Review request: mCCR diving with OSTC3 fixed setpoints

Jan Mulder jlmulder at
Fri Apr 28 09:56:28 PDT 2017

On 28-04-17 14:12, Jan Mulder wrote:
> Let me first explain the use case. I (and some fellow cave explorers I 
> dive with) dive mCCR units (Kiss Classic specifically) in its most 
> primitive form. No attached divecomputer to the mCCR, but only some 
> analog po2 devices to fly the unit. This obviously results in no 
> logging from po2 sensors. I use a OSTC3, and most of my buddies some 
> Shearwater divecomputer. As I am (at this point), not aware how a 
> Shearwater handles this use case, I consider only an OSTC3 for now.
> it appears, in the current code, the manual changes of setpoint on the 
> divecomputer are correctly recorded (as events) and are correctly 
> handled on import from the OSTC3 in to Subsurface. The initial 
> setpoint  at the start of the dive is, however, a little bit  a can of 
> worms. The OSCTS3 does not record a setpoint change at the beginning 
> of the dive, and the recorded po2 values are from the diluent (so not 
> very useful).
> To deal with this use case, had to adapt libdivecomputer (see my 
> branch, and after 
> that Subsurface 
> (
> As libdivecomputer did not interface the fixed setpoints (including 
> the initial one at the start of the dive), I had to add those. After 
> that, Subsurface can determine the initial setpoint. For completeness, 
> this setpoint is added to the XML and git storage backends as well.
> I would really appreciate a review for this change.
> best,
> --jan
The short remark of Jef changed basically everything. So I replaced my 
adapted libdivecomputer branch completely (but still under the same 
name, sorry to anybody who already pulled it). The concept of the change 
is now very simple.  Libdivecomputer just puts the initial setpoint in 
OSTC3 CCR mode in the first sample, and now Subsurface is now working 
straight from the box.

So anybody who wants to take a look, the updated code is now at, and there is no 
update in Subsurface required anymore.

As a "bonus", also the battery percentage data that is recently added by 
HW to the logbook of the OSTC3, is now also visible in Subsurface.

And finally a question for Jef: how do I submit commits for libdivecomputer?



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