Gus Wirth wrote:
Richard W. Ernst wrote:
Now that "smaller" LCD monitors (15 and 17") are dropping so low in
price, I thought it would be neat to find or build a VERY small form
factor embedded or other linux system to just drive a standard VGA
monitor (LCD or otherwise) with pictures stored on common memory media
like compact flash, SD/XD, etc. cards.
I'm surprised and frustrated at the commercial digital picture frame
prices. I don't want to duplicate work if this already exists. I
tried some google searches but came up with either too much, or wrong
direction for such a system.
My off the cuff ideas are:
1. Smallest form factor within reason, probably external/wall wart
power supply.
I'm not sure by what you mean "within reason". How do you envision the
system being hooked up? Does the PC have to bolt to the back of the
monitor, be some sort of desktop unit or can you hide it under the desk?
I'm not sure what I mean either... :) Hadn't envisioned it being
attached to the monitor, but neat idea. Just something small, say cigar
box sized, that would have power in, and analog video out connectors, as
well as some sort of memory card slot.
3. built in memory card slot. Really doesn't have to be able to read
multiple media, just simplest/cheapest/most common since it's a
dedicated system.
Nice but might make the board too expensive.
Also not necessary. You can buy CompactFlash devices that attach
directly to an IDE header or use an adapter. Fry's carries CompactFlash
IDE adapters for about $20 (on the expensive side) that can connect to
the IDE header using a cable.
An alternative is to use a computer that can boot from USB. Then just
use a USB Flash memory device. Puppy Linux fits into about 64MB and
leaves the rest for data. Quick, simple, easy plus easy to setup and test.
I was hoping for something that would allow physically changing the
media easily (for pic changing in another computer or whatever). USB
connected media readers are available very inexpensively. I think
compact flash/IDE devices are still pretty expensive, vs. a CD drive
(giveaways these days). Remember, I'm still a CB... :)
But the idea of booting from USB is thought provoking.
4. Video wouldn't have to be fast, just enough memory to display the pix.
Shouldn't be a problem on anything new with embedded video.
5. Operation would just be unplug, insert memory card with standard
format pix (how hard would it be to allow video and/or sound?) in root
directory. Then power up and it finds pix and displays them at a set
time period.
Manipulation of the rc.d stuff. I've just hacked Puppy Linux to make
some changes. It's not really hard, just tedious.
If you want to play video you will either need some horsepower or some
hardware assist. The video controller on VIA boards (UniChrome) and
NVIDIA have hardware support for XvMC (X Video Motion Compensation) to
help play MPEG-2 video streams (ATI supports accelerated playback under
Windows only). It's not useful for other video types because the MPEG-4
stuff isn't supported yet that I know of.
Video would be neat, but not really in my originally imagined scope of
this project.
My only real unknown is how to set up the system for differing
monitors/resolutions?
Steal the auto-configure stuff from Knoppix. If the monitor is new
enough it will provide DCC information which can be parsed to set the
resolution.
Anyone interested in this project as well? We could utilize the
installfests, or have separate get togethers if that'd be helpful.
I welcome your comments, suggestions, thoughts, links, etc.
I think this is going to be more expensive than you intend. What is your
budget?
This is/was a personal idea, so no budget set at all, just my
imagination getting me carried away... :)
For small form factor PC I would recommend one of the VIA mini-ITX
boards. There is a good market for them, both new and used. You can get
a brick power supply and converter so it operates fanless. If you don't
play video you can use the lowest power model they have available. Look
for boards with the Eden processor for fanless operation.
For even smaller form factor, look at nano-ITX. It measures 12cm X 12cm
(about 4.7 inches per side). Pretty pricey though. Looks like the
cheapest board is around $320.
Ouch!
Another approach would be to get a used laptop. Buy one with a broken
display and get it really cheap. Some good dissection skills can then
separate the broken display and then hook your new monitor up to the
laptop. You will probably want something that can hold at least 128MB
RAM. That way you can use something like Puppy Linux so that everything
will fit in RAM and you can use the CDROM drive for all your images. Or
a PCMCIA card with CF adapter for using Compact Flash. It would be even
better if it had a USB port since USB Flash Drives are so cheap.
I suspect this is the way to go for now and with being a CB in mind. I
see folks _asking_ for broken laptops on craigslist all the time, but
suspect they're just reselling the guts to others like me who actually
want to do something with them... :)
I have an old Compaq Armada 1550DMT that someone gave me. It is maxed
out at 80MB RAM. Puppy Linux runs on it using a little bit of swap. I
think with a few mods I can slim it down and get everything to stay in
RAM. Something like that might be a good project. We could call it
Picture Puppy (TM).
I like it!
Look at <http://www.barwap.com/cgi-bin/wiki.pl?Photo-Ix> for a
specialized distribution for doing this.
Some place to look for mini/nano-ITX stuff:
http://www.mini-box.com
http://www.logicsupply.com
So the mini-itx would be the lowest cost way to get small form facter,
and fanless design, is that correct?
I haven't mentioned PC/104 because they are very expensive compared to
the mini-ITX boards and they tend to be limited in onboard options. This
is to be expected because they are designed for industrial applications.
They PC/104 design allows for stacking cards as needed so they tend to
be more modular.
If you want to see some of what's available, check out
<http://www.versalogic.com>. This one also:
<http://www.tri-m.com/products/aaeon/gene6320.html> If you want prices
on anything you will have to contact the company.
Hope this gets you started. I'd be willing to help out on a project like
this at one of the installfests.
This year has been pretty bad for me in many ways, but I'm hoping for
more time in the new year and will plan on getting to installfests again.
Rich
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