The Adafruit DS3231 Precision RTC Breakout contains an exceedingly accurate I²C-Integrated RTC/TCXO/Crystal inside the chip, meaning this is the one of the best RTC’s you can get a hold of on a consumer store.
Please note, a coin cell is required to use the back-up battery, due to shipping limitations it is not included as part of the item. Will work with any CR1220 you have at hand.
Most RTCs use an external 32kHz timing crystal that is used to keep time with low current draw. And that’s all well and good, but those crystals have slight drift, particularly when the temperature changes (the temperature changes the oscillation frequency very very very slightly but it does add up!) This RTC is in a beefy package because the crystal is inside the chip! And right next to the integrated crystal is a temperature sensor. That sensor compensates for the frequency changes by adding or removing clock ticks so that the timekeeping stays on schedule.
Be sure to check out AdaFruits full hook-up guide below for information on installation and coding, Hail Lady Ada!
DS3231 Precision RTC Documents
- Full Hook-up Guide courtesy of AdaFruit!
- EagleCAD PCB files on GitHub
- Fritzing object available in the Adafruit Fritzing Library