Projects
Asus EEE PC: Remote On/Off
Apr 19th
I originally bought my EEE PC intending to use it as an upgrade/replacement for my current Car PC as it is much smaller, consumes less power, and uses a solid state drive (SSD) for data storage (meaning no moving parts while booting the OS and frontend etc).
There were a couple of problems I needed to overcome though – it would not be a case of simply swapping units over.
The first thing I needed to do was figure out a way to connect the EEE PC to my existing M2-ATX PSU so that the ignition was still able to control the PC turning on and off. On the existing system, this is done using a simple connection to the header on the motherboard. When the PSU recieves the ignition signal, it shorts these two pins together and the system powers on.
On the EEE PC, there is no header that I could connect such a lead to, so I had to rip things open and add one myself…
How to Get at the Internals:
- Remove all screws from the underside of the unit
- On the top edge of the keyboard, there are a couple of springy clips holding it in. Use a flat screwdriver to hold these in and prise the top edge of the keyboard out. The whole thing should slide upwards now and will be attached to the main chassis by a thin ribbon cable.
- You can unclip the ribbon cable to get the keyboard out of the way (carefully!)
- With the keyboard out of the way, remove the black screws holding the top half of the chassis down. You don’t need to remove the two either side of the screen. There are also a couple of plastic clips on the rear – by the screen pivots. These need prising apart (again – either a flat screwdriver or case splitter will be fine). The cover should lift off, revealing the motherboard.
- There are a couple of retention clips on the bottom side of the motherboard which can be released by sliding the motherboard up slightly. It should pop out.
- The VGA port also needs to be levered slight to release the side of the main board. When this is done, it should come loose and if you remove the mini-plug for the fan connector, the board can be removed entirely.
For the purpose of this guide, I was interested in the power button, located near the right hand side screen pivot point. The images below show the switch with what appears to be 5 soldered connectors. With a bit of testing and a flat screwdriver, I determined that the pins which needed shorting together to initiate turn on / switch off were the top two.
So I went about soldering some fly leads and threading them through the chassis, making them secure so they couldnt be pulled off easily.
Putting the EEE PC back together again and plugging it in / connecting the battery, allowed me to test that it all worked properly. Touching the two fly leads together (same as ignition ON) starts the PC up. Once booted, touching the leads together again initiates shutdown (same as ignition OFF).
Next problem is to sort out is the difference in voltage supplied by the regulated PSU (12V) and the input required by the EEE PC (9.5V). Stay tuned…
Car PC: Part 4 – The Installation
Jul 16th
With the hardware set up and all the software systems configured, it was now time to install the whole thing into the car itself. The whole process took a while to do and was split into three main chunks:
Wiring
The first job was to lay down all the wiring. This included power cable, speaker wire and extension leads for the screen.
In the above diagram, what is not shown, is that both the PC and Amp take their power from a thick power lead, fused, put through a distribution block, and run directly from the battery. Additionally, a switched positive connection is required for the M2-ATX to initiate remote startup and shutdown procedures. The easiest place to run this from, I found, was the existing headunit ISO loom.
The black, red and green connectors running to the screen in the diagram are the power supply and USB/VGA connectors. The power was spliced into a connection from the M2-ATX as the screen is designed to run from regulated 12V DC. These cables were run down the centre of the car.
Finally, as shown on the diagram, the audio connections run from the PC to the AMP via a 3.5mm audio jack adapter –> RCA/Phono connectors (blue), and then from the amp, I wired the speaker outputs to the old headunit ISO loom (purple wire pairs). All the speaker cable in the car was replaced with decent quality, shielded stuff. The picture below shows the cables being laid with the centre of the car bare as a work in progress.
Another note: When running the cables down the car, it is important to physically separate the power and data/speaker lines to prevent inteference which commonly manifests itself as alternator whine coming through the speakers. The easiest way to do this is to run the two sets of cables down either side of the centre console, or run them down either side of the car itself.
The above pic shows the cables running from the car interior, through the ski hatch and into the boot.
The Screen
With all the wiring in place, access to the wiring loom behind the dash was no longer required and so the screen was the next thing to fit. Obviously, prior to the final installation it had been tested for fitment so it was simply a case of refitting the centre console with the screen installed into the dash. The pic below shows what things look like behind the scenes on the dash:
The PC
And finally the PC was secured in the boot using metal mounting brackets beside the subwoofer and the wiring tidied up. All the USB data leads, VGA connection and the power and switched ignition leads were connected to the PC and Amplifier via the M2-ATX. Just to note that at this point, the amplifier being used is quite a basic one which is why it has not been installed ‘cleanly’. When I get a proper amp, the boot installation will look a lot tidier and I will gain a bit more boot-space.
You can see the PC beside the subwoofer and it fits snugly in the gap.
The ultimate plan is to create a ’stealth’ panel infront of where the PC is currenty fixed and fit the amplifier behind that as well. That should make things look a lot cleaner and give some more room (not that I use the boot a lot anyway).
