With the new APOS4 firmware, the latest ix3m and idive models support a
wireless tank sensor. For dives without a tank pressure sensor, the
pressure field in the sample is zero. Thus the first non-zero value
indicates the presence of a tank sensor.
The new APOS4 firmware changed the data format and communication
protocol. The size of the samples changed from 54 to 64 bytes, and in
order to speedup the download, a single data packet contains 3 samples
at once. If the number of samples is not an exact multiple of three, the
last packet appears to contain garbage data.
For parsing, the firmware version is available in the dive header.
Unfortunately it can't be used for dives that are downloaded from a
device with the new firmware, but which have been recorded with an older
firmware. Such dives store the old firmware version in the dive header,
but they also use the new sample format. As a workaround, we inspect the
size of the dive.
The second variant of the open or create functions were introduced to
maintain backwards compatibility. But after being removed from the
public api, these functions serve no purpose anymore, and can be removed
completely.
The vendor_product_parser_create() and vendor_product_device_open()
functions should be called indirectly, through the generic
dc_device_open() and dc_parser_new() functions. And the
vendor_product_extract_dives() functions are internal functions that
should never have been part of the public api in the first place.
The dive mode is stored in each sample, and can change during the dive.
In order to report a single value for the entire dive, we assume the
value of the first sample is representive for the entire dive. For
example a dive started as a CC dive but with a bailout to OC during the
dive, is still considered to be a CC dive.
A warning is generated if the dive mode changes.
Both the allocation and initialization of the object data structure is
now moved to a single function. The corresponding deallocation function
is intended to free objects that have been allocated, but are not fully
initialized yet. The public cleanup function shouldn't be used in such
case, because it may try to release resources that haven't been
initialized yet.
Instead of freeing the object data structure in the backend specific
cleanup function, the memory is now freed automatically in the base
class function. This reduces the amount of boilerplate code in the
backends. Backends that don't allocate any additional resources, do no
longer require a cleanup function at all.
The new gasmix sample contains the index of the active gas mix.
This new sample is intended as a replacement for the existing gas change
events (SAMPLE_EVENT_GASCHANGE and SAMPLE_EVENT_GASCHANGE2). To maintain
backwards compatibility, the legacy events are marked as deprecated but
not removed yet.
The protocol of the iX3M series is almost identical to the protocol of
the iDive series. The main difference is that the command bytes and the
size of the response packets have been changed. In order to be able to
communicate with the correct set of commands, the user needs to supply
the correct number now. To maintain backwards compatibility, a new
variant of the open function is added.
The size of the dive header is one byte smaller: 0x32 instead of 0x33
bytes. Because we were expecting a larger packet, this bug caused the
downloading of the dive headers to fail. I'm surprised no one noticed
this mistake before.
