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Outdoor Computer Cases? 192

danci asks: "I'm building a wireless network in a local community using Wavelan/IEEE cards. I'd like to avoid purchasing Wavelan access point so I'll try to use Linux instead. So I'd like to build some rather small but robust machines that should be able to survive summer, winter, snow, rain and most other weather conditions while being mounted on the antenna mast (or at least as near as possible - cable length heavily decreases range). So I guess what I wanna know is whether there are any weather proof, computer (PC) cases available out there. Or some other, low-cost solution (don't want to build a house around all that)." This would be too cool. Just imagine, a series of computers mounted to telephone poles with wireless network cards...
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Outdoor Computer Chassis?

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  • Look at some of the sailing/cruising magazines (some have web sites). There are several makers of hermetically sealed computers to keep out the salt-filled air - which is deadly. I'm not sure they are waterproof however ....
  • Hmm. Idont know. An outdoor case while seemigly attractive... doesent seem incredibly feaible. You would need a compleatly sealed case and power supply and all that fun stuff. But even beyond that, wireless technologies are still painfully slow compared to what most land lines offer. I suppose you could encase the entire thing in a plastic box... and run some conduit down the pole for power cabling... but you probably thought of that already. You could ask wavelan too, although they probably wouldn't tell you. In any case, i personally think its kind of like shooting yourself in the foot. I also dont have a tremendous knowledge about wireless networking. If you can seal the case, and make it small enough to fit on the pole though, by all means let linux rule and the peons drool.-n-rs-
  • by jellicle ( 29746 ) on Tuesday December 21, 1999 @05:10AM (#1456431) Homepage
    I'm thinking something along the lines of this:


    People have already a put a lot of effort into building weather-proof, battery- and solar-powered cases which can hang on telephone poles for applications such as environmental monitoring. They hang them along highways (some of them have a hook on top to hang from a telephone pole and come with a big forked stick to facilitate getting them down from the pole), then you come back in a month to check what sort of pollution is being produced. Don't reinvent the wheel here, talk to one of those companies and see about getting some cases, maybe with power supplies included but without the environmental equipment.
    Michael Sims-michael at slashdot.org
  • by GC ( 19160 )
    Just imagine, a series of computers mounted to telephone poles with wireless network cards...

    And a nice pick for any passing burglar :)

    It would be way-cool, but then why not use the telephone wires...?
  • Well, surely if its hermetically sealed it is waterproof. Nothing gets in or out. IF it keeps air out I'd be suprised if it doesn't do the same to water.

  • by Zurk ( 37028 )
    just wrap the things in plastic - put a plastic bag and wrapping to fully enclose the case and get waterproof cables (should be available in most outdoor stores). Also try and use a chip that runs cool..something like a cyrix MII with power saving modes and you should be ok. Getting a ruggedised laptop is another way or a mil spec machine.
  • Take a look at Dolch. They make some pretty tough machines (some are even bulletproof)

  • You're asking for a lot... Not only do you want to bring a PC outside, you want to mount it on an antenna mast? It's a lightning magnet. Even without lightning strikes, you're dealing with a lot of static electricity. If that doesn't kill your PC, chances are the variances in temperature and humidity would.

    Having said that, it still sounds cool.

    I have to wonder though, if your only concern is cable length, why don't you just install a signal repeater or cable driver of some kind outside and bring the PC indoors somewhere?

    A cable driver is a lot less expensive than a PC... =)

  • How do you protect a case from the elements while still providing enough air circulation to keep the processors happy?