The Finished Article
With everything done, here are a few pics of how it looks completed and installed:
Loading/resuming Windows XP at bootup:
The main frontend view (this is Centrafuse, but I usually use RoadRunner)
Sat Nav view
Media player currently playing Linkin Park
GPS and WiFi adapters installed out of the boot for better reception. They are hidden behind the seatbelt and secured to the plastic coving.
View from the rear seats.
Overall, the installation looks very OEM (to me at least! and boot excluded obviously lol). There is no evidence of the masses of cabling in the car and having the PC gives me a lot of functionality that I wouldn’t get with a regular headunit or even an all in one headunit costing a lot more.
There is also a lot of room for potential upgrades and further features which I can implement at a later date – and I have hinted at a few plans throughout the course of these posts… so this is basically a never ending project!
I hope it has been a good read and things do make sense. If you have any comments or questions, either post away on any of the posts (parts 1- 4) or just get over to the forums for anything a bit more in-depth.
Cheers.
Car PC: Part 3 – Software
Jul 15th
Part three of the Car PC saga 
Now that the PC itself was up and running and the screen and mount were completed, it was time to work on the insides of the beast, so to speak: the software – the thing that makes everything work!
The Backend
The PC itself was based on an extremely cut down version of Windows XP SP2. I removed unecessary features, slipstreamed hotfixes and drivers, and pre-installed some tweaks making a totally unattended installation that automatically installed everything I needed. This created a small install footprint and made the OS very quick to boot from cold / resume from hibernation.
I did experiment with using a 4GB compact flash card and CF -> IDE adapter as a boot drive mainly for the speed advantage (and solid state advantage), but due to the limited write cycles on CF cards, installing a standard version of XP (dynamically) would severely reduce the lifetime of the card. There are solutions to this (eg, using XP Embedded from Microsoft), but that involves a lot of hassle, so I opted to go for the old fashioned mechanical hard drive.
The entire system was tested indoors using a regular ATX power supply for ease of troubleshooting any problems – especially with the multitude of USB devices being used. Bluetooth partnerships were created with headsets and phones and COM ports configured for the GPS reciever and FM radio. When the system was found to be stable and with everything fully functional in it’s barebones OS state, it was time to install and configure the frontend.
The Frontend
The frontend is essentially what you see when you look at the screen. It is the software that is running and gives the user the functionality required from the PC in the car environment. There are several front ends available for use – some free to use, some not. Which frontend you choose is down to personal preference and before making a decision I tested two of the biggest ones on the system:
RoadRunner
This front end is free to use and is customisable both in terms of plug-ins and skins. It links to other external applications to handle various functions. Eg. Audio playback is controlled by winamp, GPS navigation can be controlled by Freedrive/Mapmonkey (maps are required from “Destinator” but need to be purchased) and DVD playback could be handled by PowerDVD, for example. It has a large userbase, because it is free and does the job very well.
Centrafuse
The other frontend I tested out was Centrafuse. This one is not free to use (there is a trial available), and comes in several different versions – the price of each is determined by it’s feature set. Again, very easy to work with – perhaps more so than RoadRunner, and there are a lot of plug ins and a few skins available. Centrafuse handles the majority of functions independently (as far as I can tell) as it doesn’t seem to call on other external programs as much as RoadRunner. One point to note is that Centrafuse does seem a little more resource hungry compared to RR.
Each frontend is very easy to set up and get working for basic functionality but things like phone control and GPS are a little more involved.
Now that system is fully operational, all that remained was to transfer some multimedia (audio and video) onto the hard drive so that there would actually be something to play! When doing this, make sure all files have correct ID3 tags otherwise when the frontend reads them, if you try searching for something by listing albums or artists, it will be a mess…
Transferring material to the PC in my case was simply a case of connecting to the wireless network and accessing network shares containing the albums etc that I wanted. This method will also be used when the PC is installed as the wireless link works from the driveway without any issues.
With everything as I wanted it, the final stage was to install the whole lot in the car. See Part 4!
Car PC: Part 2 – Fabrication
Jul 14th
Introduction
Following on from Part 1, this section is going to detail what I did regarding the most important thing in the project: the screen.
The screen is the one thing that you and everyone else who uses the PC looks at all the time so it needs to be visible – but at the same not distracting to the driver. It also needs to be accessible so the PC can be operated via the touch panel and ideally needs to fit in with the rest of the interior (I prefer things that look OEM and subtle).
What I decided to do was fabricate a mount for the screen into the centre console in place of the existing headunit. Rather than butcher the original console, I picked up another from a car of the same model as my own which was being broken for spare parts.
The Process
That done, I took the screen apart, separating the case from the actual panel and electronics inside, and provisionally secured the casing to the console using small blocks of MDF and screws:
With the main construct in place, it was time to start playing with the fibreglass.
