Unable to get O2 cell data after update

3rd party extensions (phpDivingLog, dive computer downloader,...)
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Danish Diver
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Unable to get O2 cell data after update

Post by Danish Diver » Thu May 10, 2018 07:56

Hi,

I am using a Shearwater petrel 2, on my JJ rebreather, but after the latest Diving Log update, I am unable to get the O2 readings. Before I was able to go to “profile data” – "Profile 5" and here I was able to get the reading of cell 1. Now I cannot get this data!

In the future, I would appreciate the readings from all three cells.

Morten Didriksen

divinglog
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Re: Unable to get O2 cell data after update

Post by divinglog » Thu May 10, 2018 12:29

Hi Morten

Do you download the dive computer directly with Diving Log? The only thing that has changed is libdivecomputer. If you want, you can download the previous libdc version from here. Copy the content of the zip file into the Diving Log 6.0 program folder. Let me know if you get the cell data again.

You can also try to import from Shearwater Desktop to see if you receive all 3 cells. Then it should be possible to also implement this in libdivecomputer.

Kind regards,
Sven

TnT
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Re: Unable to get O2 cell data after update

Post by TnT » Thu May 10, 2018 12:49

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.
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Buceador
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Re: Unable to get O2 cell data after update

Post by Buceador » Sun Jun 30, 2019 18:11

As I understood from another post, the problem is that the divecomputer stores the data from the three cells in mV and that these values are not loaded. Am I right? Are there any future plans to incorporate this? I would very much appreciate this.

Other values I can see in the Shearwater desktop app is the battery voltage. Is this also for the same reason not available?

Thanks!

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Re: Unable to get O2 cell data after update

Post by divinglog » Mon Jul 01, 2019 13:27

TnT wrote:
Thu May 10, 2018 12:49
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.
As Jef wrote, normally PO2 values are calculated by libdivecomputer, but if the calibration value is missing, the conversion from mV to bar is not possible. I don't know when or why this value is missing. Diving Log cannot store mV values, only bar values. You can try to import from Shearwater Desktop or Cloud Desktop. If there is PO2 data, it will be imported that way.
Buceador wrote:
Sun Jun 30, 2019 18:11
Other values I can see in the Shearwater desktop app is the battery voltage. Is this also for the same reason not available?
Even if libdivecomputer would report those, there is currently no place in Diving Log to store them.

RVbldr
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Re: Unable to get O2 cell data after update

Post by RVbldr » Fri Aug 16, 2019 04:20

Is it possible to just display the mV data instead of the PO2 (assuming the calibration value is missing). I'm not finding that data available in the log.

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Re: Unable to get O2 cell data after update

Post by divinglog » Fri Aug 16, 2019 12:11

Unfortunately there is no profile data slot for mV right now.

RVbldr
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Re: Unable to get O2 cell data after update

Post by RVbldr » Sun Sep 15, 2019 14:36

For CCR, it looks like Profile 5 shows PPO2 for three cells, but from a previous post, it seems to need the calibration constant which is applied to Milli-volts to calculate PPo2? So in reality we can't get either PPOs or Mv imported from the Shearwater? Are there any plans to at least capture mV readings - At least we can track mV over time to identify cells that might be starting to diverge. I believe we can import PPO2, but we need to sync with Shearwater Desktop, then export -> import to Diving Log.

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Re: Unable to get O2 cell data after update

Post by divinglog » Sun Sep 15, 2019 18:39

From my understanding, the calibration value is normally there in order to calculate the PO2 with libdivecomputer. But there are circumstances where this value might be missing for some reason. Jef Driesen may be able to explain why this might happen.

But you can import from Shearwater Desktop directly (no export required). So you can download with Shearwater Desktop, then import directly.

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