SystemDotNet

aka Marauderz little PC
Last Updated : 1st May 2003

Carputer Status
Updated : 1st May 2003
So I've figured out that the inverter was receiving just enough power to run. But even IF it had enough power the inverter would overheat and shut itself off after 2 minutes. I've cut open a hole in the inverter and installed a fan on it, that seems to have solved the heat problem.

Components List
Updated : 5th April 2003
Shuttle SS51G Barebones Casing
Pentium 4 - 2.0Ghz
GEIL 512MB RAM
Geforce 4MX
120GB Maxtor HDD
Pinnacle PCTV TV Tuner
5.6" Composite LCD Display
300W 12vDC->240AC Inverter

 

Introduction

It all started when I bought the Shuttle BareBones casing, basically it's a normal computer casing except it's very very small, the motherboard that comes in the system can only barely accomodate one AGP card, one PCI, one 5.25" drive and two 3.5" drives. My initial intention was to use this as a replacement for my main computer system as it was seeing disuse ever since I got my consoles, so I was planning to shift the role from a main system to a file server (hence the 120GB hard disk).

The Shuttle (14k)

After using it for a while, a thought that I had previously returned to me and that was... putting a computer into the car. I previously hooked up with a friend and were thinking of using the VIA Mini-ITX motherboard and then custom building a casing over it. But that didn't work out because of time constraints, and also because... it's virtually impossible to find the board here! So now I have a small computer system, so all I need to do is stick it in the car right? Well here's what I went through...

Where do I plug the power in? Solving the power problem.

Well, if you've been fooling around with cars for a while you'd probably know that your car cigarette lighther or rather your car's power socket pushes out 12volts of DC. But our computers run on power sockets that use 240volts of AC power. So we really can't just plug our systems into the car and go. Reading on sites such as MP3Car.Com and you'll hear people talk about DC->DC power supplies that will directly power your computer through the cigarette lighther. But it's hard to find the components, or even the finished product!

The other way is to use an Inverter which converts 12VDC to 240VAC, which I just so happened to find in Jalan Pasar!

Power Inverter (11k)

This inverter is capable of delivering up to 300watts of power, more than enough of powering my Shutttle because it's power supply will only consume maximum of 200watts. If you're planning to get an inverter always get one that's provides more than you need. I'm no electrician so I can't tell you how to calculate the exact limit of an inverter. :)

So with this inverter, the problem with power is solved! Just plug this baby into the cigarette lighther then plug in your PC and wiola!.... There is one little thing to be aware of though, using this would probably put a HUGE burden on your car's battery! I'm trying to see how I can hook up a secondary battery in my car or something right now. :)
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The Window to Windows. Getting a display.

We need something for our computer to display on, a normal monitor is just out of the question cause first of all monitors consume lots of power (right?) and more importantly monitors are HUGE! Where are you going to mount a 14" monitor in your car? Luckily you can pick up lots of LCD screens from Jalan Pasar, but let's face it these LCDs SUCK! Their resolution is only 320x240 as I'm current testing out my first design for a carputer I picked up the cheapest one I could find (For RM438)

LCD Screen (12k)

And curse my lousy dumb luck! The screen seems to be defective, nothing is displayed on the bottom half inch of the screen... Looking to get a replacement soon.

(6th April 2003) : Looks like the screen wasn't defective at all, just that it didn't like the NTSC signal that was being pumped out by the video card, the screen works fine now after setting it to a PAL signal.

The screen unfortunately didn't come with a power supply, it only had a pair of red and black wires running off of it which the manufacturers assumed you'd know what to do with them (It was meant for in car use, not connected on your desk I guess) and connect them to a 12v power source. I *could* have bought a AC-DC adapter and plugged it into the inverter as well but that would be wasting space and current. So I bought a power socket, and a PC power splitter and came up with this...

Screen power plug (4k)

With this wire I'm able to power the screen directly off the Shuttle's power supply, the screen's 3 page manual states that it'll only consume 6watts of power should it shouldn't be too much of a burden... =P Then I had to get the power socket somewhere where I could plug the screen in, so I punched a hole through my casing (Or rather my father did, I'm still not too good with my power tools. Thanks Dad!)

Power jack on casing (5k)

Unfortunately I punched the hole somewhere where it made it inconvenient to close the casing... ughh..... But anyway the screen can be directly powered by the computer's power supply no additional power bricks necessary!

Monitor Mounted! (9k)
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The Software Issue

Well, as I said the screen's resolution SUCKS so I need to create a custom program for me to choose songs, video files, etc. etc. Maybe there could already be a media player out there which displays in large fonts, but.... I'm a programmer. ;) And here's a screen shot of version 1.0 of my program, pre image beautification.

M2Media Player v1.0
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Let's go for a test drive. Sticking it into the car.

Well, finally I come to the point where it's time to stick the unit into the car for a preliminary test drive to see how it'll work with the car moving around the various pothole ridden streets of Malaysia. First of all is to make we can hear the MP3's being played on the computer, that isn't a problem for me because I already have a preamp installed which has it's secondary input connected to a stereo jack, which basically means I can plug in anything that using a stereo socket for audio out.