Fibreglass Application
Fibreglass kits consisting of sheets of dry glass fibre, resin and catalyst are readily available at most DIY stores and it is commonly used in automotive applications for repairing/modifying bodywork. The fibreglass was applied in two stages: Firstly, a flexible sheet of dry glass fibre was placed over the area(s) which needed moulding to the console. The desired effect was that the fibreglass would form a solid framework to build on:
To mould the fibreglass to the required shape, the resin, mixed with a small amount of catalyst “hardner” was brushed into the sheet. This was all soaked in and the shape began to emerge:
It was important to remember not to cover the rear of the original screen casing so that the screen could actually be refitted!
A word of warning: The resin and hardner have a VERY strong chemical smell which lingers even when they are drying and this is something that really needs to be done outdoors or you will actually pass out from the fumes…
Filling and Sanding
After leaving the fibreglassed console to dry overnight, I was greeted with a rock solid finish which as you can see from the above picture is quite rough looking. To smooth things out, I used a product called Isopon P38. This is an easy sanding filler, commonly used in car body repairs – which again, comes in two parts – the putty and a hardner. This was spread liberally over pretty much the entire surface of the console which had been fibreglassed in order to fill the cracks and dips where the material had set.
At this point, the finish was irrelavent as when dry, the entire console was sanded down to give a smooth surface. Starting with coarse sandpaper and working through the different grades right down to ultra fine wet and dry paper, the whole thing was sanded blending the filler and fibreglass into the original console plastic. In my case, after the initial sanding, I wasn’t 100% happy with the finish and applied a bit more filler to certain areas of the console and re-sanded them.
Another word of warning: As with the fibreglass, the filler/hardner does have a strong chemical smell and when sanding, produces A LOT of extremely fine dust particles. Again, best done outside.
The Finished Article
The only thing remaining at this point for me, was to spray the console black again and fit the screen back into it’s casing. I used some standard grey primer on a couple of coats, followed by a few coats of black interspersed with some more wet and dry sanding to give a smooth a finish as possible.
It was then simply a case of popping the gear stick gaiter and screen and associated electronics back in:
The end result is a customised, one-off centre console which is designed perfectly for that screen. I think it looks OEM and sits quite well in the dash. It’s also easily accessible – being right infront of the gear stick.
Coming soon, Part 3: where I will talk about software this time….as always leave comments and stay tuned!
Car PC: Part 1 – The Hardware
Jul 11th
Intro
After my exams had come to an end, I decided I needed a mini project to keep myself occupied for at least a few weeks, so I decided as any normal, sane and non-geeky person would, to put a PC in my car.
I spent countless hours researching various components and determining what the best route to go down would be. Installing a computer in a harsh environment such as a car needs a bit more thought than your average ‘buy-the-components-and-slap-them-together-bob’s-your-uncle-fanny’s-your-aunt’ kinda thought process.
- There are space considerations. The entire computer needs to fit comfortably into a small area without sacrificing functionality.
- There are operating constraints. The computer should be sufficiently cooled to prevent it melting and destroying your car and perhaps most importantly, it needs to be low power so as not to drain the battery when working or when idle.
Specifications
Taking this all into account, the core specifications for the computer were as follows:
- CPU/Motherboard/RAM:
VIA EPIA M10000 ‘Nehemia’ This board is based on the mini-itx form factor (it’s really, really tiny), has an integrated 1GHz processor, graphics, sound, USB and LAN. It is extremely low power and as such runs quite cool. The integrated graphics is more than sufficient for in car purposes as are the other onboard components. Coupled with this platform, I chose to fit 512MB of RAM (mainly because that’s what I had lying around at the time – yes, I have have RAM lying around, ok?)
- Storage:
I chose to use a 2.5″ laptop hard drive as they tend to be a bit more resiliant towards shocks which will be ever present in an automotive environment. Alternatives include booting from a sizeable Compact Flash card and appropiate adapter but due to the limited write cycles as well as other limitations, this method, although fast, requires much more work on the software.
- Power:
To provide the computer with power I used an M2-ATX automotive PSU. Why not take a 12V DC supply straight from the battery I hear you say!? Well, besides from the obvious hassle of having to install a manual switch to turn the computer on and off, running a line direct from an in-car 12V source leaves sensitive PC components open to large voltage fluxuations. For example, the battery voltage can vary from 11-14V depending on the operating status and during engine cranking can jump up to 10’s of Volts higher.
The M2-ATX, which is rated at 160W, protects against these surges and also allows remote turn on of the PC via a switched 12V ignition feed. That is, when the key is turned in the ignition, the computer begins to boot.
- External Devices:
Nearly all the periphals connected to the computer are via USB. A mains powered hub was used and modified to work with the M2-ATX. Essentially, the 5V USB standby voltage was isolated within the USB terminal so that rather than drawing power from both the USB port and external power, the hub was exclusively external powered. Accessories included: USB GPS reciever, Bluetooth, FM Radio, Wi-Fi, USB touchscreen.
Stick it all in a well ventilated, home made case (containing custom hard drive mounts made from picture frame hooks!) and you have 1x Car PC.
Part 2 coming soon. That goes into details regarding the software used both behind the scenes and as a front end.