Partial push of Josh's configure-dive-computer GSoC project

Jef Driesen jef at
Wed Aug 20 00:58:58 PDT 2014

On 2014-08-19 19:12, Davide DB wrote:
> 2014-08-19 16:48 GMT+02:00 Jef Driesen <jef at>:
>> On 2014-08-19 15:20, Davide DB wrote:
>>> Months ago, when i started to use Subsurface, I asked to support 
>>> Sensus
>>> ultra devices. I helped Miika to understand their CVS format. Miika
>>> implemented only the CSV import via their file. So the device must be
>>> downloaded via their client.
>> That's not true. The Sensus Ultra is a supported devices. You can 
>> download
>> your dives directly from subsurface. Have you actually tried this
> This is my request in January:
> There was a mail exchange with Miika. I gave my support on csv format 
> and
> this end up in this patch that I tried several times:

These discussion were about importing data from the Sensus Manager 
application, not direct downloading from the Sensus Ultra. That are two 
completely different things.

> I could not find a patch showing Subsurface downloading directly the 
> Sensus
> Ultra. I searched trough my archives and I found only references to CSV
> import.

You won't find any patches for direct download, because you don't need 
any. Downloading from the Sensus Ultra has been supported since one of 
the very first subsurface releases.

>> So you are blaming Reefnet for problems with the Prolific drivers? 
>> There
>> is very little they can do about that, because the driver is made by
>> Prolific, not Reefnet.
>> I guess many of those Prolific driver problems are due to the fact 
>> that
>> their Windows driver started to blacklist counterfeit chips a few 
>> years ago:
>> Those "chinese" counterfeit chips are probably widespread in existing
>> hardware :-(
> Jef, don't misunderstand me. I'm not criticizing your work or the other
> Subsurface guys but I'm a final customer which paid a product for 100%
> functionality and I blame Reefnet because I paid them not Prolific and 
> to
> log my dives I do not want to know about who wrote what. I paid 
> reefnet. So
> I do not blame the programmer who wrote that data logger.
> Just to be clear: If I buy a Wolkswagen Golf and after two years I 
> cannot
> start my car, I blame Wolkswagen, not Bosh who built the starter motor. 
> Or
> maybe SaintGobain for the VW Golf glasses.

In your car analogy, if Volkswagen gets many complaints about that Bosh 
start motor, then no doubt they will forward the complaint to Bosh. And 
they will hopefully fix the problem. But unlike Volkswagen, Reefnet is 
just a really tiny customer of Prolific. Most likely they don't even buy 
their usb-serial chips directly from Prolific. So any complaints on 
their side are likely going nowhere. Whether you like that or not, 
that's probably not to far from the truth...

>>  So IMHO, before spending time on a obsolete device, try to solve the
>>> download problem.
>> There is a long standing problem with libdivecomputer and the Sensus 
>> Ultra
>> on Mac OS X (seems to be a timing or latency issue). But on my Linux 
>> system
>> it's rock solid. I have to admit I haven't tested on Windows in a long
>> while (it's not my primary OS).
>> At the time of its introduction, which is more than 10 years ago, a 
>> dive
>> computer with a PC interface was pretty rare. Nowadays, you may no 
>> longer
>> need one, because even the cheapest dive computer model has it. But 
>> even by
>> todays standards, the Sensus Ultra design isn't outdated. For example 
>> the
>> memory capacity (2MB) and precision/accuracy still exceeds that of 
>> many
>> current dive computers. Compare that with Suunto (8-64K), Oceanic 
>> (32-128K)
>> or Mares (16-1024K) just to name a few. Only state of the art 
>> technical
>> dive computer like the OSTC and Petrel have comparable (or more) 
>> logbook
>> memory.
> Very nice but a Sensus costs 250$, more or less like an XDeep Black BT.
> Right now I buy a Sensus Ultra jsut to discover that I cannot see the 
> device on my Windows pc. What's the solution? Using XP? Blaming 
> Prolific?
> BTW I used to be an assembler programmer until nineties so I fully
> understand what you mean but I'm tired to pay cash for things that not 
> work.
> My opinion (again as simple final user) is that first of all must be
> resolved the low lever interface problem (aka prolific drivers) to
> resurrect this little nice device.
> I tried everything on 6 different Win7 machine at my job place. I
> downloaded all the existent prolific driver versions with no luck. I 
> ended
> up working with a XP VM.
> A frind of mine with a macbook had the same fate. Once update to the 
> latest
> OS incarnation, no way to see the USB device.
> I even have two different kind of hardware interfaces (one naked and
> another one smaller with a plastic box) but they have the same 
> chipsets.
> They should be somewhere in the basement.

Don't get me wrong, I can certainly understand your frustration, but 
there is always another side of the story too. The majority of the 
support issues I deal with for libdivecomputer, turns out to be user 
mistakes (e.g. no or wrong driver installed, wrong type of cable, wrong 
type of dive computer selected, forgot to activate PC mode, nearly empty 
batteries, etc). So that's nearly always my first assumption. Note that 
I'm not saying this is also the case for you.

Anyway, there are so many different systems out there (3 major operating 
systems, each with different versions, different hardware 
configurations) and different level of expertise of end-users. That 
makes it impossible to guarantee that everything will always work on 
every system. I wish I could do something about it, but unfortunately 
the low-level driver related stuff is something I have no control over.

Just to give you an example of how bad things can be, take a look at the 
procedure to install the driver for Seiko based devices (Cressi, Zeagle, 
etc), which requires patching the Prolific driver:

I'm not even sure this even works on newer Windows version (7 and 8). 
But those users have no alternative, because Seiko has simply exited the 
dive computer business!


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