Returning disabled gas mixes to the application mainly results in lots
of unnecessary information. Therefore, remove all disabled gas mixes,
unless they are actively used. Many other dive computers do not even
include disabled gas mixes in the data.
Unlike previously assumed, the on/off state of each gas mix is actually
available in the PNF data format (opening record 4). For the older
Predator data format, this info isn't available and all gas mixes are
manually marked as enabled.
For dives in HP CCR mode, the oxygen and diluent tanks are stored at a
fixed index. This information is more reliable than using the tank name,
and also prevents the incorrect labeling of one of the other tanks as an
oxygen or diluent tank.
Firmware v84 introduced support for sidemount diving. Users can now
configure the two sidemount tanks as the source for the GTR (Gas Time
Remaining) estimations. We can take advantage of this feature to detect
the sidemount tanks. This is more reliable than using the tank name.
For open-circuit dives, the oxygen and diluent usage doesn't make any
sense at all. But when an open-circuit diver uses the letter 'D' to
indicate a tank for decompression use, it will get incorrectly labeled
as a diluent tank.
Fixed by restricting the oxygen/diluent usage to CCR dives only.
For open-circuit dives it makes no sense to also include the configured
diluents. Usually those diluents are only present because the diver uses
the same dive computer for both open and closed circuit dives.
The dc_parser_set_data() function allows to re-use a parser object for
multiple dives. The advantages of this feature are actually very limited
in practice. The reduction in memory consumption is almost negligible,
because the amount of internal state in the parser is typically very
small. But the implementation requires some additional complexity
because each backend needs code to reset its internal state. Therefore,
the function is removed and the data and size needs to be passed
directly to the dc_parser_new() and dc_parser_new2() functions instead.
Because keeping a reference to the data has also caused issues in the
past, especially for applications implemented in a garbage collected
language, the data will now also get copied internally.
Because the sample struct is passed by value, the size of the structure
can't be changed without also changing the function signature and
breaking backwards compatibility. This prevents adding new fields in the
future, to support some new features.
When passing the sample struct by reference using a pointer, the size of
the pointer does always remains the same.
For gas consumption calculations it's very convenient to know whether a
tank is used for example in a sidemount configuration, or as
oxygen/diluent tank on a rebreather.
For rebreather dives, it's convenient to know whether a gas mix is used
as a closed-circuit mix (oxygen/diluent) or as an open circuit mix
(bailout).
Some dive computers report the time of the next decompression stop,
while others report the Time To Surface (TTS). Some models can even
report both.
Add a TTS field to the deco sample to support both values.
Rebreathers typically support multiple ppO2 sensors as a safety measure
in case a sensor fails during the dive. The current api can already
report multiple ppO2 values per sample, but it does not provide any
information about which sensor the measurement is from.
The new sensor index provides this info, and can also be used to
distinguish between the average/voted ppO2 value using the special value
DC_SENSOR_NONE.
After the previous commit changed the resolution of the sample time to
milliseconds, the dive computers which actually support a higher
resoltion can now enable this feature and report all samples.
Some dive computers, especially freediving computers, supports multiple
samples per second. Since our smallest unit of time is one second, we
can't represent this, and the extra samples are dropped. Therefore, the
units are changed to milliseconds to prepare supporting this extra
resolution.
The OSTC stores either the OC gas mixes or the CCR diluents depending on
the dive mode. For CCR dives, there is also bailout to an OC gas
possible, and those gas mixes are added dynamically to the manual gas
mixes.
The Shearwater dive computers store both the configured OC gas mixes and
CCR diluents in the header.
In both cases, the gas change events should reference the correct type
of gas mix. This patch takes care of that.
Dives without a valid gas mix in the sample data (e.g. both the O2 and
He set to zero) are currently ignored by accident. Because the
o2_previous and he_previous variables were initialized to zero, those
invalid gas mixes were not processed.
Add an explicit check for such gas mixes to make this more obvious.
For freedives it makes no sense to report any gas mixes. The freedives
also use a different sample format, which doesn't generate any gas
change events.
Especially among technical divers, it's not uncommon to carry spare
tanks that will only be used in emergency situations (for example a
rebreather with one or more bailout tanks). Since those gas mixes are
not used throughout the dive, they were also not reported to the
application.
Fixed by reporting all configured gas mixes. Applications can still
obtain the previous result after manually inspecting the gas switch
events in the samples and filtering out the unused gas mixes.
This partially reverts commit c8b166dadbf961e17a9bd1cc28db3d92832ddf72.
For the HP CCR mode, the O2 and diluent tank pressure was stored in the
T1 and T2 tank pressure fields. Starting from log version 14 they moved
to dedicated fields in the EXT sample, next to the T3 and T4 tank
pressure. Thus the maximum number of tanks increased from 4 to 6.
For dive computers where the reference time (epoch) of the device is
unknown, libdivecomputer uses the current time of the device (devtime)
and the host system (systime) to synchronize both clocks.
Currently, both timestamps are passed directly to the constructor of the
parser. With the new public function, the application can adjust the
timestamps afterwards.
Some dive computers store the depth as an absolute pressure value (in
bar). To convert to a depth value (in meters), the atmospheric pressure
and water density are required. For dive computers that do not have
those values available, libdivecomputer uses a default value. With the
new public api functions, applications can adjust those default values.
Some dive computers already provided a backend specific calibration
function. Those functions are now deprecated. They are kept around to
maintain backwards compatibility for now, but they will be removed in
the next version.
