Information, Papers and Tutorials

Front of Car Computer
Front of Car Computer
Being the sort of person that likes to fiddle with technology, a month or so back I decided to install a computer inside my car as I found many people had already done from looking around the internet. The advantage of doing this is you can integrate many functions into one unit including the following :-
- Store all music on the computer and create playlists from that music.
- If using a USB based radio, this can be controlled from the same system.
- Satellite navigation automatically muting anything else while it reads out directions.
- Hands free phone support again automatically muting anything else when a call comes in.
- E-Mail client that automatically reads out new emails.
- Camera control.
- Voice control for all of the above.

Back of Car Computer
Back of Car Computer
Computer Hardware
While prebuilt units are available with or without an operating system + front end software, personally I just choose to build from scratch. If you have built computers in the past, this is even simpler than that due to there being less components so you won't have a problem.

I purchased all required components including the case from LinITX. I went for :-
Enclosure: VoomPC 2
Motherboard / Processor: Intel D945GCLF2 ATOM with Dual Core 1.6Ghz (Most Mini-ITX motherboards come with the processor fitted)
Memory: Kingston 2GB DDR2
Hard Drive: Seagate Momentus 500GB SATA
Power Supply: M2-ATX 160W

You can optionally buy a slimline CD / DVD drive that will fit inside the VoomPC enclosure but I just decided to hook up a standard one only for installing Windows with. Eventually I did fit one though due to the number of times I found myself needing one.
Car Computer with Standard Desktop Power Supply
Car Computer with Standard Desktop Power Supply
As mentioned above, it is very easy to fit all this together. It is just a case of screwing the motherboard and power supply board down, securing the hard drive / optical drive in place, connecting the required cables and then screwing the case together.

I quickly found the 2GB of RAM was a mistake and dropped it down to 1GB. The reason for this is that it hibernates and resumes from hibernate much quicker.
Car Computer Ready to go Inside Enclosure
Car Computer Ready to go Inside Enclosure
Fitting into the car was easy with it just requiring Ground, Permanent 12V and Ignition 12V. I added a switch onto the ignition 12V as this allows me to stop the unit even turning on when I am going somewhere when it isn't required.

VoomPC Enclosure Indoor Power Adaptor
VoomPC Enclosure Indoor Power Adaptor
It didn't take me long to get annoyed by the very loud fans that were part of the VoomPC case. I replaced these with some ones I found on eBay.

Using Indoors
The quickest way to power the unit indoors is simply to connect the motherboard and any drives directly to a standard computer power supply but I ended up getting a VOOM Home Power Adaptor along with the AC Power Adaptor (I already had plenty of Clover Leaf Power Leads so didn't need one of them) as the computer was ending up indoors frequently.

External Devices
For GPS, I choose the Globalsat BU353 as it had a lot of reviews. It was all detected by Windows without any problems and works fine in GPS applications.
GPS and Wireless Adaptor
GPS and Wireless Adaptor
I did find I needed to use XPort in order for it to actually work with any navigation programs, though.

As I wanted to be able to do quick synchronisation of music as I add more on my desktop computer, I purchased a Buffalo WLI-U2-SG54HG wireless adaptor. I choose this as it mentioned high gain and is attached with suction cups so I can just attach it to a window.

I ended up getting given a Scan Tools OBD Link which I also added in. This allowed me to use a Centrafuse plugin that increases and decreases your volume depending on your speed as well as keep an eye on the engine.

I had two cheap Bluetooth dongles fail on me rather quickly and in the end purchased the Mobile Computer Solutions dongle with it being Centrafuse recommended. I have not had any trouble since.

As most motherboards only give you 4 USB ports, these can get used very quickly. I tried some bus powered hubs but with what was getting connected, the computer didn't like this. In the end, I purchased 2 CarNetix powered USB hubs. These are directly powered by connecting Ground, Permanent 12V and Ignition 12V along with the USB cable.

Finally, after getting annoyed with having a keyboard in my car, I purchased the Logitech diNovo which is a mini keyboard and touchpad that I can slide into the door storage area.

Operating System
Initially I started on Windows XP and then various slimmed down versions like TinyXP but I was finding that in hibernation these would sometimes take a long time to go into hibernation or take a long time to resume for no real reason. The main problem with it taking a while to go into hibernation was the power supply cuts the power after 1 minute so on turning the ignition back on, the operating system was doing a full boot.

After testing Windows 7 on other computers, I decided to give it a go on my car computer and after tweaking a few settings, I am very impressed. It solves the above problem and the other small problems I was having. One thing I will say is you should use the 32 bit edition as drivers for the 64 bit edition tend either not to work or not be available. The wireless adaptor I purchased was one such problem.

