32.768KHz crystal calibration

[yingchc]

I use nRF52832 with 32.768KHz crystal, is that possible to make the frequency error smaller than 5 ppm by calibration or doing something?

[hmolesworth]

MSP430 RTC Temperature Compensation.pdf

I wrote this a few years ago, it might provide some ideas iff you want to explore further. The target was MSP430, but it applies equally to any cpu.

; TI produced an app note based in part on this entry, but I don't have the link to hand.