Suunto EON sample interval

Miika Turkia miika.turkia at
Thu Apr 30 06:51:36 PDT 2015

On Wed, Apr 29, 2015 at 10:50 PM, Linus Torvalds
<torvalds at> wrote:
> On Apr 29, 2015 20:25, "Miika Turkia" <miika.turkia at> wrote:
>> I am looking at a log from Suunto EON  Steel and it seems that it
>> generally has a 10 second sample interval.
> No. The eon steel gives time difference in the samples, and they are not ten
> seconds apart, they are given in *milliseconds* and while close to ten
> seconds they are not exactly that. I have the logs, but am not in front of
> my computer right now.

OK, so the drifting I see on our samples is due to this roughly ten
second interval spiced up with millisecond precision.

> So not only are things not at an even second to begin with, there are events
> that happen outside of the regular samples that may have timestamps that
> change things even more.

Interestingly it seems that these events record the previous depth,
not the current. Is EON recording only the event, no depth and your
importer adds the depth there?

> My eon importer keeps track of the time in milliseconds internally (it
> really has to - ask the times are incremental and in that format) but then
> exposes them in seconds (because that's the same format, and the
> libdivecomputer interface).
> So you'll never see the traditional "every x seconds" behavior.

Thanks, this explains quite a bit, but we will loose some precision
when exporting to interval based logs (e.g.  But I don't
think this will be significant to worry about.


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