[Arm-netbook] EOMA-68 passthrough implementation

[lkcl luke]

On Mon, Jul 9, 2012 at 6:41 PM, Ryan Mullen <rmmullen at gmail.com> wrote:
> Hi,
>
> On Mon, Jul 9, 2012 at 1:06 PM, lkcl luke <luke.leighton at gmail.com> wrote:
>>  that would be absolutely brilliant.  if you use kicad then i would
>> also potentially be able to help, as i'm sure would a few others.
>
> I would be using kicad, so that is good. I have more experience with
> PADS than with kicad, but I've done one small project with kicad and
> it went well.

 cool.

 well, if you've used fped (which i recommend) i've just added a
TQFP-100 for you, to match the TFP401a.  you might want to check it
though.  i based it on the kicad-libs "qfn.fpd" because qfn.fpd in
kicad-libs has a central earth/heatsink pad, whereas the qfp.fpd file
didn't.  and it had better arrows (in green).

 http://git.hands.com/?p=eoma.git;a=tree;f=pcb/passthrough/modules;hb=HEAD

 if you install fped and run make in that directory you'll get a kicad mod file.


>> also then you could use the libraries i've already done at
>> git.rhombus-tech.net.  if you like, email phil at hands.com directly and
>> ask him if you could be added to that repository ok, with an
>> explanation as to why you need access to the eoma.git repository.  to
>> be absolutely clear and unambiguous: the url is:
>>
>>    url = git+ssh://git@git.rhombus-tech.net/eoma.git
>
> I'll follow up with phil when I'm ready to begin and after I've
> familiarized myself with your git repo. Thank you for the info.

 no problem.  btw the general rule is: source only.  under no
circumstances add anything that can be generated from a command, even
if the output is a human-readable text file.  so example: under no
cirmstances add tqfp100.mod if it is auto-generated by the Makefile
from tqfp100.fpd using the "fped" command.


>>  would anybody like to help finding the required mid-mount HDMI and
>> USB-OTG sockets?  ryan, are you considering doing an audio IC of some
>> description on the pass-through card, or just leaving that for now?
>> (can always do a revision 2.0).
>
> I was planning just to use standard connectors for the signals that
> are clearly ethernet, or SATA, etc. For all the GPIO/I2C pins I'd
> probably use 0.100"-center plated holes and let the user solder
> something.
>
> If there were an IC that could pull the audio out of the HDMI signal
> and put it on a headphone jack, I might be interested in using it.
> However, I don't plan on getting too fancy, and if it bloats the cost
> much, I would hesitate.

 yeah not worth worrying about first.

> I'll need to figure out whether the ethernet connector requires
> integrated magnetics - I'll figure all that eventually.

 ack:)

>>  btw there is some innnsaaane costly requirement for HDMI's HDCP - you
>> might like to consider instead just having a DVI-to-RGB/TTL converter,
>> like the TFP401a... oh, that's exactly the IC i put on the diagram
>> anyway ha ha :)
>
> I don't know the details of HDCP or its requirements, but if that IC
> is sufficient, then I don't see why I should look elsewhere.

 yeahh... it starts to get complicated.  don't need that.

> Anyway, I'm not a corporate entity and I want to say up front that I'm
> interested in this project for purely hobbyist reasons. Therefore, if
> you have deadlines, customer demos, conventions, or support worries,
> then please do not rely on me to deliver anything at all - the usual
> disclaimers apply.

 yeah i have no problem with that.

 /peace.

 l.