Air and water temperature

Alexandre Belloni alexandre.belloni at piout.net
Fri Nov 11 19:12:07 PST 2011


On Fri, Nov 11, 2011 at 11:46:30AM +0100, Jef Driesen wrote :
> I agree with Linus that this is best done at the libdivecomputer
> level, where we know best how each model stores this kind of
> information.
> 

I kind of expected that answer. I'd like to help there but I don't know
much about dive computers other than Suunto's. Would you have any
preference for the implementation ?

> Adding extra fields such as temperature, begin/end pressure for each
> tank, etc is already on the (long) todo list. I haven't decided
> exactly on which fields to add, but the idea is to add only those
> fields that are available (or can be calculated from profile data)
> on a wide range of dive computers AND that are useful for a general
> purpose logbook application (e.g. like subsurface, which is not tied
> to a particular brand of dive computer). This means there won't be
> support for very device specific fields like personal adjustment
> factors, decompression settings, etc. This kind of information just
> varies too wildly to cover with a common api.
> 
> Even simply fields that appear quite generic can already be quite
> tricky. For example some dive computers store ascent rates as a
> simple value (eg. m/min), others as an index into a table (e.g. 0-5,
> 6-10, 11-15, 15+), or even just some fuzzy indication (e.g.
> slow/fast). This makes it very hard to define a single ascent rate
> representation. And there are many more examples like this.
> 
> But I don't think this type of info is that important too have,
> because fields like ascent rate, tissue loading, etc can easily be
> calculated from the profile data. These calculated values may not
> match exactly with what you would get from the dive computer, but
> I'm not convinced that is very important. I would prefer to
> concentrate on those fields that really matters, like divetime,
> maxdepth, gasmixes, tank pressures, etc.
> 

Yeah, I also wanted to add OTU but, I guess it is better to let it be
calculated by subsurface. But for now, if I'm not mistaken, it is not
taking into account the recovery during the surface interval.


-- 
Alexandre Belloni


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