OT: computer in a vehicle.

Fancy an ammunition box PC ? I have just built one for my site computer and for the 101 - its in a 9mm ammunition box, with an M10000 Nehemiah ITX motherboard, a slimline all in one CD-RW and DVD drive and 10 Gig hard drive (lying around at work) Runs SUsE linux 9.0 and Win 2000 if I have to.

Monitor is just a standard VGA at the moment, but I have a dead laptop with working Samsung LCD panel and I expect to get that working soon.

There is a video out connection, which would drive a tidgy TFT "TV" too.

Total cost (to me anyway) < 400 quid. Steve

Laptop I'd say, possibly with an external CD writer. Might be worth trying to find a s/h ruggedised one. Quite a few yachts use ruggedised laptops as glorified chart-plotters, so you might pick one up from a Yacht brokers or chandlery when the owner upgrades. That way its all tidy and in one box and won't mind the odd drips of water that inevitably come with a 1984 110!

Maybe you could ask on these forums to see if anyone knows of one going begging:

Failing that, an ordinary laptop, inverter and a sturdy plastic bag all mounted on 2 feet of foam rubber to absorb the shocks. You should have loads of money to buy one with as you don't have to shell out for all that Velvia and Provia anymore! ;-)

Have you managed to maintain the waterproof quality of the ammo box ?

I'm part way through building a similar setup for on-board navigation ( amongst other things) in my challenge prepared LR and would like to keep it waterproof by using glands for the cables and having the CD accessible by opening the lid. That way I don't have to worry about having the PC in the cab and it'll cope with DEEP water.

My main concern with waterproofing it is heat....

I assume you've used one of the DC to DC convertors to supply it's power from 12V ?

cheers

Dave W.

Yes, but unconnected at the moment - its for site use in my company in the main, not underwater in a landy 101 ! I don't need a "laptop" but I need a portable PC.

Trident Buccaneer connectors should work.

Stick with ITX and you barely need to bother, especially if you stay with laptop drives. Incidentally you can only wire them up with ATA 80 or 100 cables, not old 40 pin jobbies.

No, I am running it from an inverter in the landy, 240/110 in the field.

Steve

Twas Sat, 03 Apr 2004 17:50:02 +0100 when Mr.Nice. put finger to keyboard producing:

I've decided to use a desktop, in a custom built case (wood). now does a normal metal case act as some kind of shielding or will this be fine in a wooden case?

does anyone know what the current draw is on a PC and a 15 inch CRT monitor? (to price up an inverter).

and does anyone have any components spare? a p400 and board with USB, and a 20g HDD are my starting point.

-- Regards. Mark.(AKA, Mr.Nice.) ___________________________________________________________ "To know the character of a man, give him anonymity" - Mr.Nice.

mrniceATmrnice.me.uk 110 CSW 2.5(na)D___________________________________________________________

Probably more than 200W.

Steve

Don't bother with a PC or laptop.

Use a Smartdisk Flashtrax. I bought a 20GB one for £230 recently. If the built-in screen isn't big enough for you, plug a TFT video monitor into it (check CPC for reasonable prices). You can use a 5V regulated power adaptor (about £5 from CPC) to save the built-in rechargable battery. It connects via USB to the PC as a removable disk drive. Leave the CD writing until you get home.

I shoot RAW format on a Canon 300D and can get over 3,000 images on the 20GB version and you can get bigger ones if you want. It's also got the advantage that you can slip it in you pocket or camera bag when you're out of the vehicle.

Twas Sat, 3 Apr 2004 22:48:38 +0100 when "Steve Morgan" put finger to keyboard producing:

Now that, sir is a stirling idea.

*much tipping of hat* you shoot prefessionally BTW?

-- Regards. Mark.(AKA, Mr.Nice.) ___________________________________________________________ "To know the character of a man, give him anonymity" - Mr.Nice.

mrniceATmrnice.me.uk 110 CSW 2.5(na)D___________________________________________________________

I think I'll try and stay clear of mains for my use :-)

Does your CPU have a cooling fan or is it one of those that doesn't use one ?

cheers

Dave W.

