On 2018-04-19 09:42, Sébastien Dugué wrote:
On Thu, Apr 19, 2018 at 1:50 AM, Linus Torvalds
<[email protected]> wrote:
On Wed, Apr 18, 2018 at 4:18 PM, Linus Torvalds
<[email protected]> 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.
I discovered this a while ago:
https://github.com/Diveboard/DC-agent/tree/master/3d-party/irda_mac
It seems to be based on some minimal IrDA stack for micro-controllers:
http://web.archive.org/web/20061124205138/www.blaulogic.com/pico_irda.shtml
This is probably a good starting point!
Jef
_______________________________________________
subsurface mailing list
[email protected]
http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
