Scion xB '06, in-dash Atom 330, Lilliput 889GL; details, pictures, links. Index: pg 1

**HiJackZX1** · 06-21-2009, 12:10 PM

Originally Posted by rdholtz

Choosing the Drive System

A while back, HiJackZX1 said,

I considered the Solid State Disk idea. The 4GB SSD in the EeePC works great, and a similar device could work just as well in this installation, too. The EeePC boot has been fast and stable, and it appears that SSDs are a lot less likely to fail suddenly in operation. I see two problems with SSDs: (1) cost -- way more than a hard disk, and (2) reusability: we only get so many fast writes on an SSD and then they get fragmented and slower. It looks to me like SSDs are best used -- right now, anyway -- as boot disks; it's not a good idea to use them as day-to-day drives that get a lot of re-write action.

That changes with drives that are basically big boxes of DRAM and that can take all the writes we throw at them. But those drives are volatile; they need some power to them all the time. If the system dies from battery failure or long disuse, all the information on that drive is gone. For mobile solutions, where power can be dicey, that's a big negative, and non-volatile disks are probably best.

I was originally planning to use both SATA and IDE drives. I planned to boot from the 2.5-inch 60GB SATA drive I built for my original installation over a year ago, and use the 2.5-inch 60GB IDE music hard drive alongside it, since the Atom board has both IDE and SATA interfaces. But . . .

Oh, Wait a Minute . . .
Then I realized I have a 120GB 2.5-inch SATA drive from a crushed laptop, and I can use it in the system, too (assuming it works -- I haven't tested it since salvaging it, but the damage was to the screen and mainboard, not the drives). It's a Hitachi drive that runs at 5400 rpm; for a laptop drive, that's pretty fast. Realistically, 120GB is vastly more space than I need. I'll probably use the 120GB drive as the main drive, and use the smaller SATA drive for a full-time backup system in case of primary drive failure. It would have a duplicate installation of everything on the first drive.

Although the cabling on SATA drives is much cleaner, my experience with them -- at least with SATA I drives -- indicates they're also more prone to failure, and when they fail, it's with little or no warning. I've had two go out on me, and there was no time to do a last-minute pre-mortem backup; they died all of a sudden and stayed dead. That means loss of the SATA drive would kill the carPC. If I were in the middle of a trip, that would be ugly, since I probably wouldn't have a chance to reinstall the system while traveling.

The secondary drive would handle that issue. And I'll keep the 60GB laptop IDE drive as is, in its USB chassis, for file portability.

The SSD might come in later, but I'll run with the SATA drives I have for now.

Mine is setup similar. I have a 250 GB Toshiba drive which is partitioned. 40 GB goes to images of the main drive (later the image for the 6 other PC, since they will all have the same hardware exactly, I need only one) and or install files. The rest is media for movies, music and game ROMS. The other drive, the main OS drive, is a SSD. I made the mistake though of buying a cheap one that has so many stutters, slow installs and what not that I am considering using it as a paper weight. If you do go SSD, save up and get MTron SSD, they are pricey, but they have great reviews. Kimota uses one in his setup and its amazing fast, you can most def tell the difference. Since my install has become so costly, ive decided to just go with a 60GB Sata drive. I have to use SATA since my IDE is used by the DVD ROM, USB DVD didnt work to good on my setup. I have never lost a drive in the car, so I dont think a SSD is needed. Cant wait to see your finished setup, it will most def be finished before mine, lol.

**rdholtz** · 06-21-2009, 01:50 PM

Originally Posted by HiJackZX1

I have to use SATA since my IDE is used by the DVD ROM, USB DVD didnt work to good on my setup.

Couldn't you use the IDE with hard drive primary and DVD secondary, or does your board only support a single IDE drive?

**HiJackZX1** · 06-21-2009, 02:34 PM

Originally Posted by rdholtz

Couldn't you use the IDE with hard drive primary and DVD secondary, or does your board only support a single IDE drive?

