Hi,

I am looking to use the DS3231 I2C RTC for a data logging project and I have been trying and failing to find a nice way to find out when the next nice round 5 Minute time value is reached....

The RTC can give total seconds since the begining of time itself (ie year 2000) with

**now.get()**2012/12/6 18:26:11 Fri

Seconds since 1/1/2000: 408133571

I am hoping to find the next round 5 minute time value and start logging from then:

So the time I am interested in, relative to the time above, would be 18:30:00.

Any idea how I would calculate a new 'rounded seconds count value' (ie the 408133571 number) so that I can evaluate it against the current time and then proceed when one equals the other?

long now = 408133571

long rounded = 40813xxxx ?

If now = rounded then..... do something.

Thanks for any help.