    That would be bad if you spent all the money on sealing a case only to have the processor burn up on you in the summer heat.
  • You're right, of course, but I was thinking more along the lines of the external connectors and any effect water may have on them.
  • By sealing it up, you're not letting much air pass through, and the thing will eventually heat up (depending on how big the case is). Especially if it's outside and you don't live in Alaska. I don't think that succeeding in this venture of yours will be cheap. I can't imagine that the boat equipment that someone mentioned before runs so fast that it generates a lot of heat... for this to be cheap/feasible you will probably be stuck with sealing up a slow computer.
  • If it can keep out saltfilled air, it can definately keep out water. It's probably not even just the salt that is the problem in a marine environment, but the combination of salt and water. Almost nothing is as good as those two together in corroding just about anything that will corrode in under a week. But once you get salt in, you have a problem... the stuff is incredibly hygroscopic (It attracts water like fresh dogshit attracts flies). Also, sea-salt is not a pure substance by far, but a mixture, and several of the "salt" crystals will contain quite a bit of water in their lattice. to cut it short: in a marine environment, salt equals moisture, and the quick demise of all computers.

  • The problem with installing a signal repeater is mostly that they don't work on recieve lines.

    The length of the cable in question has a direct relationship to how well a signal can be recieved by the tranciever assembly.

    Untill that signal is picked up there can not be any use of signal repeaters.

    also a signal repeater will
    1) slow down the data rate (not much but some)
    2) introduce more noise in the signal for each repeater used.

  • World's Toughest Computer Case by Pelican This case is unbelievable -- watertight, airtight, crushproof, dustproof, shock resistant, and attractive enough to use as an everyday attache. Includes a lid organizer that, like a regular briefcase, holds papers, pens, cell phone, etc. There's... www.landfallnav.com Might not exactly be what you ae looking for.
  • One of the PC/104 companies makes a line of boards that come with aluminum frames. You just stack up a p/s, m/b, and whatever periperals you want, and you end up with an aluminum cube intended to be bolted into an industrial setting.

    I looked at these with the idea of setting one up by my pool so as to have music, but the cost for non-mass-market stuff like this tends to be prohibitive. It's also not clear that you can get a PC/104 format wireless ethernet board.

    Grant Taylor [picante.com]

  • The two primary resources I'd recommend looking into are:

    - Embedded Computing [embedded.com]
    - ARRL [arrl.org]
    - RAC [www.rac.ca]

    ...those are just some starting points. Embedded computing applications have the hardware designed for rugged environments, and amateur radio is a handy technical resource for do-it-yourself electronics. Remote relay stations are the norm, not to mention other extremes [amsat.org].

    Search engines are your friends, particularly Google [google.com].

    de VE3SLG
  • by Cheerio Boy ( 82178 ) on Tuesday December 21, 1999 @05:23AM (#1456447) Homepage Journal
    Here's an idea - use one of the embedded versions of Linux to run an ultra-small server - (/. has run several articles on this including one about the Worlds Smallest Server) - and use a standard industrial box to enclose the whole thing. Digi-Key or Resource Electronics or just about anybody has those.

    Since we're talking about a wireless network you're probably not going to get off cheap but you can almost certainly manage to produce something stable and with a long up-time that's affordable.
  • You won't just need a weatherproof case, you'll need a computer which can take the temperature extremes.

    No desktop type components are going to handle outdoor temperatures in any but the most mild climates (read, SEATTLE). Working with pole-mounted equipment design myself, I was surprised to find that even military-grade components may not be up to the task.

    You'll at least need mil-spec components for the harsh environment you're describing.

  • by Anonymous Coward
    Check out the embedded computing folks... They've been putting together tiny PCs for years. Check out stuff in the PC104 form factor... should be fairly easy to find a system and ruggedized case, because they're used a lot in avionics, industrial control, and a bazillion other "non-tradional" roles.

    Problems you'll run into are weather fluctuations (hot in the summer, cold in the winter), humidity/condensate, direct sunlight does nasty things to some plastics, birds, squirrels (and other rodents) like to chew on cables, the list goes on and on.

