This device has a temperature sensor with 0.25°C precision, and an "aging offset" which can be used to calibrate the crystal
frequency for increased timekeeping accuracy.
With these changes, I was able to use a precision frequency meter to "tune" the RTC so that it would have less than .01 seconds per day of error at 27°C, by assigning the best value to the calibration register.
This device has a temperature sensor with 0.25°C precision, and an "aging offset" which can be used to calibrate the crystal frequency for increased timekeeping accuracy.
Expose these as properties.
This requires https://github.com/adafruit/Adafruit_CircuitPython_Register/pull/39 as the temperature and calibration registers hold signed values.
With these changes, I was able to use a precision frequency meter to "tune" the RTC so that it would have less than .01 seconds per day of error at 27°C, by assigning the best value to the calibration register.