Incorrect tank info.

Jef Driesen jefdriesen at
Thu Sep 20 15:04:09 PDT 2012

On 20-09-12 22:56, Dirk Hohndel wrote:
> Jef Driesen <jefdriesen at> writes:
>> On 24-08-12 11:03, Jef Driesen wrote:
>>> What exactly happens if you set the device to air mode? Can you still
>>> configure the gasmixes, or is access to the gasmix settings
>>> completely
>>> disabled? I'm just trying to understand the logic used by the device.
>>> Then we can fix the libdivecomputer code to match that logic.
>>> Based on the comments so far, this seems to be what is happening:
>>> if (air) {
>>>       Ignore the gasmix settings, and assume a single mix with air.
>>> The
>>> gasmix settings retain their previous (non-air) values only as a
>>> convenience, so you don't have to adjust the settings for your next
>>> nitrox and/or multigas dive, but they are not used.
>>> } else {
>>>       Use the gasmix settings.
>>> }
>> I would like to fix this issue before the 0.2.0 release. I have
>> attached a work-in-progress patch that needs some testing. I think it's
>> correct for the older generation models (Vyper 2, D9, etc), but I
>> suspect that for the newer models (Helo2, D4i, D6i, D9tx, etc) the gas
>> model byte is stored at a different offset.
>> Normally I can easily test this kind of stuff myself, but for some
>> reason the latest Suunto Dive Manager (SDM) doesn't accept arbitrary
>> serial ports anymore. I guess there is some kind of check for the USB
>> VID/PID, or the FTDI driver. I used to have a linux kernel module to
>> emulate an FTDI usb-serial chip (using the usb gadget interface), but it
>> doesn't compile anymore with recent kernels :-( So for now, I can't get
>> my test data into SDM to confirm the patch is correct, and thus I need
>> some testing with real hardware.
> There's this guy on this mailing list who might be able to help you with
> getting this to compile under the latest Linux kernel. Have you asked
> him for help? :-)

No, I didn't ask. But I'm sure he reads this :-)

I made some progress today. The virtual FTDI module compiles again, and I can 
even get the FTDI driver to recognize the virtual device, but I can't get any 
data passing through it.

Anyway, if anyone wants to have a look, the source code is located here:

The first one is the code that used to work (on kernel 2.6.X, where X was 
something like 39 I think). The second one is my current rewrite (using code 
from kernel 3.3.0).

> Also, Linus, you have a Vyper Air. Anyone else with Suuntu computers who
> could help test Jef's code?

I have an updated patch attached. For the older devices, I can still use an 
older version of SDM (2.x), and everything looks good for the few devices I 
tried. The newer devices (Helo2, D4i, D6i, D9tx) are the problematic ones 
because they are only supported with a recent version of SDM (3.x). As far as I 
can tell from just the parser output it looks okay, but I can't confirm with 
data from SDM.

I don't think the patch is any worse than the current code, so if necessary I 
can release it without testing. But being able to test is always better of course.

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