Thread: Car-puter / GPS DIY Build-up

The short story

I now have all the bits I need for my Carputer, (I think) so I will get it started, soon………………ish

Pics will accompany the build and fitting.


Long Story
This is a long post, and you will probably notice that I have added to it over time. Basically it's what I acquired/bought and some reasoning behind it.


I posted this here for 3 reasons.
It may help someone else planning this sort of thing.
I may give me a bit of motivation to get it started.
I’m really bored at work and if I type it looks like I’m working at least ;-)


What I want:
A “carputer” that can be used mainly for GPS but also play mp3’s.
Yes I know I can just go buy a NavMan and have it all already done but PC’s are just so much more versatile. I want to be able to play MP3’s, store photos & video clips, have the RAVE CD and other techie manuals. Possibly watch a movie or two on long drives, (no me the wife) I’m also toying with the idea of a reversing camera in the future. Maybe even add a TV and/or radio receiver, try doing all that on a Navman ;-)

Cost:
As little as possible ;-)
Before you say, “just go buy a laptop”, I have one but I do not want a new laptop exposed to the sort of environment an off roader is exposed to.

What it should be:
As small and low wattage as possible to save on the batteries and leg/luggage space.
As rugged as possible to cope with the dust and knocks a carputer in an off roader will get.

The main components I will need are:
Donor computer, (Motherboard & cpu, video, audio, ram, harddrive, cd/dvd drive, Mouse & Keyboard)
Suitable power supply
LCD screen
Case
GPS receiver
GPS software & Maps

Motherboard:
The donor computer was the easiest to sort out I had a couple of spares in the garage.
The one I selected was is an Intel motherboard with onboard Video and an 800-900 PIII processor. The motherboard while not exactly a power house will be ample for playing MP3’s and a GPS system. These applications aren’t exactly CPU intensive. Also the slower CPU speed means less cooling will be required and thus less wattage is used and cooler CPU is useful for the back of a Rangie on a 35+ day.
I wanted a motherboard with as much “onboard” as I could get to keep the size small. This one has onboard audio and video so that’s a good start. I don’t want to use any PCI cards if I can help it so the overall height of the case will only be the height of the motherboard plus the cpu + heatsink + fan. That’s the theory anyway. I’m not interested in a network port. Although it might be handy, once the system is setup and fully patched the only updates it will need will be MP3’s I hope. These can be added using a USB drive.

Video
Shared onboard video, not a lot to say really other than I will need an LCD monitor that will accept a 15pin VGA input. I could have beefed up the video but at the cost of increasing the case size and internal heat. That and it’s really not necessary for the applications it will run.

Audio
The onboard sound is stereo and other than it possibly needing a bit of amplification before it gets to the existing Rangie speakers it should suffice. Once it’s finished I’ll try it out and if it needs it I’ll install a small amp.

Ram
The motherboard has x4 SDRam slots so I put in x1 512MB module.
I selected 512mb of ram as this should be more than sufficient ram for the task and two 256 modules would draw approximately twice the power of one 512MB module. I know we are only talking about a few watts here and there but they will all add up.

Hard Drive
In trying to keep the case as small as I can, (and I just happened to have one) I decided to use a HDD from a laptop. The internals of a laptop HDD are designed slightly differently to desktop drives and will stand up to more knocks and bumps. I bought a laptop to desktop (IDE)adapter from ebay which on connection didn’t work !
After testing the drive at work I found it was the actual drive that was buggered not the adapter. Oh well I would have to use a standard 3.5 HDD.
I didn’t really want to use the desktop HDD but as I only had one laptop HDD it will have to, (what do your mean I’m too tight to buy a new one!).
I will mount the HDD horizontally above the motherboard as close as I can without danger of shorting circuits. This will make the case long and wide but not very deep. I intend to mount the case in the Rangie vertically but not too sure where yet.
When the case is mounted vertically this inturn will make the HDD vertical as well.
This will help to prevent the HDD heads smashing on the platter while it is reading/writing data if there are any hard bumps.
I am also going to try and mount the drive on some sort of padding or spring to dampen any knocks as, excluding fans this is the only moving part in my carputer.
Bit of an update, a mate gave me a small (12GB laptop HDD so I can use that J

CD/DVD drive
Probably won’t bother, I might put an external IDE connection to the case or just unscrew the top if I need to connect an additional drive, (temporarily).
.

Keyboard & Mouse
I will probably take a keyboard and mouse along for the ride but not connected. Eventually I may get one of those foldable rubber keyboards and a wireless mouse if I find I need to use them often but hopefully not.

