[Tfug] Tablets

[Bexley Hall]

Hi Zack,

--- On Sun, 8/26/12, Zack Breckenridge <zbrdge at gmail.com> wrote:

> Your requirements make this sound like a "roll your own," project to me:

I'm hoping that's not the case.  The "hallway" device (that I *must*
design) can afford to be a bit less "stylish" (cosmetically) as a
consequence of its extra size, etc.  The other units *really* want
to look very "commercial".

> Since you need a tablet you can root. You can find a good
> list on cyanogenmod.com, but then
> you might have to run cyanogenmod and that might not be what
> you're looking for.

I took a peek at the site and it seems like that would, indeed, be
the case.  I'd be trading one (lame) OS for another (actually, pretty
much the *same*!).

> Ubuntu for tablets might be a better
> way to go: http://www.omgubuntu.co.uk/2012/06/ubuntu-12-04-firmware-released-for-smartq-t20-tablet

This is more promising!  However, I have been unable to find the
sources (required by GPL) available, anywhere.  Relying *exclusively*
on a Chinese vendor to provide stable and reliable support (when they
can't even provide English documentation!) seems a bit too risky.
Show me the sources and I can support it, without having to rely on
someone with an unknown commitment to that effort.  <frown>

> I doubt any device listed there or the smartq tablet has
> wired Ethernet, so yes you'd probably have to use USB to
> Ethernet.

I haven't looked through all the SmartQ offerings.  The lack of
sources suggests it an unwise "evaluation effort" -- find something
appropriate only to later discover it's not documented?  <frown>

> Actually, one thing that came to mind when I read your
> requirements is the much talked about Raspberry Pi. But it
> appears to not support PoE. However, see: [http://raspberrypi.stackexchange.com/questions/715/how-do-i-modify-my-raspberry-pi-to-be-powered-over-poe]

Raspberry Pi is just bare "compute engine".  No display, touch panel,
case, etc.  So, it buys me very little -- especially regarding the
ability to make a "commercial" looking device out of these.  I.e.,
I might as well just roll my own if I'm going to have to deal with
the packaging at that level.

The PoE is a non-issue.  I already have a little PoE "PD interface"
designed that I can piggyback onto an existing device -- within
reason (i.e., if the device needs a *single* power supply and fits
in the PoE power budget, then I can change a couple of components
and use my existing design/layout.
 
> The answer given there looks like an option you might be
> able to use with any tablet+USB-Ethernet combination you
> choose as well.

I suspect the USB NIC is going to end up being the only practical
route.  But, since I'm only making a couple of these, I can afford
to cobble a USB NIC *into* the tablet itself (i.e., gut the NIC,
remove the USB connectors and wire it directly to the appropriate
signals within the tablet).

I think I need to approach this from the bottom, up.  I.e., find
the products for which sources are available and then evaluate
those with regard to how suitable they are for my needs.  If I
can get reasonably well documented kernel sources, I should be
able to identify the actual hardware devices used and layer
whatever OS I want/need on the actual *drivers*, themselves
(i.e., discard the kernel itself)

I just downloaded one of the kernels for a Sony tablet to see how
realistic this approach is likely to be.  Unfortunately, the
GPL doesn't require the sources to be documented at *all* -- let
alone *well*!  <frown>

Thanks!
--don