Although the communication protocol of the OSTC3 is nearly identical to
that of the Frog, the different size parameters make it hard to share
the code easily. On top of that, if we ever implement native bluetooth
communication support, we'll need a completely separate backend anyway.
Therefore the Frog backend is simply duplicated, with a few OSTC3
specific changes applied here and there.
The existing ostc parser is upgraded to support the new OSTC3 data
format.
The Petrel (with updated firmware) supports an enhanced communication
protocol, which is more efficient and powerfull than the legacy Predator
compatibility mode. The new protocol uses data compression for faster
transfers and supports the ability to selectively download individual
dives. Last but not least, the new protocol isn't limited to the last
128kB of logbook data, but can access the full logbook capacity (16MB).
This is only a preliminary version. There is certainly some room for
improvement, but the basic functionality is already in place. That
should be sufficient for daily use, and possibles issues can always be
fixed when discovered.