As the name already indicates, a device descriptor is lightweight
object which describes a single device. Currently, the api supports
getting the device name (vendor and product) and model number. But
this can extended with other features when necessary.
Adding the "dc_" namespace prefix (which is of course an abbreviation
for libdivecomputer) should avoid conflicts with other libraries. For
the time being, only the high-level device and parser layers are
changed.
Note that this implementation will fail if the ringbuffer doesn't start
at the fixed address 0xA000. This is very likely to occur once the
ringbuffer is filled completely and the device starts to overwrite old
data.
To be able to cancel an operation, an application should register a
callback function that returns a non-zero value whenever the active
operaton should be cancelled. A backend can invoke this callback function
to query the application for a pending cancellation request.
The handshake function is now called internally (even if it doesn't seem
to be required at all), and the version function can be called through
the public api. The format of the version data is changed too.
The memory layout of the Mares Puck and Nemo devices is very similar,
which allows to share the parsing code between the backends.
The Mares Puck protocol allows for a more efficient implementation, by
reading only the data that we really need. But as an intermediate
solution, reusing the Nemo code is good enough.
Although calibration is optional, it's highly recommended because it
reduces the transfer time considerably. The calibrate function is
removed from the public api.
When the IRDA backend is disabled or not supported by the underlying
platform (such as on Mac OS X), the Uwatec Smart parser is disabled as
well. The symbols file is updated to reflect this.
