deco rewrite [was Re: Meaning of GF settings]

Robert C. Helling helling at
Tue Jan 8 13:40:38 PST 2013

On Jan 8, 2013, at 6:37 PM, Dirk Hohndel wrote:


> I just pushed out a commit with the following commit message. Please
> take a quick look to make sure that you are ok with the changes to the
> comments at the top of the file and that I didn't mess anything up with
> the one actual change that I made (described in the last paragraph of
> the commit message).

looks good. You did set buehlmann_config.last_deco_stop_in_mtr back to 3 (I had set it to 0 as this looks nice for smooth==TRUE). Was that on purpose?

Two more questions: I kept the convention of using doubles and units of meters and bars rather than integers and mbar and mm and only change back to those in deco_allowed_depth as otherwise those Buehlmann constants that are dimension-full would have to be changed as well and I would be a bit worried that the increments in add_segment might be small compared to 1mbar. I hope this is ok. Was my assumption correct that even when set to imperial units subsurface internally works with SI units since otherwise we would need imperial units for those constants as well?

You say the first version of deco.c was based on code by Matthias Heinrichs. I had a brief look at the OSTC firmware but I could not recognize any code fragment. Do you know if he uses that code or similar for his dive computers in any way? If he does I would let him know that I believe that code has problems.


Robert C. Helling     Elite Master Course Theoretical and Mathematical Physics  
                      Scientific Coordinator                                   
                      Ludwig Maximilians Universitaet Muenchen, Dept. Physik    
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