[PATCH] Visualisation of individual oxygen sensor data for CCR dives

[Willem Ferguson]

Currently Subsurface only explicitly accommodates the Poseidon MKVI and 
the APD Inspiration family of rebreathers, having two/three oxygen 
sensors by default. The reason is simply: these are the equipment mostly 
used by local divers here. Since rebreathers often download only one 
dive at a time (one dive = one complete dive log file), a normal dive 
list-oriented download is not relevant. There is not the equivalent of a 
libdivecomputer for these CCR uploads and we import the MKVI and APD 
dives through the text file import mechanism. Currently, several third 
party manufacturers use Shearwater equipment as the controllers for CCR 
equipment (e.g. Hollis Prism). The addition of Shearwater-generated CCR 
imports will be the next quantum step for making Subsurface accessible 
to CCR divers. There are some problems with respect to the import of CCR 
dives:

1) Since there is not the equivalent of a libdivecomputer, we are 
dependent on doing the inital download from CCR to text file using 
proprietary software that comes with the equipment (mostly Win-only). 
Extremely inconvenient. Then import from text to Subsurface.

2) I do not know how many Subsurface users actually log CCR dives. I 
know of four users in our country. Clearly a pretty small user base. 
There has been no correspondence from CCR divers on the mail list, so we 
do not know in which ways to improve the existing code.

There is a possibility that the extension to Shearwater may be very 
simple, depending on whether Jeff includes sensor data in 
libdivecomputer, otherwise it may be a bit more complex.

Kind regards,
willem