Power supply
I do have a 600w inverter, (I did have I just sold it) that would power the computer and any suitable monitor without any problems. An inverter has it’s advantages and disadvantages. Advantages: Easy to install and you can run any other appliances from it you need.
Disadvantages: Mostly the thought of having a live 240v power supply in your vehicle and probably under one of the seats hmm. The other is that, (I have heard) an inverter constantly draws power whether used or not and is not as efficient in it’s use of power. I would be converting 12DC via the inverter to 240vAC, then a transformer from 240v to something more suitable for the carputer or use it’s existing PSU which would increase the size of the carputer case and cause more heat. These conversions would decrease the available battery power.
The alternatives would be to find suitable 12v transformer from a laptop and do some surgery on it or buy, (yes, buy) a purpose made 12v PSU for a motherboard.

I checked out ebay and bought a small PSU board for about $45. Damn I had to spend money on it!
When I bought the PSU and tested it I found that the motherboard components fouled the components on the PSU. Not a good thing. I bought an ATX motherboard socket extension cable. Money again ! $8 This moved the PSU away from the motherboard and possible shorts, (not mine, the electrical type).

I have just thought that the mini-psu I bought will have a maximum watts out so I will have to ensure I don’t exceed it. I have been thinking that I could run just the motherboard/CPU from the mini-psu and doctor the other innards, (fans/HDD) to run straight from the battery. I’m not sure how reliable that would make it but I might give it a go.

LCD Screen
There are loads of LCD screens available. They seem to be vastly cheaper on ebay than local suppliers. I want one that has a minimum of 800x600 resolution and about 7” to 8” screen.

The optimum screen for me would be a 800x600 resolution on an 8” or more touch screen that natively runs on 12volts and has a backing plate for fitting to the dash, but I’ll just have to wait and see what the E-bay gods throw my way.

He He Look what they threw; I collected my 8” LCD screen from the post office this morning, ($207 inc postage)

Specs:
Touch Screen 800x600 native resolution he he he up to 1024x768
x1 VGA and x1 RCA video ports
Built in speaker
Ball & Socket base stand/mount, (it’s part plastic not sure if I should use it?)
Native 12v and only 10w power consumption
Oh yer and it has a remote control, Why??


GPS receiver
There seems to be two different connections wired and blue tooth.
As I don’t yet know where I am going to mount the carputer or the GPS receiver in the Rangie or in relation to each other I don’t know which to get. The longer a USB cable is the crappier the connection gets especially if your device is USB powered.

I bought a wireless bluetooth GPS receiver from ebay, (approx $100 arghhh) so it can be mounted wherever is best on the day. It has a magnetic base which isn’t a lot of use but it may stop it sliding around too much. I also bought a USB bluetooth receiver from ebay for a few bucks. I will hardwire this directly to a USB port on the motherboard inside the case as I don’t want it sticking out from the back of the case. It’s quite small, about the size of your little finger.

The GPS receiver can be 12v powered us an inbuilt rechargeable battery or inbuilt solar power. I hope it will last a full day without a recharge. I tested the receiver for sensitivity in the house with my laptop. It works great. I took the receiver in another room inside the house and it still worked. It doesn’t look like connectivity is going to be a problem.

Case
I am trying to decide to either build a custom case, (more hassle) or just buy the smallest case I can find and mod it to fit the stuff I want to cram into it.
Still thinking………


GPS software
I chose and have bought OziExplorer it seems to be one of the defacto GPS systems in Australia. The bits I like are that you can add your own custom maps and buy the map “packs” as well as download them if you have the time. So maps are not an issue and can be had for free.
I already have a PDA running TomTom GPS software for the car which works great around the streets and this can get me where I’m going off road if needed with spoken directions but Ozi picks up where the Gazetted roads GPS systems stop. These are certainly, (for me) the best of both worlds TomTom on road excels, off road Ozi is great.

GPS maps
I have quite a lot of WA maps and some of other states too but as I mentioned before they can be downloaded as needed for free before you plan to travel in a particular area so that’s what I’ll do.

Brand new 1.7ghz laptops - currently advertised for $450 after cashback advertised in the junkmail - why built your own carputer? I just drove from Newcastle to Canberra with the laptop sitting in the drivers door pocket - gives access to to the DVD - the GPS works a treat - I have a DVD/MP3 player car radio (I have my MP3s on 9.5g DVDs) but the laptop can plug into the front of this like an MP3 player.

It would seem one of these cheap laptops with a $50 power supply - a $200 7" screen will work just as well as what you are doing, at about the same price but a lot less mucking around.

But then I guess half the fun is building what you are building.

Garry