Any brave dive computer download testers out there?

[Sébastien Dugué]

On Thu, Apr 19, 2018 at 1:18 AM, Linus Torvalds
<torvalds at linux-foundation.org> wrote:
>
> Hmm. Which IRDA chip is it that is in the Uwatec dongle?
>
> Is it perhaps the MosChip MCS7780? You'd know, because then it would
> be using USB ID 9710:7780. That seems to be the common case.

  Yep, as Willem pointed out, this is the one used in the overpriced Uwated
adapter.

  I personally use a STIR4200 and it looks pretty straightforward too.

>
> You can find datasheets for it by just googling for
>
>     MCS7780 Datasheet type:pdf
>
> and from a quick look, the setup looks pretty simple. It has various
> configuration bits, but it looks like the control register defaults to
> al the normal bits, so you may not even need to touch it.
>
> For example, it seems to default to 9600 baud, all automatic defaults
> for SIR. Maybe I missed some bit, but it basically seems to default to
> "ready to simply be used".
>
> So you might be able to just set up plain USB bulk transfers to send
> and receive the data. *Maybe* you need some setup, but it's not clear
> that you do.

  Yes, we propably need to add framing (at least the stir4200 needs it),
plus talking the right irda protocol and add discovery and it should be OK.

>
> So accessing this thing with libusb looks fairly straightforward, if
> you already have packet traces and know what the wrapping is (I think
> the MCS7780 just wants to add a 2-byte little-endian packet length to
> the data, but then whatever the IRDA address encapsulation etc is I
> have no idea).

  That's the hard part, faking and irda stack that is able to talk to the stacks
implemented in all those irda DCs.

  Sadly, I could not get my hands back on those traces. I'll have to
search some more...

  Sébastien.