Time - Tenths of a second

Projects Programming
1

I'm looking to record real time when an action occurs.

I have an RTC and the time library. Is there an easy way to calculate these or do I need to implement some sort of timer interrupt synchronized with the seconds?

Thanks

2

You can use millis() or micros() to create tenths of a second in between the 1 second updates from the RTC.

3

the DS1307 (and perhaps others) have a SQW/OUT pin that you could set to 1Hz, synchronized with the seconds tick.

Drive a millis() counter reset on an interrupt, kind-of-thing

4

Thanks, sorted