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

Originally Posted by captcol

From what I have seen and played with I am really liking win 7, and it seems to run beter on lower spec hardware than vista, I am tempted to change my media centre over to win 7. With the resolutions that are dealt with in car pc's I would think that win 7 woud lbe a good option and its free till mid next year - the RC anyway.

You know, I like what I've seen of Windows 7, and I've read a lot of good news about it. I might play with it on a desktop system. If it fails there, reinstalling a desktop isn't too painful, because I have other systems to use.

But I'll only have one system in the car, and I want it rock-solid reliable (well, as rock-solid reliable as XP can get). An unreleased system doesn't give me the expectation of reliable behavior. I did check the Centrafuse forums, and there are a few Centrafuse users running Win7RC successfully, but it's apparently a bit of a PITA to install.

I think I'll wait until Win7 is released -- and maybe even has a service pack -- before I consider switching. I have an unused Vista license I can upgrade to Win7, so it won't cost as much as an outright purchase. Or maybe I'll just get this system done with XP and use Win7 in the next generation unit.

Snakeskin to the Rescue

The OEM harness that comes with the M4-ATX is somewhat longer than necessary, so there were wires going everywhere, and I wanted them organized. I was looking around at the replacement harness parts I have on hand, because I wanted to build a shorter ATX harness for the PSU / mainboard connection. And there -- taken from a dead power supply -- was the solution.

I had snakeskin. This is the plastic stretchable cable cover that looks like the "Chinese finger puzzle" stuff we used to get when I was a kid. It's used on some power supplies now for cable control, and I like this stuff. If you push it together, it gets larger in diameter. Stretched out, it gets smaller, and nicely bundles the wires tightly together.

By pushing it together, and by separating the 24-pin connector into the 20-pin and 4-pin parts, I was able to work the snakeskin over the OEM ATX fitting and onto the cable. When I stretch it out, it keeps the bundle nice and tight. I ziptied the ends and have a clean-looking cable that routes easily, and the whole case looks neater. The good news is that no new cable is required, now.

I Bet I Can Flip That . . .
I made one other change. The ATX cable has the same wiring configuration on each end, so I flipped the cable. That makes one clean cable from PSU to mainboard. The accessory power cables normally come out of the PSU end, but now they come out of the mainboard ATX connector, right near where I need them, and well out of the airflow patterns in the chassis.

Now I can use the OEM harness with no change except the added snakeskin and small zipties, plus a couple of cable clips on the inside of the top panel. The result will be much cleaner routing for the myriad cables in the chassis. The extra length on the ATX harness will be an asset when working on the PC, and now it won't impede cooling airflow.

I'll get pix tonight when I get the cable clips and zipties installed.

*** EDIT: Pix are in post 678. ***

nLite and XP Pro

My EeePC has been operating well on an nLite'd version of WinXP Pro SP3. I left out a bunch of stuff I thought was unnecessary. It took four builds to get it so it worked well because, in each of the first three builds, I found I'd left required files out. In the fourth build, I got it right.

When I nLite the Intel Atom installation, I think I'll go with a lighter touch.

HiJackZX1 pointed out that he nLite'd his XP and removed only the language packs, and that change alone cut the total installation file size in half or more, and reduced his boot time. That seems like an interesting approach, and I think I'll go more in that direction for this installation. I may find a few things I'll leave out, such as Accessibility options, Games, and Media Player, but I think I'll be much more likely to let items stay in than I did with the EeePC's version.

I expect to use Standby most of the time, because I plan to take advantage of the very low power of this syetem and use a second, PC-dedicated battery system (to be installed later). That means boot time will be less important than the amount of time the PC takes to come out of Standby, and it means I can go a little easier with nLite.

This is a busy weekend, with not much carPC time. I'm cleaning up the cable runs in the chassis, but most of my attention is on building the new nLite'd version of XP Pro so I can start the software installation.

This Needs a Quick-Connect Plug

Power connections for this system are inside the chassis in the middle of the lid. I wanted a quick-connect at the front of the carPC (that's the open end deep in the dash), because I don't want to have to open the chassis to disconnect the power. I wanted to be able to install or uninstall the system by simply plugging or unplugging the power cable just like other ports on the system.

For that quick-connect, I saw three easy choices, and I liked them all because they're very compact and unobtrusive:

• A square 4-pin P4 power connector. I have the P4 plug from a dead power supply; I could match that to the P4 socket taken from a dead P4 mainboard. I like this because it has the locking tab; there's no chance the power cable will fall out.
• The standard flat 4-pin Molex connector used to power in-case accessories. I have both ends on hand. But it doesn't lock in place.
• A Radio Shack-type flat 4-pin Molex-type panel connector. I have the female connector on hand; I'd need to go to Radio Shack to get the matching male connector for the cable, for about $2.50. The Radio Shack connector is slightly different from the standard Molex connectors used on PC accessory power cables. This one doesn't lock in place, either.