Report the decompression algorithm (Buhlmann, VPM, RGBM or DCIEM), and
if available also the parameters. For now only the conservatism setting
is supported, and for the Buhlmann algorithm also the Gradient Factors
(GF).
The latest firmware does store some additional information for each
tank. Right now it's not really used for anything yet, but it's
available for future use.
In the older Predator-like data format, the 4th opening/closing record
is the last one. To avoid accidental use of the higher ones, leave them
undefined.
During the download, the model number is obtained from the hardware type
because the model number isn't available before downloading the first
dive. Since the list with available hardware types is incomplete, the
correct model number is not always available. However, during parsing
the correct model number is available in the final block.
Starting with log version 8, the dive mode is stored in one of the
opening records. For backwards compatibility with older firmware
versions, the autodetection based on the status field in the sample data
is kept as a fallback mechanism.
The difference between two unsigned integers can be negative. To avoid
ending up with some very large positive values, an explicit cast to a
signed integer is required.
Depths are normally expected to be always positive, but near the surface
the pressure will be very close to the atmospheric pressure. Therefore
small negative values are not unusual.
At some point (possibly around v71 of their firmware), Shearwater implemented
PNF for the Petrel and Petrel 2. Those are of course not air integrated, and
apparently don't support adjustable sample rate, so the log data doesn't include
opening and closing record 5. Instead of failing when those aren't found, we
should simply only access those when they actually exist.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Some of the newer Shearwater dive computers support up to 2 tank
pressure sensors. The tank pressure samples were already reported, but
the tank field with the corresponding begin/end pressure was still
missing.
To be able to collect the tank begin/end pressure, the log version needs
to be available earlier, because it's needed for parsing the tank
pressure data in the samples. Therefore, extract the log version
immediately after locating the opening record.
This will allow parsing dives from the Shearwater Teric, but depending on the
firmware could also be used on older models.
Based on ideas and code from Dirk Hohndel
The warning about disabling the O2 sensors due to factory default
calibration values, applies only if there is at least one calibrated O2
sensor present.
This has no effect on the calibration bits, because those are already
zero if there are no calibrated O2 sensors present.
If all (calibrated) sensors still have their factory default calibration
values (2100), they are probably not calibrated properly. To avoid
returning incorrect ppO2 values to the application, they are manually
disabled (e.g. marked as uncalibrated).
Add a new type to distinguish between closed circuit (CCR) and
semi-closed circuit (SCR) diving. Some dive computers from HW and
DiveSystem/Ratio support this.
Because the CCR/SCR abbreviations are more commonly used, let's take the
opportunity to also rename the existing DC_DIVEMODE_CC. To preserve
backwards compatibility, a macro is added to map the old name to the new
one.
Reported-by: Jan Mulder <jlmulder@xs4all.nl>
The first dive computer to support this is the Perdix AI. Interestingly,
this keeps track of two sensors at all times. I haven't seen data with
two sensors active, yet.
[Jef Driesen: Update to the latest documentation.]
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The earliest document I have references log version 6. There are
apparently older versions, but I don't know what the differences
are. Before version 7, the log version wasn't always reliably
stored, so we assume 6 is the minimum and use 7 (or later) if we
find it.
[Jef Driesen: Initialize and reset the cache correctly.]
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Allthough most dive computers always use local time and don't support
timezones at all, there are a few exceptions. There are two different
sources of timezone information:
- Some of the newer Uwatec/Scubapro devices use UTC internally and also
support a timezone setting. This UTC offset is currently taken into
account to obtain the dive date/time, but the UTC offset itself is
lost.
- Uwatec/Scubapro and Reefnet devices rely on the clock of the host
system to synchronize the internal device clock and calculate the
dive date/time. The consequence is that the resulting date/time is
always in the timezone of the host system.
In order to preserve this timezone information, the dc_datetime_t
structure is extended with a new "timezone" field, containing the UTC
offset in seconds. Devices without timezone support will set the field
to the special value DC_TIMEZONE_NONE.
The dc_datetime_localtime() and dc_datetime_gmtime() functions will
automatically populate the new field with respectively the local
timezone offset and zero. The dc_datetime_mktime() function will take
into account the new timezone field for the conversion to UTC. The
special value DC_TIMEZONE_NONE is interpreted as zero.
The O2 sensor millivolt values are only valid if external O2 sensor
monitoring is enabled.
Note that the interpretation of the PPO2 status bit appears to be
reversed (0=external and 1=internal).
Reviewed-by: Anton Lundin <glance@acc.umu.se>
Correcting the Predator calibration value with a scaling factor produces
even more reasonable ppO2 values compared to using a constant offset.
The scaling factor of 2.2 is based on a linear regression between the
average ppO2 reported by the dive computer, and the average ppO2
calculated over all (calibrated) sensors using the raw calibration
value.
Reviewed-by: Anton Lundin <glance@acc.umu.se>
The calibration values for the Petrel are typically in the range 1600 to
2400, while for Predator they are much smaller, with values in the range
800 to 1400. The consequence is that the calculated ppO2 values are too
low for the Predator. Adding a constant offset of about 1000 changes the
calibration value to be in approximately the same range as the Petrel,
and hence more reasonable ppO2 values. But this correction should only
be applied for the Predator, and not the Petrel.
Reviewed-by: Anton Lundin <glance@acc.umu.se>
This reads the reported mV values from the sensors, and based on the
calibration values converts it into a ppo2 value to report.
Signed-off-by: Anton Lundin <glance@acc.umu.se>
