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.
Keep track of the gas mix type, and whether the gas mix is enabled or
not. Right now this extra information isn't really used for anything
yet, but it's available for future use.
The index in the gas change event should refer to the one of the fixed
gas mixes. All gas mixes with a higher index are either manual or
bailout gas mixes, and are reported with different events containing an
O2 and He percentages instead.
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.
The new Excursion v6 firmware supports some new commands for accessing
the dive index, and also uses a completely new data format. To preserve
backwards compatibility in the download logic to some extent, some
critical fields such as the profile length, remain stored at identical
offsets.
The new data format now contains a version field to allow for future
modifications. This version field is located at byte offset 3, which
corresponds to the highest byte of the 32 bit dive number in the old
format. Thus, unless someone manages to reach 16M dives, this field will
always be zero for the old format.
Co-authored-by: Ryan Gardner <ryebrye@gmail.com>
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.
The Oceans S1 uses a plaintext and line based communication protocol
over BLE. The larger payloads, which also contain plaintext data, are
transferred using the XMODEM-CRC protocol.
Based-on-code-by: Linus Torvalds <torvalds@linux-foundation.org>
The Deepblu Cosmiq+ uses a plaintext and line based communication
protocol over BLE, where the binary payload data is encoded as
hexadecimal characters.
Based-on-code-by: Linus Torvalds <torvalds@linux-foundation.org>
There are functions for reading 8, 16, 24 and 32-bit big and little
endian values, but the corresponding functions for writing such values
are not always available. The 64-bit variants are also missing.
Moving the implementation of the snprintf wrapper functions to the
platform module allows to re-use the same implementation throughout the
entire codebase.
The Oceanic Pro Plus 4 appears to "disconnect" somehow after about 30
seconds. The BLE connection remains up, but the dive computer simply
stops responding to commands. The download fails with a timeout error,
and the end-user can only download a few dives at most.
The Android DiverLog+ application appears to keep the connection alive
by re-sending the version and handshake commands once in a while. Copy
this behaviour by repeating those two commands every 50 read requests.
During testing, that's approximately every 25 seconds.
Note that both commands are required, sending only one of them does not
fix the problem.
The Oceanic Pro Plus 4 appears to support the big page B4 and B8 read
commands, but with some strange twists:
* When sending the B8 read command, a 256 byte packet is received. The
checksums of the packet are valid, but the upper half of the payload
data is always filled with zero bytes. That means we can't use this
command.
* The B4 read command appears to use a 2 byte checksum instead of the
normal 1 byte checksum. That means we can use this command with a
small model specific tweak.
The model number is now also available in the common struct. There is no
need to store it twice. The auto-detected model number from the version
table is also more reliable than the one passed by the caller.
With the model number in the version table, the version string can be
mapped to the corresponding model number. This allows to implement some
model specific behaviour already before being able to read the model
number.
In most cases, there is a simple one to one relationship between the
version string and the model number, but there are also a few
exceptions:
* For the Sherwood Wisdom 2 and 3, and the Beuchat Mundial 2 and 3,
each variant has a different model number, but the first part of the
version string is identical. The difference is in the firmware
version part. Handling this correctly requires two entries in the
table.
* For the Oceanic OC1 there are 3 different model numbers, and only 2
different version strings. That means there is no correct mapping
possible.
Some iX3M models support a dual mode Buhlmann and VPM decompression
algorithm. Currently libdivecomputer is only capable of reporting one of
those two algorithms, but that's still better than returning an error.
When no dives are present, the maximum value for the progress events is
set to zero, which triggers an assert. Fixed by letting the progress
events reach 100% instead.
In the latest G2 firmware v2.0, the size of the BLE packets increased to
101 bytes (with a one byte header and 100 bytes of actual payload). This
caused the download to fail, because the internal buffer was suddenly
too small for those larger packets.
These larger packets are most likely due to an update in the BLE stack
of the dive computer. Originally, the maximum BLE packet size was just
20 bytes (excluding the 4 byte L2CAP header and 3 bytes GATT header),
but BLE 4.2 increased the maximum packet size to 244 bytes (or 251 bytes
with the headers).
The USB HID code path keeps using the same fixed size packets as before.
The first byte of the BLE packets does no longer contain the size of the
payload. Since BLE supports variable sized packets, we can simply ignore
this byte and obtain the payload size from the BLE packet size.
The bookmark value is a bitfield indicating the type of bookmark:
1 - Pressed the bookmark button during a dive
2 - Reset the stopwatch
4 - Unknown
8 - Unknown
The hidapi based implementation returns as soon as the first packet is
received, while the libusb based implementation tries to read the
requested number of bytes. That fails with a timeout if the requested
number of bytes is larger than the size of a single packet and no
further packets are received.
Avoid this problem by limiting the size to the maximum packet size.
At the moment, trying to download an old dive for which the profile data
has already been overwritten with newer data fails. This used to work
fine, but around hwOS firmware v3.10, the behaviour described in commit
76187c550a806fe422920eb8795fa687244513f1 changed.
When downloading the compact/full headers, the firmware always sends the
headers without inspecting their content. Next, libdivecomputer uses the
length field in these headers to determine how many bytes to expect when
downloading the dive. However, when downloading the entire dive, the
hwOS firmware now checks whether the profile data of the dive is still
available. If that's no longer the case, the firmware sends a modified
dive header (with the begin/end pointer fields reset to zero, and the
length field reduced to 8 bytes), along with an empty dive profile.
Since libdivecomputer expects to receive the full profile as indicated
in the original header, the download fails with a timeout.
To workaround this problem, download the dive data in two steps. First,
download the 256 byte header and check whether it has been modified. If
that's the case, reduce the length to that of the 5 byte empty profile.
The header check is also updated to exclude the modified fields. For the
progress events, just pretend the full profile has been downloaded.
Not only the two byte end-of-profile marker 0xFDFD is a valid empty dive
profile, but also a profile with the length field present and set to 8
bytes. In that case the actual length will be just 5 bytes.
When downloading the compact headers (which is the default for recent
hwOS firmware), it's not possible to compare the entire dive header, but
we can at least the check the fields that are available.
Also return an error if the verification fails.
The Aqualung i770R appears to have 6M instead of 4M (high) memory.
Confirmed by trying to read past the 6M limit, which fails with a NAK
response. This amount also matches with the capacity stated in the
manual (6553 hours of profile data at a 60 second sample rate).
The memcpy and related functions expects a valid pointer, even if the
size is zero. Most libc implementations will handle a NULL pointer just
fine, but that's not guaranteed.
Simply skip the call when there is nothing to copy.
The maximum depth value is stored in the dive header. There is no need
to parse the profile data to obtain it. This also avoids returning a
zero depth when the profile data is no longer available.
A few other fields (e.g. average depth, atmospheric pressure and
temperature) are also present in the dive header.
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).
