Which protocol to implement on a home brewed diving computer ?

[Thomas Schrein]

Hi list,

me and some friends are developing a DIY diving computer at the moment.

See link (only in German at the moment):
http://www.skin-diver.org/sdiv/bastelecke/odico/

We intent to have it as a hardware platform for open source diving 
software development. We are thinking to have it available as a kit in a 
few month.
The software is in a alpha status, using Bühlmann ZHL16 Deco.
Odico uses a CORTEX M4 processor and can be programmed/debugged from 
outside with CooCox.
We have made about 10 dives with hardware release OH0.1, deepest 
47m/150ft. It's works fine, very reliable :-)

USB virtual com port is used for the communication with a PC.
"subsurface-divelog" seems to be good software/project for a Pc front 
end and we would like to use it for odico.
So next is to implement a protocol into odico, compatible with 
"subsurface-divelog".

So we have some questions:
Which protocol do you recommend us to implement into odico ?
One idea is UDDF/UDCF, is this a good approach ?
I also found some specs for the Suunto protocol and OSTC; is it better 
to implement this ?
Other suggestions ?

I am very keen about your comments.

Thanx
Thomas Schrein