    And just a thought to keep in mind as you work on this... Lightning strikes really, really suck. Especially if what gets hit is hooked to your home network with a cable. And even more so if it's plugged into the same electrical circuit as your other household electronics.
  • You really should look into going to some Military Surplus sales (that is if you are in the US). When I was in the Military we had some old field computers called YUK's. Which is an acronym for something or the other. They were just 386 and 486 at the time but damn were they sturdy. If you could get your hands on one of them you could try to replace the mother board and CPU with a faster one and go from there. They are very distinctive computeres, they are all green and come in cases about 3 feet square. The case opens up and the computer sits inside with about a foot of padding on all sides.
  • by Tau Zero ( 75868 ) on Tuesday December 21, 1999 @05:27AM (#1456452) Journal
    I'm not sure why you need to put the computer out on the mast. Care to explain that (other than it being cheaper to have one case than two cases), danci?

    My point: GHz RF has high losses in cables, but typical data rates have much more managable losses. If you can split the RF sections from the rest of the system, you can still put the electronics in a temperature-controlled environment while keeping the antenna cable short. (This assumes that the RF section will function under temperature extremes, which it may not. Test things in an environment chamber before you rely on them.)

    I'm not familiar with Wavelan cards, but I'm going to make a guess here that they have both the digital and the RF sections on a single internal bus card and you don't have the option of splitting the system. In this case I would examine better transmission lines. One old technology I'm aware of is Goubeau line (I think that spelling is correct, Georg Goubeau is listed as being on the faculty at the University of Jena in Germany, specializing in the generation and propagation of EM waves). Goubeau line uses a pair of "launchers" to take a signal propagating on a coaxial cable and allow it to travel in the neighborhood of a bare wire; this nearly eliminates dielectric losses. While you'd need coax for any runs indoors, you could use Goubeau line to go from the outside wall wall to the top of your mast. I'd suggest using a flexible standoff/tensioner on the mast to keep the wire taut, and avoid the use of spacers. If you have a tower, I'd try running the line right up the middle.

    Niggling issues like dealing with icing always rear their ugly heads. You may wish to design your antenna so that it is always at DC ground and have a big honking transformer to throw some low-voltage AC up and down your wire. This would let you melt ice and snow off it. If the Wavelan card provides signal-quality reporting you could even have your computer operate the heater as needed.


  • There are 486's in obit (periodically.) They get hit by much worse things and still function. As long as it's not grounded, lightening isn't a big problem -- you've obviously never seen a demonstration of a Farrade cage.

    HOWEVER, I'm not suggesting one take a desktop PC and strap it to the mast. What you need is an industrial computer -- computers designed for environments where humans could not survive (for long.) Those things are not cheap.

    The best (cheapest) bet is single board computer (SBC.) Maybe even one of the "computer on a SIMM" creatures assuming you can attach the wavelan to it, etc.
  • First, standard computer board will not tolerated the temperature difference and all the static charge caused by environmental factors. You need an industrial strenght board to sustain outside conditions.

    Second, the best 'cheap' solution would be to use a laptop computer put in a multi-layer box (multiple layer will give you better insulation). You have to find a way to let the air flow at a good rate while keeping dust, water, snow, etc outside.

    Why the latop is a good 'cheap' solution, they are made to sustain high temperature change (at least when they are off), they can systain a certain amount of humidity and they are designed to consume less power and release less heat.
  • by Anonymous Coward
    But cable length is only an issue with cable,no Fiber. Like one of the other posters said, dont reinvent the wheel if your distances are short,say less than a mile, why not run fiber optic. If not why look to the design of Phone switches. their water proof and similer in design to what you are looking for
  • Why stick a computer on the mast? BreezeCom makes radio-to-ethernet boxes you can hang on the mast. Then it's just a matter of pulling 10bT to the computer up to 200m away.

    I've used these things before and they work great. I bridged the ethernet between two buildings 4miles apart at 1Mb/s -- of course there was a long range directional antenna at both ends.
  • but Breezecom has some products you might want to look at. I've never used these specific ones, but I love Breecom's stuff. You DID say low cost, which this not, but some things to do have to pay for, and having a PC out in the elements isnt going to be easy. Check out http://www.breezecom.com/Products/Antennas/ant_acc ess_overview.htm and look at the ODB1 box and the PI-CAT5. The PI-CAT5 actually runs the 5 volts it needs to run the access point over the cat 5 as well as the data. This makes the distance you can run the cables much much longer.
  • by Anonymous Coward on Tuesday December 21, 1999 @05:34AM (#1456461)
    duct tape. Lotsa duct tape.
  • by BobTheTomato ( 121482 ) on Tuesday December 21, 1999 @05:34AM (#1456462)
    Finding all weather sealed computer cases are the least of your concerns. They are fairly easy to find, especially if you decide to use a SBC instead of a traditional AT or ATX motherboard. (The slot covers are very difficult to seal on AT/ATX). Do a web search on SBC to find a plethora of single board computer manufacturers. You will probably want to get something in a PC/104+ form factor instead of a backplane based form factor.

