Carputer I

Hello blog, I’m back, and you have a new address, bradford.law-family.org. OK?

Since spring of this year I’ve been involved in a project of installing a computer into my 2001 Ford ZX2. I’ve already purchased most of the components since June or July, but I’ve been so busy with school that I haven’t really done much with it. Well, I am pleased to announce I have started installing.

The plan was to get a computer that could fit under the passenger seat. That was a problem; any computer case that would fit the dimensions (4” tall, ≈12×12”) was really expensive. I finally decided to buy one that was no taller than 4” and I could cut down the other dimensions to fit. I haven’t really worked with metal since taking metal shop in junior high - so, the end result didn’t really look very pretty. Meh, it’s going under the seat so it’s not terribly important, but I will probably paint it up when I’m finally done.

The components I put into the case are as follows:

• Core 2 Duo E4500 (only 65W and can get as hot as ≈73C, perfect for the summer)
• Foxconn LGA 775 Intel 945GC Motherboard (Very small, and Foxconn’s have a good rep for quick posting.
• 2x512MB Ram I had from when I upgraded my home PC
• Some old 10GB HDD I got from a friend’s dad for free. For OS install.
• Some old 802.11g low profile wifi card I had from a couple years ago.

I do plan on buying a low-profile sound card (pci-e) for better sound because the onboard sound will only let me do either 4 channels plus an input, or 4 channels and subwoofers. I need the input for my HDZ300 (HD Radio), so I’m keeping my eyes out for a decent sound card that is cheap. What I’ve seen so far that will work are around $80, which I can’t really spend at this point.

To power this thing I picked up DSATX (220W) from mp3car.com. I still need to hook it up to the proper jumpers on the motherboard, but it seems to work like a charm. The reason I can’t use a regular AC power supply is because my car battery is DC power. In fact, an AC power supply simply converts AC (alternating current - think of a sine wave) to DC current (direct or constant current). The reason I still need a power supply to go from DC (what my car battery provides) to DC (what my computer needs) is that the power the car provides is too dirty for my computer. The voltage from my car battery ranges from 11V (when the battery is low) to 14V (when the car is running) and the computer needs a clean 12V (it can take +/- but its threshold is alot narrower than 11V-14V). In addition to that, some devices need 5V as well (a typical 3.5” HDD needs 12V AND 5V whereas a 2.5” HDD can usually run with just 5V - that’s why you can run a 2.5” USB HDD from just the USB port when 3.5” USB hard drives need power from the wall). This little power supply I bought seems to fit all my needs for this sort of application. Expensive little bugger though.

After throwing the computer together, I ran into a little hiccup. I needed to mount the LCD touchscreen (the main interface to the computer - can’t really use a mouse and keyboard whilst driving…) but I was having a hard time figuring out where to mount it and have it look “factory” - or at least “good enough”. A lot of guys on mp3car.com forums fabricate entire replacement bezels for the screens to place in their consoles. I don’t have time to learn how to fabricate so I’ll have to figure out another way. So, this little obstacle in addition to taking classes all summer put my project on hold yet again. During this time I did pick up a 500W (peak of course) 4 channel amplifier to replace the stock stereo amplifier. I will get from 40-60W RMS per channel.

2 weeks ago I pulled my project out and decided to sacrifice a Saturday and just install it and worry about the screen later. I didn’t want to try installing it in the snow either. So, November 29 I started the install.

Pulling out the seats was much easier than I expected. Each seat has just 4 bolts that I loosened quickly. The removed seats provided Julie with a comfortable seat while I worked on the car! In fact, we brought out a propane heater and with the stereo playing Christmas music her body and soul were warmed.After pulling the seats out, I pulled out the center console. It was all surprisingly easy. All these months I had been procrastinating installing the computer because I thought all this would be really difficult. Not so!

I needed power from the battery to the amp under the driver’s seat and then to the computer under the passenger seat. Last year, when I was going to install my subwoofers I ran a power cable from the batter to the back trunk. Only after doing all that work did I realize I needed a new stereo (that provided RCA out) to get a good signal to the subwoofer amplifier. But, at least that part was done. That cable was running along the door opening of the driver’s side, so I pulled that down under where the driver’s seat will be, and cut the cable to install a splitter. I then ran 8Ga wire under the carpet over to the passenger seat. I also split the REM (ACC) line in a similar manner.

Since I planned on putting the amplifier under the driver’s seat, I ran two RCA cables from the passenger side to the driver’s side. These will transmit the signal from the computer sound card to the 4 channel amp. Since each channel is discrete, I will have 4.1 (or 5.1) sound in my car!

My ZX2 came with the Premium Sound package, giving me a cd changer and an amplfier under the driver’s seat. In this I was VERY lucky. Most cars have the amplifier behind the radio

controls. The wires that run from the amplifier (radio) to the speakers end there. But in my case, the amp was already under the driver’s seat so all I needed to do was splice into the wire harness instead of running 8 wires from behind the dash to under the driver’s seat. Finding which wire went to which speaker posed a little bit of a problem. We had a stereo providing us with some delightful Christmas music. This stereo was the kind with detachable speakers, so there are speaker wires (powered) running from the stereo to each speaker. In the car, finding which wire ran to which speaker was as easy as pushing the (outside) stereo wire up against the (car) speaker wire and listening for which speaker was playing. After that I hooked up the amplifier completely, power, ground, REM, RCAx2, and speaker wires, and mounted it to the chassis.

Installing the amp took a looong time. But when it was finally installed I tested it with my Zune and it worked beautifully. It is going to sound great.

After the amplifier was all done, I started prepping the passenger side for the computer. I ran a vga cable (for the touchscreen), a USB plug (for the USB hub for GPS, Bluetooth, OBDII, etc), RCA cables (for the HD radio), and a small wire for 5V (for the USB hub) up to the console. I think I covered all my bases. With the passenger side prepped for the computer, I tackled the problem if powering the monitor. It came with a cigarette lighter adapter for 12V power, so I decided to make my life easier and just use that. I spliced into the existing cigarette lighter wires and hooked them up to the adapter for the LCD screen. To do this, I just drilled a little hole in the tip of the LCD adapter, plugged a wire in (12V) screwed it back together. I then attached another wire (GND) to the ground terminal of the adapter. I only had green wire so I couldn’t really color code it. I found out the next Saturday when I tested it that I made a lot of mistakes. In troubleshooing I blew the cig fuse about 3 times, along with the adapter fuse. But I think all the kinks are worked out…

The last thing we did was throw together the case. This was an intense undertaking - I just want to forget it now actually. The problem was that there was no really good place in the case to mount the HDD. Eventually we just cut up some of the scraps left from the case and fashioned a HDD mount that was suspended above the motherboard. It’s pretty solid, and took us about 2 hours :S.

We left around 1AM, totally exhausted. Julie was such a sweatheart, just patiently helping me out. She’s really patient with me, especially when I get into a frenzy trying to finish a project.

The following Saturday I spent a few hours putting the computer together under the passenger seat, troubleshooting problems with the cigarette lighter adapter, and getting the subwoofers ready to be installed as well. Tomorrow I’m going to hopefully get it up and running and also install Vista (nLited) on the computer. Vista has some really cool power management options that I’m going to take advantage of. I’ll also get the subs installed if I can.