It supports 2, but I use a special long IDE cable so the DVD rom can reach to were I want it to. If it had 2, then I would have to try to find a way to mount the HDD with it.

**rdholtz** · 06-22-2009, 07:16 AM

Hard Drive Mounts

I needed to build the drive mounting system, so I stopped at Home Depot for some grommets that would work with the M3 machine screws used to mount laptop drives. Bad news: the smallest they have are for a 9/32-inch (7mm) shank, which is way too large for M3. That meant the rubber-mounted drive idea was aborted. I guess I could have waited and dug through McMaster-Carr or a similar catalog, but I just bulled on ahead and changed the design. I skipped the grommets, but retained the Velcro hook-and-loop fastening system.

More Aluminum Angle
In the interest of keeping this very simple, I built the brackets from 1/2-inch (12.5mm) aluminum angle. I made the brackets 3-1/2 inches (89mm) long, because that's 1/2 inch (12.5mm) longer than the distance between the mount holes. I added 1/8-inch (3mm) holes spaced on 3-inch (76mm) centers, as close to the edge of the angle as possible; they're centered about 3/16 inch (4.8mm) from the edge. That lifts the hard drives up off the bottom panel of the chassis, and allows some cooling airflow under them. I put Velcro hook-side strips on the bottom of each bracket; they hook into Velcro loop-side strips that will go on the bottom panel.

Here's how the brackets looked, as made, and as installed on the drive. In the picture, both parts of the Velcro are on the drive.

Click image to enlarge.

At final assembly, I'll peel the Velcro backing off and press the drive in place. After that, I'll be able to remove the drive by just pulling it up and separating the Velcro. It won't vibrate off or move around. I expect the Velcro will provide enough extra shock damping to help maintain good drive health.

**rdholtz** · 06-22-2009, 04:21 PM

Some Progress on Saturday

I got a little work done, but Saturday sure wasn't as productive as I'd hoped. I ended working/playing at the computer store all day, although I did pick up some standoffs and screws to help finish up the system.

PSU Mounted to the Chassis
After lowering the mainboard, the power supply unit bolted right into the underside of the chassis top panel, using short standoffs -- about 1/4 inch (6mm). I put it as far forward as I could to keep it clear of the fans. If I'd recognized in the design phase that I was going to use the M4, I'd have moved the fans further forward, but it's too late to do that without making another top panel. I'll leave that change for Version 2 -- if there is a Version 2.

Pics tomorrow.

Mounts Re-Fastened
The rivets in the lower mount brackets had gotten loose from all the installing / removing / reinstalling during fit checks, so I installed the chassis in the car, marked the final angle on the brackets, and replaced the rivets with 6-32 screws and nuts. They're tighter, now.

**rdholtz** · 06-23-2009, 09:31 AM

Sunday was Better

Sunday was much more productive, and I finally got the system ready for testing.

Wiring Installed
Using the wiring set that came with the M4-ATX, I connected everything. The cable set includes the double-ended 24-pin ATX connector thhat runs between power supply and mainboard, plus the double-ended 4-wire P4 power cable, the double-ended 2-wire mainboard on/off cable, plus the power cables for peripherals. I added a data cable for the hard drive, and so it should be good to go.

12V Power System for Testing
I grabbed an old accessory plug (for what used to be called the cigarette lighter) and checked the polarity, then soldered on the ends for connection to the power supply. The hot lead splits and goes to the "switched" lead, too, for testing.

For a power source, I'm using a Coleman 120V / 12V converter that usually powers an in-car cooler. Here's how that looks:

Click image to enlarge.

I can plug into house current to do my testing and software installation, then unscrew the leads and power it from the car.

I haven't run power wires in the car, so that's on my list of things to do. And boy, I sure wish I'd had the foresight to do that in-car work when the weather was cooler. It was almost 100 degrees F (38 degrees C) here in Georgia this weekend. Even with a big fan, it was hot working in the garage. Looks like I'll have to dig out the portable air conditioner and give that a chance to keep us cool.