Front End
Obviously once you have an operating system installed, you need a front end to allow you to easily touch the screen to control things. At the moment, there are two front ends which I would call "supported" and would consider using. They are Centrafuse and Ride / Road Runner.

Centrafuse is a paid product and comes with support. Personally, this is the one I like and choose as it is a fully integrated solution and has a nice interface. Ride / Road Runner is free and more flexible but requires a higher degree of technical knowledge to get things working I have found.
I would personally recommend anybody new to this area and without a large amount of technical knowledge goes with Centrafuse.

Leaving in Standby
Initially, I played around to get standby working on my car pc so startup would be near instant. My first attempt was simply to get new car battery with a much higher storage capacity. This appeared to work for about a week but after that I found that the car would not start as the computer in standby had used all available power.

My next attempt was with the PicoUPS 100 (also tried also connecting the DCDC-USB to this to increase the output voltage so it would charge the battery) and the PicoUPS 120 units that had become available combined with SLA batteries from Maplin (highest capacity available). This also failed and I found that after 2 days the computer's power had been cut overnight and it was doing a normal boot when I turned on the ignition.

Simply put, I would NOT advise anybody try doing this unless they are driving at least 2 hours a day. This is about the time that I have found would be needed to either keep the main battery charged or a secondry battery.

For the main display, you really have 4 options :-
1. A single DIN solution with either a mechanical slide out or manual slide out.
2. A double DIN solution with an always visable screen.
3. Dashboard replacement parts. This is where you take out a section of your dashboard and replace it with a part already availble to house a screen.
4. Fabrication. This is where you buy a screen panel and mould it into your existing dashboard.

2 and 3 are the easier and better options but these may not always be possible. I have left out visor and headrest screens as these are really for additional display rather than the main display.

After a lot of searching around, I decided to go with the Lilliput GL701 pictured below - A single DIN mechanical slide out solution. The reason being that I only have a single DIN slot available and didn't want to go down the fabrication route. I did have concerns about this unit having a lot of complaints regarding the mechanical side going wrong but many people had said the newer versions of this model work much better.

Fitting this didn't take too much effort. Ground, Permanent 12V, Ignition 12V and the VGA connector are the only required cables.

My initial plan was to use the amplifier built into the display but I found a few problems with that :-
1. The screen had to be slid out for audio to start playing. There is also no way of automatically having this happen. Also, I did not really want to always have it open when just driving short distance.
2. The maximum volume isn't very loud.
3. I had a weird problem where by I would get bad sound quality when I was driving faster.

In the end, I just purchased a dedicated amplifier from my local Maplins. It was just a 2 channel unit that says Nikkai on it which appears to be a brand Maplin use for own brand products. It had good reviews online and I had no problems after fitting it.

Similar to the screen, only Ground, Permanent 12V and Ignition 12V need connected to power it and then a left and right channel phono connector to the computer for the audio.

I started off for a month or so without a radio as I had obviously removed the factory head unit. The display had a radio built in but I couldn't use this anymore when I shifted to a dedicated amplifier.

My first purchase was a Silabs USB Radio. Using just the wire that comes with it as an aerial, I found it unusable. When I connected it up to the aerial on the roof, it was a little better but not much.

Next, I tried the HQCT (High Quality Car Tuner). This was better than the Silabs unit but had some bad interference problems.

Ultimate Computer DAB / FM Radio
Ultimate Computer DAB / FM Radio
While just putting up with the HQCT, I was following a topic on the Digital Car forums regarding a few users who had managed to find a combined DAB / FM chip and build a power / control board for it. One user there improved it removing interference problems it also had and then sold the design onto me after I found a source of the modules that others could not.

The unit (Ultimate Computer DAB / FM Radio) works with DAB, DAB+ and FM. It doesn't have any interference problems like the Silabs or HQCT units making it the perfect option for Car PC users. Click here for more information and to purchase.

Display and Stalk
My car has an LCD display at the top of the dashboard that the factory head unit connected to to display station information, etc. This display unit in turn connects to the steering wheel stalk. So far, I have worked out that it uses the I2C protocol to communicate and am working to make it so I can use the stalk to control things like volume, moving between tracks / stations, etc. I am also looking to have the display show station / track information so I can avoid having the main screen fold out all the time.

Future Projects
- A rear view camera that automatically shows when entering reverse.
- Parking sensors again automatically becoming active when entering reverse.
- As the slide out display I fitted covers certain dashboard buttons (rear window heater, door unlock for when the car automatically locks itself when driving, etc), I would like to be able to control these from within Centrafuse so am working on a simple input / output board.

I am a technology enthusiast living up in Carlisle, Cumbria in the UK and am the managing director of Its Elixir which sells Henna Hair Care Products and Ear Candles, Craig Brass Systems which creates and custom develops quality software and LonsdaleNET which delivers high speed wireless and fibre optic broadband in Cumbria.