    Look into the D38999 series of mil-spec connectors for bringing connections out of the box.


    Don't forget to chose your components wisely. Get industrial temperature range (-40 to 80C) components where possible, and especially if you intend to use a traditional hard drive. A flash drive is better if you can afford it. Spinning up a mechanical drive when it is too cold can destroy it.

    Finally, put some thought into heat dissapation. For outdoor applications it is best to have a sealed box, which means no cooling fans. If you can, choose a low power consumption motherboard. (say a recent 486 class machine.) By all means, get a case that has large cooling fins on it, as that is the ONLY way that you'll ever get heat out of the box.

    Good luck.
  • by G27 Radio ( 78394 ) on Tuesday December 21, 1999 @05:39AM (#1456465)
    Environmental Specs:

    Operating Temperature: 0 to 50 degrees C (32 to 122 deg. F)
    Non-operating Temperature: 0 to 60 degrees C (32 to 140 deg. F)
    Shipping Temperature: -40 to 60 degrees C (-40 to 140 deg. F)
    Relative Humidity: 5 to 95% non-condensing
    Wet Bulb: 29.4 degrees C (85 deg. F)
    Altitude (operating): 0 to 7000 feet (0 to 2134 meters)
    (non-operating): 0 to 15000 feet (0 to 4575 meters)
    Electrical - 100-125VAC and 200-245VAC switchable
    BTU Output (as-shipped): 200 BTU/hour
    (maximum config.): 1417 BTU/hour)
    Shock: 30G, 3ms duration
    Vibration: 0.67G RMS random from 5Hz to 500Hz
    Particulate Protection: Dust and dripping water resistant -

    ...additional info here...there are also different units available... [cutler-computer.com]

    We used to use a similar types of machines as data collection units for slot machines. The PC's ran 24/7, year in and year out, in poorly ventilated cabinets in an incredibly dusty and dirty area--no moisture to deal with though... Very reliable. The question is will the machine generate enough BTU's (in the spec) to keep it warm during the winter...and will it stay cool enough during the summer.
  • Get an external electrical box. You know, the kind you'd hang on the outside of your house. They are waterproof and have all the cable ins and outs that you would ever need. Since they are sold in high-volume, they are less expensive than something built to milspec or specifically designed for computers.

    Of course, the electrical boxes probably won't hold a generic PC without a bit of modification. Since the box will be headless and without floppy drives, keyboard, etc., you're probably better off just mounting the motherboard in the unit on its own.

    That said, your greatest concern is going to be lightening, not water. If you wire the boxes with copper, you're making it an easy run from the mast to the wiring closet. For external applications, you *MUST* use fiber as it does not conduct electricity. (This, of couse, assumes that you don't want to fry your networking hardware. If you're okay with that, copper works great and is less expensive.)


  • These guys build PPC supercomputers. They make some pretty sweet machines. These ones are especially interesting.

    Sky Rugged Computers [sky.com]

    You may want ot just give them a call and see what they do?

    Anyways, sweet machines.....

  • by reaper ( 10065 ) on Tuesday December 21, 1999 @05:43AM (#1456469) Homepage Journal

    I think I can help you.

    I'm currently working on an outdoor pc system designed to basically work in man holes (15 feet fully submersible for prolonged periods, dust/water proof). What you need (and this is only one solution, but it is cheap) is a single board computer, power supply, NEMA 4 rated enclosure, and applicable glands to bring the wires out. Basically you mount everything inside your box (generally made from fiberglass, aluminum or some type of plastic), install the glands (watertight cable feed throughs), and mount this baby.