Existing Radio And Amp (13k)

But of course the cable which I used was meant to be connected to something in the front seat not 3 meters away in the back, so I got an extension cable and to make sure there isn't much noise from the inverter I liberated two noise filters/magnetic shielding from my camera's USB cable (why the heck did they put it on the cable anyway?) and slaped them on the extension cable.

Extension Cable With Shielding (3k)

For this pleliminary test I installed the screen behind the front seat as I was just testing to see how stable was the computer when the car is in motion, so I'd most likely get a co-pilot to operate the system while I drive. Not to mention of course I still didn't have a way to remotely turn on the system so someone is going to have to run to the back of the car and turn it on.

Screen Location (11k)

The screen is held in place by two straps of velcro, from afar you might be wondering how that can be sufficient as the screen would probably slide around in the straps which are basically just covering over the screen's stand. Well thanks to my brother who suggested that I cut little squares off those anti-slip pads and stick them on the areas of the stand which the straps would pass over.

Anti Slip Pads On The Legs (10k)

This method surprisingly works! Trying to push the screen while the straps are over the stand to simulate slip movement would tear off the velcro that was stuck onto the comparment via double sided tape BEFORE the screen would move any more than a few milimeters. Either that or it's because I didn't push it hard enough!

Now I had to pull all the extension cables back into the rear of the van because there's where the system unit is going to be. Now one objective of installing a PC into the car was that I would do minimal irrepairable and noticable damage to the vehicle so I wasn't going to be cutting carpet anytime soon. Therefore wiring was secured by using velcro squares that stuck onto the carpeting of the car easily.

Wiring (8k)

For systems interface I choose the little handheld trackpoint for the moment, it's connected to the PC via a USB extension cable.

TrackPoint (6k)

And here's the system tucked in the rear of the car. It's a mess right now cause I might still think of moving it around first.

Da Trunk (9k)

So where's the inverter? Well the additional cigarette lighter jack is right behind the brakelight. And there was this one little problem when I first plugged it in... the inverter would power the system for a few minutes and then it'd shut off. And everytime the hard disk spun the inverter gave out it's low power beep. I refered to the manual of the inverter and it mentioned it should be directly connected to the battery for devices with a power rating of 200W and above, I did so and it *still* didn't manage to keep the system up for more than 2 minutes so I can only summarize that I need a bigger battery...

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The reactor, she can't take the heat captain!

So after a few nights of prodding the inverter and the car battery with a multimeter, I found out that the inverter WAS recieving enough juice to power the system therefore the inverter was shutting down because of heat problems. I tried doing the usual air cooling trick and popped open the lid of the inverter, that didn't work too well... guess our Malaysian sun is just too hot for it. So I tried pointing my mother's hair drier at it (on the unheated air setting off course!), and it worked PERFECTLY while the fan was blowing on the components.

I rummaged through my junk storage area aka my room, and I found this casing fan which my brother discarded previously. Said it was too loud and noisy.

Old Casing Fan (7k)

Well, in the car the fan would sound like nothing compared to the air conditioning so I striped off the molex connectors and directly clamped them onto the inverter's 12V input (Is 12V like a generic DC current since everyone seems to be using 12V) plugged it into the car and started another round of testing. The system worked PERFECTLY with a beep here and then when the car battery did some cycling (The car is not in motion.. just idling in the porch). But other than that the inverter didn't shut off unexpectedly due to heat.

Great, so now all I have to do is to stick the fan onto the inverter. I couldn't leave the lid of the inverter off as that's TOO BIG a hole that's just begging for stuff to fall into. So I had to cut a hole in the lid of the inverter, simple right? WRONG!! According to my father the lid was made of some sort of alloy which totally resisted being cut by the RTX's cutting disc. There was an incident where I just pressed the disc down hard on the lid hoping to accelerate the slow rate of cut... BIG MISTAKE, the RTX complained about the applied force by groaning and whining. The disc took a more aggresive stance, it shattered! One of the pieces grazed across my arm, the cut wasn't deep enough to start bleeding but it reddened and stung like mad while I applied disinfectant on it. I never recovered the pieces of the disc but I pressed against the cut to make sure non of it was IN my arm.

I apologized to the RTX and continued by gently cutting a grove into the lid with the tool, then continuing the rest of the line with your standard hack saw blade... (I gotta get a jigsaw!) It took about an hour but at least I didn't break anymore cutting discs.... more importantly I didn't get hurt any more =P. So after all my hard work I finally managed to cut a hole in the lid.... directly over the errr... transformer like thingy in the inverter... whatever it is it seems to be the one that needed cooling the most.

Hole in inverter (9k)

The fan is fastened by using velcro on the rim of the fan (yup.. I bought LOTS of velcro) so the final end product is the monstrosity you see below.

Modded Inverter (10k)

After coming to my senses, I realized something... I've just voided the warranty on my inverter!!! =P I hope it doesn't blow due to an overload! So now the heat problem is solved and the inverter can run the system... as to how long it can run I'll only be able to find out AFTER I finish my System shock absorbtion platform and mount the system on it. Then I can finally take it out for a test run!

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  Copyright Marauderz 2003