No, I'm just a keen amateur who compensates for limited talent with expensive equipment :-)

AFAIK, the VIA Eden based ITX boards don't need cooling fans - in free air at least an EPIA 5 runs around 35-40 deg C.

Steve

There are cases which will take one of those boards, and use the case as a heat-sink. I don't know if there are any waterproof/ruggedised cases, but they usually depend on an external mains adaptor. I don't know if the supply is single-voltage, but portable-PC tech is commonly used for the drives.

Trouble is, you still have the standard set of external ports on-board. You would have a problem waterproofing them.

An ammo box is about as ruggedised and as waterproof as you can get ( assuming it still has it's sealing rubber and it hasn't got any holes in it).

12V psu boards are available that will deliver full ATX spec outputs from a 10V-28V source for under 30 quid.

The ammo box is big enough to completely enclose the mother board and all it's ports. The input/output cables would have to go through IP67 glands.

I'm thinking about using an RF USB link at the moment so the only external cabling would be the supply +ve from the vehicle, an RF aerial and a video lead.... possibly with a couple of audio cables for speakers. I can probably arrange things so that all those feeds go through a single multi-core cable for ease of sealing.

The CD/DVD player would be mounted so that you open the lid of the ammo box to access it.

Obviously waterproof = no external air flow which is why I was asking about cooling...

cheers

Dave W.

This would be a bit of a problem. If you were a real enthusiast you could plumb it into the aircon. But does the ammo box need to be totally waterproof? How about keeping the lid open when using the computer, and turning the computer off and shutting the lid when you drove through a lake?

David

Mine has. Does anyone know how you get it back in ?

FULL ATX ? All 200-300W of it ??? 25 A at 12 V ?

You can get USB connectors from Farnell which are waterproof USB and CAT5.

That would be neat, though some of this lot are very highfrequency cables, and with limited drive from the PC. Steve

Not sure what could be acheived by attaching the ammo box to the vent flaps ??? :-)

The primary use of the computer is for navigation in challenge competitions. It will be linked to the navigators GPS and allow quick input of grid references via a remote keypad. The colour (dash mounted) screen will allow an overlay view of scanned 25000:1 and 50000:1 OS maps to be superimposed with waypoint, route and next waypoint information. Turning it off isn't really an option as we can't afford the time taken to reboot every time we go through some water or mud. Relying on someone in the team to close the lid every time we go through some water is asking for trouble... it'd be nice to finish a competition with a full compliment of shackles !

I think the solution is to use one of the slowest fanless motherboards and give it a go. Hopefully it'll have a thermal shutdown if it does overheat !

I had thought about rigging up an air flow using an external pump with inlet and exhauset at roof level but it may not be an issue anyway.

cheers

Dave W.

No, a PSU that's scaled down to suit the maximum requirements of a single hard disk, a CD drive and a motherboard - about 80-90W, 8-10A allowing for losses.

Probably this one in my case...

with one of these motherboards....

I'll look into those.... an external USB port on the box rather than using a USB extender cable would be nice.

Maximum distance of cable would be the video, as long as I use individually screened pairs it'd be alright. Alternatively I could mount waterproof multiways on the box with internal jumper wires.

cheers

Dave W.

Ahah, it makes sense now.

How about this: get a laptop and bolt it to the inside roof, so it's upside down. It's then well out of harm's way (or at least, if it gets wet, you'll already have drowned). You don't need to worry about waterproofing the cabling etc. You don't have to worry about second batteries (to avoid rebooting when the starter kicks in) either.

You have the added bonus that you can drop the screen down and use it as an in-car DVD player with a huge screen, with software like PivotPro to turn the image the right way round.

In fact, that's such a good idea, I think I'll do it myself :)

David