[Arm-netbook] EOMA-68 passthrough implementation

[Derek LaHousse]

> 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.
> 
> >  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.
> 

I'm a little confused by the audio direction.  A pass-through card
should be receiving video signals on the "external" side of the EOMA
card, and providing data to the PCMCIA side.  To pass the audio, it
would need to break the signal out of the HDMI and then drive a USB
sound card, right?
 
> I'll need to figure out whether the ethernet connector requires
> integrated magnetics - I'll figure all that eventually.

I believe you should just be extending the wires from the EOMA input,
through the PCMCIA, to the Ethernet port on the other side of the
motherboard.  Are the magnetics to block cross-talk on a long length on
non-twisted pairs?

It's also important to pass the I2C through to the front of the EOMA
passthrough.  A system emulating the EOMA would need to be able to read
the EEPROM on the motherboard, as part of the spec.

ManoftheSea
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part
Url : http://lists.phcomp.co.uk/pipermail/arm-netbook/attachments/20120709/983d9335/attachment.bin