Headless solution / carputer as head unit?
I recently promised to set up a carputer in a friend's Jeep Cherokee (late 1980s). He buys the parts, I do the labor for free. Catch is, I've never done this before, and have only worked with desktop computers and the occasional laptop before.
This project began earlier today when he conveyed that the faceplate for his Sony Xplod head unit had been stolen and the unit is now useless. I made the suggestion he replace the HU with something a bit more homebrew, and after some persuasion, we (well, mostly I) started making plans. The system will consist of a computer running Linux mounted behind the rear seat, and a custom-made interface filling the HU socket in the dashboard, consisting of an LCD display, some buttons, and a slot-load CD-ROM in a homebrew enclosure, possibly built from the casing of his old HU. (VERY custom job, in other words.)
I still have a few kinks in my design:
As far as I've seen, nobody's actually tried to use a computer as a HU before, only connected it to their HUs which then manage the speakers and handle volume control. Has anyone ever replaced their HU with a computer? What extra steps/equipment was necessary?
I'm not sure how the buttons will interface with the computer. Is there a nice USB package to do this perchance? What have people used for buttons in their setups?
For controlling the CD-ROM, I'm leaning towards gutting a USB enclosure and using the electronics from it. I'm not sure how to power the CD-ROM though. It needs a 12v line, which the USB connection can't provide. (There's a 200mA limit anyway, not enough to power a CD-ROM drive by any stretch.) Should I run power wires from inside the computer across the truck to the dashboard, or hack up the enclosure's amp to run off the car battery (if possible)? Will the chipset misbehave if it's not receiving power except via USB?
As for the dashboard unit itself, I intend on building the unit by hand, but I don't know exactly how to do this. I've heard talk about fiberglass and something called "bondo", but don't really know what it means or how to use it / where to get it. Being a desktop computer technician by trade with no taste in aesthetics, I've never done as much as case modding before. How should I approach making this dash unit?
I was looking at using the Opus 150W power supply; however it's a tad expensive and driving up the unit price in a big way. I'm running on a tight budget ($500 for parts for dash interface, computer, and everything else) so $160+ hurts. Is there anything else that's reliable but still car-safe that I can fit in a Micro ATX case?
He's had numerous problems with theft before (in fact, that's how this whole project started), so is there any way I could mount the computer into the truck so it can't easily be removed? Same for the dash unit.