PPO2 Values Missing

Discussions about Diving Log 6.0 - questions and hints
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RVbldr
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Joined: Thu Dec 20, 2012 19:31

PPO2 Values Missing

Post by RVbldr » Tue Jan 15, 2019 04:46

I see some older threads on missing PPO2 values, but I'm curious if this has a fix. It looks like my Petral 2 has imported Setpoints, but the Profile 5 PO-1 -> PO-3 values are all 0. Looking at the Shearwater desktop, I do see mV values being recorded for each sensor. I've been able to import the dive from Shearwater Desktop, and it appears to import an average PPO2 and fills the PO-1 column, but the other two sensors are not imported.

I see there's some comments about not recording PPO2 for individual sensors if the calibration value is set to DEAULT. I'm unable to find the libdivelog log file to verify if there's an entry for this state. Any help?

divinglog
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Re: PPO2 Values Missing

Post by divinglog » Thu Jan 17, 2019 14:24

Diving Log can only store and dispaly PPO2 values in bar, not mV. It might be possible that the Petral does not provide the bar values, so they cannot be downloaded directly from the dive computer. Shearwater Desktop probably calculates an average PPO2 in bar from the mV values and these are imported into Diving Log.

As far as I know, libdivecomputer does not support mV values either, so it needs bar values to be transfered to the application.

RVbldr
Posts: 21
Joined: Thu Dec 20, 2012 19:31

Re: PPO2 Values Missing

Post by RVbldr » Fri Jan 18, 2019 02:18

So I'm guessing that the only solution is to sync with Shearwater Desktop, then import those dives to DL? Per SW Desktop, we can see the three O2 sensor values, and the average PPO2 in the graph. I'd think for CCR, it's interesting to have this data from any unit, and with Shearwater Divecan getting fairly common across manufacturers, I'd think this feature would be potentially implemented.
PPO2 SWD.JPG
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divinglog
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Re: PPO2 Values Missing

Post by divinglog » Sat Jan 19, 2019 16:28

Diving Log can only import data that is available. I've found this explanation from Jef Driesen:
Libdivecomputer supports reporting ppO2 from the O2 sensors. But on some shearwater devices the calibration values (which are needed to convert from millivolt to the ppO2 value) are not stored correctly, and are left at their default values. If that's the case, then libdivecomputer disables the ppO2 values instead of reporting invalid ppO2 data. This is a fairly recent change, so this might be the issue Morten is experiencing after upgrading to a newer libdivecomputer version. There should be a warning "Disabled all O2 sensors due to a default calibration value." in the libdivecomputer log.
What you're seeing in your screenshot are the mV values from the three sensors (when you move the cursor over the profile, it should be visible in the popup overlay). I have only a screnshot of Cloud Desktop, but in Shearwater Desktop it's the same:

Image1.png
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