    JumpTec [jumptec.com] has some of the systems you could use, and more importantly has an IDE flash disk that makes all this easy to do without a hard disk. Also Win Systems [winsystems.com] is a pretty popular place to get PC/104 embedded systems.

    As for the case, Hoffman [hoffmanonline.com] has all the enclosures you could ever need (unless you're working in man holes).

    Some people have recomended Dolche, but I'd avoid them as they are way expensive. More useful for interactive systems.

    good luck

  • This can easily be done in my opinion. Build the case from plexy glass or other plastic materials....make sure the power supply is inside along with some copper tubing for your cooling system as you are going to need to liquid cool if you aren't going to have air flow. Next, you need to bring the cooling tubes out of the case and build a radiator with some fans blowing across it....this part doesn't have to be very protected from the elements....then paint the thing with liquid rubber of sorts to seal it. Of course, an easier solution would be to go to a company like Fibertron....they sell several outdoor cabinets used for fiber optics equipment which are sealed from the elements. Another option would be get a tube that the computer can fit in (would have to be rather big, y/n? hehe), cap the top and mount the board at the top...run all cables out the bottom and give a few feet of extra space at the bottom...chances that the elements easily find their way up that is much less and its a very inexpensive route. -Dan Guisinger
  • Putting just the net card on the post probably wouldn't work very well (Yes, that's because of noise on the bus).

    However, if the base station computer was inside and had an Ethernet adapter (10base2 would be best, but 10baseT would work too), then a wireless Ethernet bridge could be mounted on the pole with a cable running to the inside.
  • by SEWilco ( 27983 ) on Tuesday December 21, 1999 @05:44AM (#1456472) Journal
    I think what you want are called "NEMA enclosures" [nema.org] in the industrial environment. Sealed boxes. You pick a level [protech1.com] suitable for an outdoor wet/freezing location.

    Parvus has several [parvus.com] for the PC/104 [controlled.com] size, as does Tri-M [emjembedded.com]. Digital has some [digital.com] for their products.

    There are plenty of generic NEMA enclosures available, up to walk-in size.

    Remember you may need a heater or cooler. There are standalone devices, although I also have seen one PC/104 card with thermostats [rtdusa.com].

  • A cable driver is a lot less expensive than a PC... =)
    Unfortunately, a remote power RF amplifier with receving preamplifier and automatic T/R switch isn't quite as simple, or as available, as a cable driver.
  • by Anonymous Coward
    I've never tried putting it in direct rain, but we used to install computers into Sawmills and we would seal them in big tupperware containers...
  • OK, if you count the time to build the enclosure, you are probably not saving any money unless you are doing LOTS of em.

    Maybe you need to think of something other than an "enclosure". What you want is a box that keeps the elements off your computer. Something like a very small shed with a pitched roof.

    I would suggest a small dog house would be about the right size, and relatively cheap too. There are some very cheap plastic ones on the market but they'd be harder to modify to make secure. Something like this [blythewoodworks.com] might be good, and fairly attractive. Just get a piece of plywood and screw it down over the door. The main problem is that these are rather large, although this offers room for a UPS and a circuit breaker box.

    Of course, if you are planning on putting these on roofts or utility poles, this might be a little big and kind of ugly. Perhaps a large bird house [blythewoodworks.com]. Take a martin house, plug up all the holes, and use a sawzall to cut out the internal dividers. If you can scavenge used laptops or use something like a netwinder you can get down to a regular sized birdhouse. These would have the advantage of not being an eyesore. I would take some silicone caulk to the joints, however.
  • I don't know about weatherproof cases, however you did mention that you were not interested in using the Wavelan Access point. I have heard that the Apple Airport is compatible with 802.11 cards that use 2.4 GHz DSSS such as the Wavelan card. The Appple airport [apple.com] only costs $300 and includes a built in modem. I have received the Airport and I have ordered the Wavelan cards and am waiting for them to come in to test it out. The Airport does not allow HTTP configuration such as other access points and is only configurable by an Apple Computer AFAIK, however, the default configuration should be to assign IP addresses via DHCP so no configuration should be required as long as you have your network setup to use DHCP.

