Allow user to select dive mode (including PSCR)

[Anton Lundin]

On 16 January, 2015 - Robert Helling wrote:

> Hi,
> 
> first of all, here are more patches towards the PSCR mode:
> 
> 
> > On 12.01.2015, at 12:25, Davide DB <dbdavide at gmail.com> wrote:
> > 
> > Hi Robert,
> > 
> > Could you shed some light on how to use pSCR feature?
> 
> In logbook mode: Just turn it on using the combo box.
> 
> It implicitly also adds a set-point change at t=0 to the default stepping for CCR mode and 0 for all other modes. Similarly in planner.
> 
> > Which formula did you use?
> 
> The steady state formula. You find in dive.c lines 1689ff
> 
> 		if (divemode == PSCR) { /* The steady state approximation should be good enough */
> 			pressures->o2 = get_o2(mix) / 1000.0 * amb_pressure - (1.0 - get_o2(mix) / 1000.0) * prefs.o2consumption / (sac * prefs.pscr_ratio / 1000.0);
> 			pressures->he = (amb_pressure - pressures->o2) * get_he(mix) / (1000.0 - get_o2(mix));
> 			pressures->n2 = (amb_pressure - pressures->o2) * (1000 - get_o2(mix) - get_he(mix)) / (1000.0 - get_o2(mix));
> 		} else {
> 
> > Where I set needed constants?
> 
> Currently, there is no UI to set them unfortunately, there is only subsurfacestartup.c
> 
> 	.o2consumption = 720,
> 	.pscr_ratio = 100,
> 
> 

I completely understand if they are in prefs "for now", but i think they
should but shouldn't we save these as a "per-dive" ratio?


As a side-note, I think the o2 consumption should default to something a
tad higher, about 1000ml or so is probably a good default, and i don't
know which pscr who have a 1/10 dump ratio, but the rb80 have 1/8 dump
ratio and my guess is that it and its clones are the most common pscr on
the market.


//Anton


-- 
Anton Lundin	+46702-161604