CarPC pics are taken. I'll get them up.

**rdholtz** · 06-24-2009, 12:01 AM

Now it's Ready

Here's how the system looks, ready for testing, with the top panel pivoted open:

Click images to enlarge.

You can see in that picture that the ATX and P4 cable harnesses are pretty long for a small chassis like this. For the final installation, I plan to make shorter harnesses from some other cables I've taken from dead power supplies.

Here's how it looks from the other end:

The pass-through power connector is for the fans; after testing, I'll connect the fan wires to a single plug going to the fan port on the power supply, so that part of the cable snarl will go away. I expect to shorten the accessory power cables, too.

**HiJackZX1** · 06-24-2009, 12:34 AM

There are 2 things I hate, the case is beautiful, your planning most def paid off. One thing I hate is the wiring from the M4 to the MoBo. You did great laying it out, but its all way to long. Thats an easy fix I guess, just shorten them. The other thing is the size of the M4..... I thought it was smaller. Its almost the same size as the OPUS!!!!!!!!!!! Im glad I saw your pictures because it gave me the scale of the M4. Next time if I need case made, I'm paying you a visit, lol.

**captcol** · 06-24-2009, 12:52 AM

A nice snake for the power lead along the top plate and then dropping down to the mobo etc would look awesome and really finish the project off. With the attention to detail that you have shown with this aspect of the install I can't wait to see the quality of the fully completed system.

Hows the software side going?

**rdholtz** · 06-24-2009, 04:24 PM

Originally Posted by HiJackZX1

There are 2 things I hate, the case is beautiful, your planning most def paid off. One thing I hate is the wiring from the M4 to the MoBo. You did great laying it out, but its all way to long. Thats an easy fix I guess, just shorten them. The other thing is the size of the M4..... I thought it was smaller. Its almost the same size as the OPUS!!!!!!!!!!! Im glad I saw your pictures because it gave me the scale of the M4.

I absolutely agree that the ATX and P4 harnesses are too long. After fooling around with various routings, I noticed that I could use these harnesses by using a twist-tie to make a loop that could sit inside the end panel, comfortably out of the way, and not blocking any cooling airflow. That's a good temporary fix, but I think I'll want to make shorter ones before the final installation.

Yes, the M4-ATX is big, at 4-7/8 x 4-1/2 inches (124 x 114 mm), including the connectors. The DSATX, which I also considered, is smaller, at 4.25 x 3.5 inches (108 x89 mm), so it would fit better.

Originally Posted by HiJackZX1

Next time if I need case made, I'm paying you a visit, lol.

Thanks for the kudos.

The easy way to get a case like this is to get one from blk02si. He can custom-make whatever you need, and at a surprisingly reasonable price. Although I haven't had my hands on any of his work, it is invariably beautiful in the pictures. His customers all seem happy, and after he sells a chassis, he helps troubleshoot the PC installation. That's good customer service, and it's enough to make me think he'd be my vendor of choice.

I did this chassis myself to increase my knowledge of sheet metal work and to build up my tool set. Although I didn't start out intending to do it, I ended up showing that it could be done with a minimum set of tools. It's been quite an education, and a fun engineering exercise to figure out ways to do things.

Originally Posted by captcol

A nice snake for the power lead along the top plate and then dropping down to the mobo etc would look awesome and really finish the project off. With the attention to detail that you have shown with this aspect of the install I can't wait to see the quality of the fully completed system.

Yes, I agree, wrapping the harness will make it look much cleaner. I plan to leave just enough length to let me flip the cover open sideways.

Originally Posted by captcol

Hows the software side going?

I fired it up last night, and PC and touchscreen lit up just fine. I looked through the BIOS settings, changed a few, and high-fived myself.

But it was pretty late, and I was too tired to be sure I was on top of the installation, so I decided to wait. Since the hardware is sorted out, software installation is the Next Big Thing, and I'll start tonight, I hope.