Equipment info wrong

[Linus Torvalds]

On Mon, Sep 21, 2015 at 3:30 PM, Guido Lerch <guido.lerch at gmail.com> wrote:
<
> Has someone recently changed something to the equipment info.
> Reading a dive from my Uemis today the first time since I test the end
> pressure in the equipment info is wrong.

I just got the same thing, and my SAC rate was hugely worse than it
should be, because the end pressure for the dive was recorded as 1.94
bar, even though the *display* shows 108.05 bar. Small difference
between tank half full, and tank at ambient pressure.

And it turns out that the pressure reading of 1.94 bar is actually
technically correct, it's just that the Uemis downloader seems to have
changed. The end of that dive looks like this:

   ...
   57:44 2.67m 109.68bar
   57:47 2.67m 109.57bar
   57:52 2.58m 109.48bar
   58:00 2.56m 109.38bar
   58:03 2.33m 109.24bar
   58:08 2.37m 109.16bar
   58:16 2.16m 109.05bar
   58:19 1.89m 108.96bar
   58:24 2.09m 108.88bar
   58:27 2.13m
   58:32 1.95m 108.78bar
   58:40 1.57m 108.58bar
   58:43 1.48m 108.49bar
   58:48 0.0m
   ...
   60:56 0.0m 108.0bar
   60:59 0.0m 29.5°C 108.02bar
   61:04 0.0m 108.03bar
   61:06 0.0m 29.4°C
   61:12 0.0m 29.5°C
   61:20 0.0m 108.05bar
   61:23 0.0m
   61:28 0.0m 108.06bar cns=4%
   61:36 0.0m
   61:39 0.0m
   61:44 0.0m
   61:47 0.0m
   61:52 0.0m 56.11bar
   62:00 0.0m 29.06bar
   62:02 0.0m 1.94bar
   62:08 0.0m
   62:14 0.0m

ie I came to the *surface with 108 bar, but then a couple of minutes
later I turned off my air and depressurized the regulator. The Uemis
has helpfully saved all of that, and while we don't *display* the
surface events at the end, the "end pressure" calculations and the SAC
calculations do actually see it.

I *think* the old Uemis downloader used to just ignore pressure events
at the surface, because I don't recall having seen this before. So I
suspect it's actually your Uemis changes that caused this.

At the same time, I think we should just ignore the pressure data from
the surface. It's not meaningful, regardless of whether you
depressurize the regulator or not, since you'd presumably be breathing
the surface air, not from the cylinder. So surface time shouldn't
count towards the SAC, and likewise is meaningless for "end pressure"
as exemplified above.

So I'll fix the generic code, and we can let the Uemis downloader be.

                Linus