This is VERY LONG, but informative at the same time if you've been curious about a computer in your car, but didn't know where to start! I guess I'll post it here, it's actually a combonation of a few threads, but seems most appropriate here...
--------------------------------------------------Found the parts (and began purchasing) the stuff I will need for a working computer in my car.
I just bought a 7" widescreen TFT LCD touchscreen monitor (NOT a tv...) off ebay for like $280. I've seen pics of the 7", and it's a nearly perfect fit in a double din slot (not too helpful here, but pre-98 consoles you can make it look real nice there. Since this is a touchscreen, it eliminates the need for a keyboard/mouse since windows xp/2000 have an on-screen keyboard, and this comes with software that makes an on-screen 2 button mouse. Of course the mboard will still have the usual array of inputs, so you can hook up a ps2/usb/wireless mouse/keyboard if you want.
Ebay authorized retailer for the screen.Review for the 7" Lilliput LCD--------------------------------------------------After that, I'm going to go with the somewhat-better method for the PSU.
The 2 methods of powering are these:
1. First Use DC-DC converter.
- Can buy a 200w unit for like $50. Takes in 12vdc and puts out +12vdc,-12vdc,+5vdc,-5vdc. I think that this used by itself will output fluctuating power if it's recieving fluctuating power, to alleviate, use an ITPS.
An
ITPS auto power sequencer and low dropout regulator will take in the 11-20VDC and output clean, steady 12VDC to the PSU. about $30. Another feature is it has an 8 bit processor that will automatically turn on/off the computer with a 12v switched source.
What it does:
- step one: key off: power is cut to the psu to avoid the slight drain from killing the battery (supposedly is less than that of a security system, but that stuff can add up and kill your battery).
- step two: key on: will allow power to flow to psu, and then a few seconds later will send the power on signal to the ATX power header on mboard.
- step three: key off: will send signal to the power header on mboard to allow soft power off.
- step four: key off: will wait about 45 seconds to allow for shutdown, then cut the power to the psu to avoid drain... back to step one. (note: if it takes longer than 45sec to shut off, it will just cut the power anyway, which could cause problems).
This PSU provides a standard ATX connector to the mboard, 2 molex connectors for devices, and 1 floppy power connector.
A big drawback of the ITPS is that it can only supply 70w, which is fine if all you're using is a laptop hard drive and dvd drive. you can bypass the regulator part and it will give the psu whatever it wants, but then all this is just a fancy power switch.
- drawback of this setup is it can't deal with less than 11vdc, which while starting, your battery might put out less than that. This means if you get in your car and turn the key on, but don't start right away, the computer will start to boot. If you go to start and power drops below 11v, it will just kill the power, which could destroy files on the hd. A way to eliminate this is to use a 12V lead acid 1ah battery and connect it paralell before the ITPS and use a diode to keep the car from using this battery to start.
You could also buy a
PSU that already has that stuff in it, and is not affected by starting the car (but expect to pay $150-$200 for a 90-100w unit).
This would be the best way to power the comptuer--------------------------------------------------2. Second: use a DC to AC inverter and use a regular 120VAC power supply.
This is the worst, but easiest method, and will end up costing about the same as using the multi part DC-DC convertor (and I think is affected by fluctuating volts, but I don't know, I didn't look it up, I'm not going this route). This method just requires you to go to walmart and buy an Invertor that has a rating equal or higher than the PSU you're using (probly 200W+). All you do is wire the invertor to a manual switch (or bypass the regulator on the ITPS and use it as a fancy power switch). Then just use a regular cord and plug the PSU into the inverter, off you go.
- biggest drawback is this setup makes A LOT of heat that you will need to ventilate somehow, and could get loud.
--------------------------------------------------After sorting out the other stuff, now you just need the actual computer. If you've got a computer lying around, use it! As long as the computer you build doesn't draw too much power, you'll be good to go (note: I used
this power calculator and determined a 1.8ghz p4 only uses 62W while playing a DVD).
VIA makes Mini-ITX boards that are fully featured with all the goodies you'll ever need in a car in a tiny package that hardly pulls any juice. They're pretty expensive, but looking that they give you a CPU and are fully loaded and are VERY small, I can justify the cost. I'm estimating the cost of one with a 1ghz processor is around $150 if you look hard enough.
You can buy a VIA Mini-ITX board with VIA C3 1GHz CPU bundled with the 200w dc-dc regulator and ITPS here. They're asking $234 (plus shipping) for that. So if you take their price of $180 for the board/CPU, then $50 for the dc-dc regulator and $30 for the ITPS, it's like getting the ITPS for free. I may end up doing this, but can't afford until after Dec. 1st. I don't know what the VIA board has for onboard video, but there is a PCI slot available (if you need the PCI slot for something else, and still want wireless, one of the VIA boards has a mini-pci slot on it, so you can have it too).
So if you have a hard drive, ram, and a dvd drive, this car computer will run you around $400.
If you have a lot of parts lying around, it might just cost you the dc-dc converter, ITPS, and LCD or just the cost of the LCD and an inverter.
If you have no parts lying around (like me) it will probly cost around $500-$600.
Also my Pioneer 7600MP has the IP-Bus connector on it, and they sell an audio device that allows me to input RCA to the head unit. That way all the sound that comes out of the computer will play through my regular speakers and sub.
--------------------------------------------------Just think of everyone that has an in dash DVD player, PS2, XBox, or any other thing like that. Having a computer will blow away all of that...
This is what you can do:
[list]
Play DVDs
Play PC games
Play PS2/Xbox games with an emulator
Play as many MP3s as you can fit on a hard drive.
Use GPS navigation equipment
Use an OBD-II to DB9 Serial to monitor your car and read/reset the codes. has free software on site.
Almost anything you can do with a computer at home...
I plan on getting this all working, so far just ordered up the monitor. gonna order the dc-dc converter and ITPS next and see what happens if I hook up this old PII 233 I have lying around, will post pictures and such when I get the stuff working!
Anyway, if you read that, you must be bored or 
! 
