Where Can You Buy Cheap, Tiny Motherboards?

Adam Ernst asks: "I'm trying to build a low-end tablet PC type device for giving tests to students in a classroom. The touch screen TFT wasn't hard to get and the WiFi shouldn't be too hard either, but the most difficult part has been finding a motherboard! I tried Via's Mini-ITX, but it was too tall at about 1.5 inches. The motherboard needs to be just three quarters of an inch tall; the length and width can't exceed 8 inches each, but the smaller the better. No fans allowed--this has to be silent. The -only- requirements feature-wise are that it is able to connect to a TFT-LCD, has either USB, CompactFlash, or PCMCIA for WiFi, and has enough power to run Red Hat or SuSE (the only Linuxes my IDE supports). No ports, no ethernet, not even sound. Preferably it would take straight power (just one wire in and one out, at some set voltage) so I don't have to mess with power circuits. Of course, the most important factor of all is cost, since it's for schools (preferably less than $100 in small quantities ~90 units)."

Comments

PC104

[bpb213]

The smallest motherboards I know about are the PC104 solutions.

Ive actually been compiling a small start off list, as I was researching them for robots.

http://www.advantech.com/products/sub_category.a sp ?Category_ID=1-D6LBY
http://www.bwi.com/

Also, I have various manufacturers of small form factor PCs that might be worth looking into (last ditch effort, ask where they get parts, or glue the lcd to one of them):

http://www.iwillusa.com/products/ProductDetail.a sp ?vID=179
http://www.norhtec.com/products/index.ht ml
http://www.openbrick.org/
http://www.littlepc .com/

Two options

[pyrofenix]

You can either find yourself a damaged laptop off ebay and strip the parts out of it that you need or you can get yourself a soekris board - downside of those are that it's going to cost about $150 each... Good luck.

Not at that price point

[omega9]

There are a few options, but you're not going to find anything for as little as you want to pay.

• MZ104: One of the most popular SBCs around. Small size and many uses. If you follow the pricing on that page you'll find you'll be paying at least $300/unit for the setup you need.
• PPC-E5: Looks to have almost everything you need, and then some. Unit comes with processor, RAM, disk-on-chip, and even a bundled touchscreeen LCD that fits nicely to the whole thing. It doesn't have USB/CompactFlash/etc.. and it also costs ~$1,000/unit.
• PCM-3350: Made by the same company as the PPC-E5 and actually a better option. 300MHz proc, CompactFlash, onboard VGA @ 1024x768, USB. Slap a screen on this thing and away you go. But, alas, it's still $348/unit and it doesn't come with a screen.
• ViewPad: From ViewSonic. Another all-in-one unit that could probably also work for you. At the time of posting, this unit is going for $200 (a decent deal). But it's only one unit, and it's still twice as much as your mentioned target price.

Like a previous poster mentioned, the only way you're going to find a device for around $100 is by buying bulk, used PDAs from eBay and they're still not going to do what you want them to. Hell, the PJRC costs $150 alone, and it's only an MP3 board.

Wanna make it cheaper at a cost?

[mnmn]

Ive been researching on these for a while, to build small embedded-sized PC systems for schools in Pakistan and Afghanistan. My aim was actually lower, to use 320x200 2-bit LCD screens ($20 or $10), cheap keyboards from chinese companies and one ethernet, while booting and running off compactflash with 32 MB ram using either Windows CE or qtopia on Linux.

Check out the SOC that is SiS 550. Its one chip that has the whole mobo on it and you only need to add IDE, TFT and RAM. In alrge quantities it was around $50, so you can do that under $100 but not in ~90 quantities.

Dont even consider PC104. Gathering used PCs is a lot cheaper, even basic taiwanese ECS-type mobos are cheaper there. Dont worry too much about fan and size for schools, else the price shoots up.

If youre into building embedded systems that can run Linux and uses tiny-X, you're in my league. I'm aiming for ~$50 for large quantities in low res LCDs using ARM MCUs. The cheapest Ive come across are ARM7TDMI MCUs designed for printers by samsung (~$7 each) but the ideal was cirrus logic (~$20) and includes ethernet and is quite fast.

For flash use Intel boot block. Others are expensive and low performance. Should really use compactflash since that will help change programs/OSes in the final product. Currently I'm seeking lowcost keyboard and mouse manufacturers in eastern countries and their quotes in ~1000 quantities. It should be possible they could use my autocad designs in which case I could really build a customized system.