Re: [tlug] mounting LCD displays

["Andrew Errington" <a.errington@example.com>]

Hello.  There are a hundred and one ways to do this, so you just have to
pick one!  At a company I worked for we developed a product to do this-
basically a mini-ITX based PC running Linux from a flash drive.  It was
fanless with low power consumption, and of course it would drive any
monitor plugged into the VGA port.  The core of the system was a
locally-running Java app that rendered the information onto the local X
display.  The app fetched information from a central server, but it also
kept track of 'local housekeeping' such as, what to do if the server
became unavailable, turning off the screen at night (with DPMS) etc.

We tried a web browser refreshing itself automatically, but you still have
a problem if the server goes away for any reason, then the screen won't
refresh.  Either it goes blank and won't restart, or it stays frozen with
stale data.

One of the key design points was putting the PC and the monitor close to
each other, controlled via Ethernet.  It is of course tempting to use a
central PC with many video cards and loooooong cables, but that doesn't
work in all cases.  The mini-ITX system was cheap enough that we could
afford to put one with each monitor, rather than coming up with bespoke
installations for each case.

Even without the 'final' hardware you can play with software.  Maybe a
small control program (Python, Java, shell script) can poke your web
browser every so often, to make sure it's still alive.  Maybe you can run
X and then have a server render a new background image for the X session
and send it to the remote display.

If this is a commercial product you are designing then you have to think
very carefully about making it robust.  If it's some convenient hack
around the office then you can probably get away with having string and
sealing wax holding it together for a while.  Either way, you can probably
grab some hardware *right now* and dabble with a few ideas before you
start buying specific LCD panels and PCs and start making infrastructure.

We found that PC monitors were good for small 'local' displays, and Plasma
TVs for large 'public' displays.  In the end it comes down to how big you
want it and how much you can afford.  Don't forget, a large screen TV can
look very small in a huge open space, but look around you, in malls,
stations and airports you can see many examples of what you describe.

When you buy a display, make sure it has VESA mounting holes on the back. 
You can then buy many styles of wall/ceiling mount that just bolt on.

You could buy a system to do this, but maybe you want to play?  Perhaps
you could list some more constraints or resources you have and we can help
more.

Best wishes,

Andrew


On Wed, October 17, 2007 18:06, Conor McTernan wrote:
> I'm hoping somebody can help me with a question I have about LCD
> displays.
>
> I would like to mount some LCD displays within our office to display
> some images/information that is going to be updated on a regular basis
> (every 10-20 minutes, perhaps more frequently).
>
>
> We would like something large, but also something not too expensive, I
> was thinking something in the region of 21 - 24 inches and ideally
> widescreen.
>
> Does anyone have any recommendations on particular brands or models?
> I've been looking around and am not really sure what I should be
> looking for.
>
> Another question I have is how should I go about driving these
> displays. We will be installing 3 of them in 3 different locations. The
> idea at the moment is to view the images over the web, and stick Firefox
> in kiosk mode and have it refresh itself every 10 or 15 minutes. I'm
> wondering if I should stick a computer on each display or is there any
> other way I can get the images on there? Another way that has been
> mentioned is to stick a video card in a users machine in the office and
> drive it from thee (although I'm not sure how I'd go about setting it up
> so that only the browser session is spit out to the screen...)
>
> Anway, if anyone has any ideas or comments I'd appreciate them.
>
>
> Cheers,
>
>
> Conor
>
>
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