    Anyway the Wavelan cards should be in soon. Email me with your address and I'll let you know the status of my tests with the Wavlan cards.
  • Unfortunately marinized computers are horifically expensive. Expect to pay $3k-$4k US for a low end configuration. They actually make laptops look like a price performance bargain.

    I would also guess that marinized computers wouldn't fit the bill from a size and feature perspective either. If you're going to be putting something up on a pole you'll want it reasonably small. Most of the marinized systems I've seen are roughly the size of the old Compaq luggable (oops, I've dated myself.)

    I would expect a single board computer with a PCI adapter slot would be a better solution. You should be able to be readily mount this in a much smaller water proof container.

    The next issue to resolve would be the heat dispersion. Since you'll have no air circulation you'll have serious heat buildup problems.
  • The best part is if you went with the birdhouse idea, you could call your network "martin.net".

  • I would start by visiting my local planning office to see what sort of weather you can expect in your area. How much rain, snow, how hot, how cold and how long for each extreme.

    Then I would go to a building store and see what materials are there. For a computer case size object, its really cheap. In fact I would ask one of the guys there, since they would have a good idea of the weather extremes.

    Next I would worry about fan exhausts, power supply, lighting and animals making new homes. :)

  • I suppose that you could keep things cooler if you severely underclocked a fast CPU. But the minute you add a HDD, SCSI adapter, whatever, things start to heat up again. And then ventilation/filtration is a problem.

    You might have to go with the "little house" concept: put an otherwise normal PC inside an outdoor enclosure made for that purpose. I'm thinking of the kind that they use for cellular equipment [electrorack.com]. But that ain't going to be cheap.


  • by PapaZit ( 33585 ) on Tuesday December 21, 1999 @05:54AM (#1456481)
    While saving a few bucks is admirable, the simple truth is that the wavelan access points were already designed to solve all of these problems and more.

    If you're doing something that's non-profit (or otherwise capable of generating good PR for Lucent), give them a call and see if you can get a discount.

    Otherwise, you're going to end up spending more money in the long-term on maintainence and replacement (like someone said, PCs on a phone pole would be a tempting theft target) that you would on the more expensive equipment.
  • Ah, Pelican makes cases for carring things, not putting them up on a pole somewhere...
    Accually I own four of them for my cameras, and yes, they are as good as they claim.
  • Putting a computer on the mast is not a great idea. Although it can be done, it costs quite a bit for a reliable solution.

    Depending on the frequency that the wavelan cards use, you can use something the microwave industry has used for decades: Waveguide. Basically a small duct with a transducer on one end that passes the signal through the waveguide on a shielded path. The waveguide is usually sized to the frequency of the transducer. Check some of the microwave ham radio pages out there. Waveguide is usually used in the 10ghz+ spectrum.

    Another approach is to use a mast mounted amplifier and pre-amplifier and use a short run of 50 ohm hardline. This is what a lot of ham radio users use for high performance antenna arrays in the uhf and microwave spectrum. Basically, you keep your computer in your home, and run a length of hardline to the mast mounted amp/preamp. The signal losses incurred by the cable are overrun by the mast mounted goodies. By doing this, you can mount your antenna directly to the amp/preamp and have no loss.

    Hope this helps!!
    runlevel0 has been reached...
  • by walnut ( 78312 ) on Tuesday December 21, 1999 @05:57AM (#1456484)
    We do a lot of utility work... in the sort of places no one really wants to think about (under New York City) We don't use traditional PCs, but we do use traditional pc parts (or at least traditional boards, usually with a few specailty boards. You could probably mount traditional pc parts (including the power supply) in one of the industrial cases [stahlin.com] we use - with the understanding of a couple of things... you can't run a hot processor, you have to have massive heat sinks and it takes a lot of testing and time to do it right... Think "low-end Linux box" not "quake machine."

