I am experimenting with this idea: keep a DTCXO in sync with some frequency standard. I have all the parts I can afford, but I cannot figure out a way to do it.
Parts I have: Arduino Leonardo, a
u-blox 6010 based GPS module with PPS output, and a proto shield with
DS3231 DTCXO chip mounted.
My big idea is that
DS3231 have aging registers that would affect the clock frequency. By keep counting the 8192Hz square wave output of
DS3231 and keep it in sync with the 1Hz signal from the GPS module, I can keep the DTCXO in sync with a reference clock. This, in turn, would give me a relatively good 32768Hz clock reference that I can build a frequency counter on.
Both 8192Hz and PPS are interrupt driven.
Anyone have an idea on how to do it? Does this spell Artificial Intelligence on AVR, as my instructor suggests?