperature- compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accu- rate timekeeping when main power to the device is inter- rupted. The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line. The DS3231 is available in commercial and industrial temperature ranges, and is offered in a 16-pin, 300-mil SO package.

The RTC maintains seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator. Two programmable time-of- day alarms and a programmable square-wave output are provided. Address and data are transferred serially through an I2C bidirectional bus.


  • Accuracy ±2ppm from 0°C to +40°C
  • Accuracy ±3.5ppm from -40°C to +85°C
  • Battery Backup Input for Continuous Timekeeping
  • Operating Temperature Ranges - Commercial: 0°C to +70°C, Industrial: -40°C to +85°C
  • Low-Power Consumption
  • Real-Time Clock Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
  • Two Time-of-Day Alarms
  • Fast (400kHz) I2C Interface
  • 3.3V Operation
  • Digital Temp Sensor Output: ±3°C Accuracy
  • Register for Aging Trim
  • RST Output/Pushbutton Reset Debounce Input

Check out the blog post here on how to use it with Raspbian on a Raspberry Pi.

Note: Raspberry Pi not included.

12 comments on "High Precision Real Time Clock for Raspberry Pi"
  1. Him

    Can you please tell me what the pins are on this? And if there is an alarm/int pin broken out is it connected the the 32kHz pin ot the ALARM/INT pin on the ds3231?

  2. Him

    Can you please tell me what the pins are on this? And if there is an alarm/int pin broken out is it connected the the 32kHz pin ot the ALARM/INT pin on the ds3231?

  3. Hi there,

    Just SDA SCL and power, there are no other pins broken out on this module.


  4. Pending moderation
  5. Pending moderation
  6. Hi there,

    Is this product only compatible with earlier Pi versions or has the description not been updated since newer units have been released?

    I would much rather use this with my Pi 3 as opposed to my vero board RTC

    Thank you
  7. Hi Nicole,

    It works with all the Pi models including the Pi 3 - we've just been a bit slack updating the description which I've done now.


  8. Hi there,

    The description explain that "programmable square-wave output are provided"
    Could you explain how this trigger work and how we can use it ?

  9. Hi Mike,

    It looks like that pin isn't broken out on this particular board.


  10. Battery included?
  11. Soldered on.
  12. Ah. Yuck.

    Thank you.

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