Any brave dive computer download testers out there?
sebastien.dugue.subsurface at gmail.com
Thu Apr 19 00:42:28 PDT 2018
On Thu, Apr 19, 2018 at 1:50 AM, Linus Torvalds
<torvalds at linux-foundation.org> wrote:
> On Wed, Apr 18, 2018 at 4:18 PM, 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.
> Hmm. Googling around, I see that it might also be the Sigmatel
> Stir4200 (USB ID 066F:4210).
> That actually has better documentation, and shows exactly the framing
> for the normal MIR format (which it would be for the normal 9600
> baud). I suspect the MCS7780 needs that same format, it's just not
> documented as well.
> The packet wrapping looks like this:
> 0x55 0xaa 2-byte LE length, 0xC0*n .. escaped data .. 2-byte LE CRC 0xc1
> and from what I can tell, the Stir4200 also resets to sane default
> values (9600 baud SIR).
> But you may have to do some USB control transfers to set the data
> direction. It *looks* like the MCS7780 is simpler and defaults to just
> "automatic data direction" (which presumably just means "send if there
> is TX data, receive otherwise").
Yes, but to me talking to the chip is the easy part. I'm more concerned
about implementing enough of the irda protocol stack to be able to talk
to all those embedded stacks.
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