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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)."
Check out this site:
http://www.soekris.com/
They could probably build you a board, though it will not be less than $100.
Good luck.. I am looking for a similar board though I need 4 serial ports on mine.
The smallest motherboards I know about are the PC104 solutions.
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Ive actually been compiling a small start off list, as I was researching them for robots.
http://www.advantech.com/products/sub_category.
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.
http://www.norhtec.com/products/index.h
http://www.openbrick.org/
http://www.littlep
This
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.
Yes, I know that cheating is a problem. This motherboard is to be used with a proprietary testing solution that randomizes the order of the questions, the order of the choices, and locks down the computer to prevent use of messaging etc.
Adam Ernst
Netpliance used to have a product called iopener, which was essentially a small PC with an LCD display and a flash disk. CPU is usually an IDT Pentium clone at around 180-200MHz. It comes with USB ports and uses an external DC power supply. It sounds like it could fit the bill fairly well.
If you're lucky you might be able to find enough of these used to build your project around them, at least if it's a limited batch of 20-30 units. They usually sell in the $50-$80 range on eBay and surplus stores.
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.
I'm against picketing, but I don't know how to show it.
This is the group of people who have ported modern operating systems old atari computers and playstations... what was that about practicality?
I would start looking into (single board computers) SBCs or PC104 solutions. Some of the most common and easily available are made by Advantech.
I would also start checking out wearable computing sites and lists. The list to read is wear-hard.
These are basically iPAQs with no case or display. I've no idea if they'll be able to meet your price range, but it can't hurt to ask: http://www.applieddata.net
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.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
Mini-ITX motherboards are small and quite decent. Not as small as some of the PC104 solutions, but pretty small.
I believe the low-end ones are a little above $100 including CPU. A small Flex-ATX power supply runs $40. Smaller solutions (DC/DC power supplies plus 12V wallwart) run $70ish.
http://www.mini-itx.com/ has lots of Mini-ITX projects and info.
http://www.idot.com/ is a good place to get Mini-ITX goodies in the U.S.
retrorocket.o not found, launch anyway?
3.8x2.5 board, free (Windows) software, three boards for $62 (ready to drop chips on).