The Adafruit DS3231 I2C Precision Real Time Clock FeatherWings are extremely accurate real-time clocks (RTC) that feature temperature controlled crystal oscillators (TCXO). With the crystal inside the main chip and a temperature sensor right next to it, clock ticks can be dropped or added to compensate for drift caused by temperature changes. The chip is claimed to be accurate to ±2ppm which is equivalent to one second every 5 days or one minute per year. Which is pretty accurate. There's a coin cell holder on each board suitable for a CR1220 battery which can keep the clock ticking for years.
Adafruit supply a free tutorial and software library to get you started. Supplied as a fully assembled and tested board plus strips of 0.1in. header pins for you to solder on as required. The battery is not included but we have a lot of batteries.
Extremely accurate temperature compensated RTC
Quoted accuracy ±2ppm
Add-on for all Feather boards
Dimensions 50.8 x 22.9 x 1.6mm (2 x 0.9 x 0.06in.)
Adafruit part no.: 3028
*Customers looking to resell on eBay or Amazon should contact Adafruit directly.