Then there was the harder choice, because it's so bulky, and looks almost out of place on this small system: a standard PC server plug, designed for 30-amp 110V systems. In the long run, it's the best choice, because it's set up to carry all the amperage this system will ever draw, and it has a swing-down locking mechanism to hold the power cable in place. And so that's the way I decided to go.

There was a downside to using it: I have to lower the back of the mainboard (it's at the front of the chassis) to allow room for the bracket that holds the power port, or it would block access to some of the other ports. All that takes is a pair of longer mounting brackets.

I won't even need to make the cable that connects the PSU to the jack; I'll use the cables that came with it, but shortened, to keep it neat. I'll use the standard 30A power plug to connect to it, and run that to the battery (+) and battery (-) terminals through a wiring block. I'll tie the ground line into the switched ignition line for on-off control.

That's just the right wire to feed to the M4-ATX. With the low power draw of this system, the 250W PSU will mostly loaf, even at the system's maximum load. At 50% load or less, the M4-ATX is rated as 95% efficient, meaning it produces relatively little heat until it gets loaded up. In this installation, heat shouldn't be a problem.

Tasks remaining on the power installation:

• finish the in-case connection for the power port
• finish and install the extended mainboard supports
• remake the test cable that plugs into the cigarette lighter adapter to use a 30A plug
• revise the fan power cable to plug into the PSU
• install a holddown for the ATX cable so it doesn't flop around in the chassis

I may be able to get them all done Sunday morning.

Got That List Task Done

Sunday morning was all for work on the chassis. It's is pretty well done, and everything is just about ready for the software install. All the items on the list in the last post are complete. (We spent Sunday afternoon working on the lawn tractor: repair, rebuild, re-grease. We replaced one blade and sharpened the other. Boy, it really runs better-smoother-easier, and cuts way cleaner.)

Josh helped with the soldering; some of it takes threee hands. That man can solder.

There was one thing I did differently. Instead of just lowering the front of the mainboard to clear the power port, I also raised the back of it by replacing the standoffs with simple washers. The mainboard now sits almost dead level, and the hard drive has plenty of breathing space.

Pics to follow.

Top Panel Pictures

The top panel is complete. Well, almost complete; there's one more cable holddown to be installed in the top left corner. It will be similar to the one between the fans, which is a ziptie bracket that's riveted to the panel. After installing the top panel, I noticed the cable hangs down a bit in the corner. The second ziptie isn't crucial; it will just look better.

It's hard to believe this is the same ATX cable that was miles too long. The only issue I see remaining is what to do with the extra accessory cabling. I'll have to ziptie the unused parts out of the way inside the end panel.

Click images to enlarge.

I used heatshrink tubing on the wires for the power port and the fans because it keeps them neat and prevents them from sagging into the chassis and blocking the airflow. It's another layer of insulation and wear prevention, too.

The power port bracket is a piece of 1-inch (25mm) aluminum angle -- it's .042 inch (1mm) thick -- with a hole cut in it for the port, plus holes for the fasteners. I cut the hole for the port by drilling 3/16-inch (5mm) holes in the corners, because that provided the right radius in the corners to match the power plug being installed in the hole. I added a few more similar holes close enough that I could get a saber saw blade in, and used the saber saw to cut the rest of the hole. I finished the hole with a file. Here's a closer look at the bracket.

More pictures are on the way . . .

Power Cabling

I rebuilt the power cable used for testing. The original was a very light duty unit, and it was wired with the cigarette plug on one end, and directly into the carPC on the other. Except for the cigarette plug, it's all gone away.

The new cable is heavy duty -- 12 gauge wire -- like the one to be used in the car, and as recommended by Mini-box, the manufacturer of the M4-ATX. It also has the 30A, 110V plug for the carPC to match the new power port. I soldered in the cigarette plug on the other end where it will plug into the 110V-to-12V converter. Because this is a test cable, I soldered the third lead -- the one that will normally come from the switched ignition line -- to the hot lead. When this cord is used during testing, the system will think the ignition is on all the time.

The power port itself (see post 678 for a picture), is from a dead server, so it came with the wires already soldered on. I just had to cut them to length and solder on the ends that screw into the M4-ATX. The port's wires are 12 gauge like the cables I'll plug into it, so the system will have 12-gauge wire throughout.

Mainboard Remounted

I mentioned earlier that I'd revised the mounting of the mainboard to accommodate the larger PSU and the added power port on the top panel. Here's the result of those changes:

Click images to enlarge.

The front brackets (to the top and right, above) are the same, and still use the standoffs, but I redrilled the holes for them to place the brackets much lower in the chassis. The only downside of this is that the front corners of the mainboard are below the edges of the side panels.

The rear brackets (to the left and bottom, above) are mounted in the same holes, but I flipped the mount brackets so they're below the mainboard, and the standoffs were replaced by steel washers.

Here's an image looking through the chassis from the touchscreen end:

When I looked at this picture, I saw that the ATX cable -- the one you can see sagging down a little on the left side -- needed extra support. It now has an additional cable mount to hold it up in that corner, so there's no more sagging.