help needed: Android devices and FTDI dive computers

[Dirk Hohndel]

On Wed, Aug 08, 2018 at 12:00:50PM -0700, Linus Torvalds wrote:
> On Wed, Aug 8, 2018 at 11:50 AM Dirk Hohndel <dirk at hohndel.org> wrote:
> >
> > Since you have at least one of those cables, would you mind installing the
> > app and sending me the output? Just so I know which information I can get
> > from an official Suunto cable?
> 
> I tried to, but I have once more completely mis-placed my USB-C to A cable.
> 
> I have at least four of those things lying around, since we have three
> Pixel's in the household and I'm pretty sure they all came with one.
> And _last_ time I couldn't find it I ordered one off Amazon.
> 
> They are small and I never use them.
> 
> I'll try to look around some more.
> 
> NOTE! You can *not* rely on whatever product name strings that you get
> from various apps. They do not come from the device itself, they come
> from a database lookup of the vendor/device ID numbers. And even if
> that database is in some system library, it doesn't mean that every
> Android device will have the _same_ database.

I believe that to be wrong. As you see in the screenshot posted here,
there's a name from a database, and a name as reported from the device.
Clearly the name "Smartinterface" is not what came from some database for
Vendor ID 0403 - as that is FTDI.

> So for all I know, you might literally get two different names for the
> same device on two different phones, just because they have different
> Android versions on them.

You might be right. I need to spend more time reading the specs to
understand how much of this comes from the USB spec vs interpretation in
Android.

> So you really should only trust the numerical vendor/device ID. That's
> what the actual USB device will report.

See above. Wouldn't be the first time I'm wrong, won't be the last.

/D