Clock fast on Giga R1

[schnoberts]

I guess this is what I should have read before starting

[solved] Highly accurate Arduino time via RTC pulse to update seconds?

I found a great post here: "How to get a more accurate RTC clock set from a NTP time server" Wonderful! I love accurate clocks... I Implemented the NTP modification to get the fractional time part (milliseconds) Then I wired up my DS3231's SQW pin to an interrupt. Now I have on the FALLING edge exactly the start of a new scond I thus SET the Arduino time_t t at that precise moment using RTC time so I am not dependent on the oscillator of the Arduino It does work but I'm learning a lot wit…