In my Application I want to make a kind of auto-calibration of the internal RTC. I want avoid (if possible) to use external equipment for the calibration. My idea is to use the Smooth calibration with 32 second calibration window. I want to check the correct 32 second using an internal timer (clocked by Sytem Clock). There is someone with success in this ?
Speaking with Application Field Engineering of ST, normally the suggested oscillator with suggested capacitors should be used in the board design. With the suggested components the RTC should be very precise. Is possible to create an auto-calibration using the main clock but only if this is generated from a very high precision oscillator.