    The cases (er cabinets) we buy are pretty darn rugged (i.e. waterproof, very heat resistant, pretty resistant to shock, etc).

    Now keep in mind, all external openings (for cords and etc) need to be tapped and all internal components need to be mounted in some way.

    Well here's a plug for the people we buy from:
    Contact information
    Stahlin Fiberglass (a Division of ROBROY Industries)
    Belding Division
    Belding, Michigan 48809

    Phone (616)794-0700

    However, that's just for a PC... I hadn't even considered a monitor. If you're expecting to put in a monitor and stuff like that... it gets a lot more expensive and difficult... now what you're talking is purchasing industrial grade PCs...

    Now you might be talking purchasing something from Xycom Automation [xycom.com]. But, most of these are also flat/touchscreens ($$cha-ching$$) and once again come preloaded with DOS/95/NT. I don't know about Linux drivers for those... However if you look around enough you will find a lot of machinery does run with some form of *NIX (to avoid the reliability problems of MS)

    Well, that's about the best I can do for you...

  • It would be particularly cool if you didn't seal up all of the holes, and let some birds share the house with your computer. I'm sure some feathered family would appreciate a bird house with central heating.

  • by pneurk ( 122261 ) on Tuesday December 21, 1999 @06:01AM (#1456486)

    We use the Super Duty laptop cases sold by cases-cases [cases-cases.com] to lug around our laptops in a marine environment. They definately hold up to abuse, and are comletely air/water tight.

    This would be more of a "you like, uhh, put your PC into this box thing" kind of a solution, and it will probably be a little bulky. You would still have to look at temperature, and lightning problems (plastic case tho, so it might be ok).

  • The idea of using marine systems is fine - but you might do better by checking the yellow pages (digital or tree-based) for companies that manufacture or sell equipment for food processing facilities. USDA-FSIS requires all equipment in the main processing areas in, for example, meat processinng plants to be completely washable, often using hot caustic solutions.

    Four years ago I worked for a major poultry producer and one of my projects was putting in case scaling and labeling systems in the plants. Instead of the expensive PLC based systems that everyone else pitched to us, our vendor had developed PC LAN based systems that were faster, cheaper, and more flexible. The trick was to use cheap PCs inside moderately expensive stainless steel (or in some cases fiberglass) boxes. There are established standards and components for these systems (the namees of which I cannot remember this morning) and you can get a lot of the pieces off the shelf. The external connectors were MILSPEC Amphenol type, and the monitor (when we needed it) was inside the box and visible through a sealed plexiglas window. The boxes had thick rubber seals and big stainless steel clips to keep them closed. They were not too small, so the air could circulate some, and the environment these were kept in varied from 27 to 40 degrees F.

    One of the neater components was the Dragon keyboard that was first developed for artillery control units - its a keyboard with a very thin sheet of flexible stainless steel over it which you press the keys through. Not something to code with all day . . .
  • Tupperware

    I use it whenever I don't have a case handy. Only problem is ventilation on those air tight burp-seal tops.
  • Well, I once had mice in a 3b2/400.

    As far as birds are concerned, I finished a loft over my garage to use as a computer room but didn't adequately seal the ventilation holes in my soffits. I got a family of starlings nesting in my insulation. The Dad found a way into my loft one day and shitted all over my keyboards, monitors and computers. I sealed up the inside hole, and would have let them stay, but after consulting with the local audobon, I learned that they would attract insects. I waited until I didn't hear the babies any more, and sealed the hole up and destoyed the nest.

    Unfortunately, the birds had had another brood and I discovered five chicks after I boarded up the hole and I had to drown them. Five starling chicks are no great loss to the world, but on the whole I'd have rather lived with the insects.

    I guess this is not entirely off topic, because if you put a computer outside, you'll have to provide ventilation, and if you provide anything with a hole of 3/4 of an inch or larger that is not coverd with a well secured metal mesh, you will get bats and birds nesting. Insects shouldn't be too much of a problem if you keep a fine mesh over the holes and don't allow the wood to rot.

