Archive for the ‘ Cars ’ Category

Asus EEE PC: Remote On/Off

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).

Chassic

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.

Keyboard

- 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.

Mobo Top

- 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.

Mobo Bottom

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.

Switch 1

Switch 2

So I went about soldering some fly leads and threading them through the chassis, making them secure so they couldnt be pulled off easily.

Fly Leads

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

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.

Wiring Diagram

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.

Cables

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.

Cables cont

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:

Dash Bare

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.

Boot state

You can see the PC beside the subwoofer and it fits snugly in the gap.

Wiring amp

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:

Finished

Loading/resuming Windows XP at bootup:

Loading windows

The main frontend view (this is Centrafuse, but I usually use RoadRunner)

Frontend

Sat Nav view

navigation

Media player currently playing Linkin Park

media

GPS and WiFi adapters installed out of the boot for better reception. They are hidden behind the seatbelt and secured to the plastic coving.

gps and wifi

View from the rear seats.

rear view

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.