Real Time Clock (Qwiic) - RV-1805

We're clearing out the black SparkX version of this board so pick one up while they're cheap! Other than color there is no difference between this board and its red cousin.

The Qwiic RTC from SparkFun is a very unique and exciting Real Time Clock. It is extremely precise (within 3 minutes over a year!), extremely low power (less than 22nA!) and has all the necessary oscillators and back-up power making it very compact.

The RV-1805 from Micro Crystal has not one, but two internal oscillators: a 32.768kHz tuning fork crystal and a low power RC based oscillator. The RV-1805 automatically switches between oscillators using the more precise crystal to correct the RC oscillator every few minutes. This allows the RTC to maintain a very accurate date and time with the worst case being +/- about 3 minutes over a year. Very few RTCs can come close to this.

The RV-1805 and the library we've written operate the RTC at 22nA. This is extremely low power. No external battery needed! We've included a 0.22F super cap on the Qwiic RTC. This should maintain the RTC for over 170 days (nearly 6 months) but we have not had 6 months to test this. For now, we guarantee the super cap will maintain the RTC for over a month. That means you can let board sit with no power or connection to the outside world and the current hour/minute/second/date will be maintained. The RV-1805 RTC has a built in trickle charger: as soon as the RTC is connected to power the super cap will begin to charge and will be fully charged in under 10 minutes. Now you'll never have to worry about how much longer your coin cell may last!

The RV-1805 has an alarm and timer capability. This allows the user to set various alarms and generate interrupts when a certain time is achieved.

Lastly, and perhaps most interestingly the RV-1805 has the ability to switch power to other systems. The RV-1805 has a PSW pin that can sink up to 50mA. This allows it to directly turn on or off a power hungry device such as a microcontroller or RF engine. The RV-1805 can be configured to power up/down the device based on time or external interrupts.

The Qwiic-RTC uses the simple Qwiic interface. No soldering, no voltage translation, no figuring out which pin is SDA or SCL, just plug and go!

We do not plan to regularly produce SparkX products so get them while they’re hot!

Experimental Product: SparkX products are rapidly produced to bring you the most cutting edge technology as it becomes available. These products are tested but come with no guarantees. Live technical support is not available for SparkX products. Head on over to our forum for support or to ask a question.
  • Precise time keeping with variance of +/-3minutes across 1 year
  • Low 22nA standby current
  • On board 0.22F super cap capable of RTC maintenance for nearly 6 months
  • Square wave output
  • Configurable alarm generation
  • Capable of powering on/off other peripherals with very low power

Real Time Clock (Qwiic) - RV-1805 Product Help and Resources

Qwiic Real Time Clock Module (RV-1805) Hookup Guide

May 31, 2018

Find out what time it is, even after the power's been out on your project for a while with the Qwiic Real Time Clock (RTC) module.


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

Customer Reviews

5 out of 5

Based on 1 ratings:

Currently viewing all customer reviews.

No Battery!!!

Works great and doesn't care if it's been in the parts drawer for a year (or two). If the power goes out - it just keeps the clock going until the power is back returns. Charges itself!