  • Farrade cage

    Ok, you mentioned it, what is it, & where can I find more information?

    I did a search on Google, but it didn't come up with anything.

    Just from the context of the post I have an idea of what it might be, but I want to know for sure.

  • Go with mil-spec gear if possible. If you can't afford it or really want to do it yourself, heres some ideas.

    Get a sealed plastic case. Computer intended or not. If it isn't specifically for computers get it bigger than you need, and rig some shock absorbing pieces in. An idea I've seen is some military field computers have pieces of rubber in the 8 corners.

    Cut holes that are just barely big enough to let necesary(and only necasary) cables through. Seal them up with that clearish rubbery stuff(can't remember what its called). Electrical tape might work, but I wouldn't rely on it.

    Lightning is a big potential problem. Unless you have a lightning rod with a superconucting cable, lightning will kill your computer. Make sure the antenna has a ground attached, preferably above the cable connect, using the lowest resistance cable you can afford. This may cause the lightning to travel down that rather than into your computer. Still, find out the maximum jolt your computer can take, and get a fuse that blows out somewhere between 80% and 90% of that. You will still lose connectivity, but rather than having to replace the whole computer you will just have to replace the fuse.

    Everyone thinks cooling would be difficult. Not really. You may want to look into a water based cooling system. They can keep your CPU extremely cold. Condensation can be a problem though, be careful about that. And don't screw up putting it together. The result of a mistake setting up a computers water cooler is obvious. Another option is setting up a big fan and ducting air in through plastic or rubber tubes, or even PVC pipes. HAve a top one that blows cool air in and a fan in the bottom that sucks hot air out. Through ducting you can keep the case cooled and airtight/watertight. The hard drive could be a problem. Bad things can happen at low temperatures trying to get a motor running. Primarily, get the drive with the greatest temperature tolerance you can afford. And among your options there, get the one with the best g-force tolerance you can find. No matter what this thing will be taking some shocks especially in a storm. Turning off all powersave options, or at least the ones that relate to the hard drive, may help keep the hard drive from getting too cold.

    All in all an ambitious project... but certainly feasible.
  • how the hell do you get the Wavelan to work under RedHat 6.1???

    Check out the Wireless Lan HOWTO at : linux.grmbl.be/wlan/ [grmbl.be]

  • I would suggest talking to Kryo Tech. They have some low end cooling setups that would cover the temperature problems. www.kryotech.com Then all you would have to do is place the case inside a sealed, locking box. My question is, what are you gonna do for the Keyboard, mouse and monitor? Your users need to have access to the keyboard and mouse, I suppose you can put a plexi glass window on the front of the monitor. My main concern would be vandalism and theft. If you put 1500 dollars worth of computer equipment out on the side walk, it's gonna disapear.
  • OK, if you're a programmer, putting a computer on a mast sounds like a good idea. (Temperature will KILL it, BTW.) To an RF engineer, it sounds like what we really need here is a low noise amplifier/power amplifier combination. The LNA will reduce the noise-polluting (i.e., increased noise figure) effect of the long antenna cable, and the power amplifier will boost the transmitted power back up the Part 15 limit. This sounds like something Wavelan or other wireless LAN outfits should put together.
  • I worked with SCADA systems where we had to mount the computer within a metal cabinet with a hermetically sealed door (which was bolted down in, IIRC, 4 places).

    While these puppies can't be cheap, there must be a mass-market (or close to mass) considering that the cable companies and power companies need these.

    And, hey, my experiences were 20 years ago.

    These cabinets would've been big enough to handle PCs, BTW, though I'd worry about heat distribution (you're not gonna want to use a P-III, Athlon, Alpha or whatnot...).

    Of course, you could go into business building these puppies in such a way that the CPU heat-sinks directly to the case...

  • That's because he mis-spelled it. Think Michael Faraday, as in the guy after whom the farad is named.
  • There is a solution already done that is exactly what you are looking for, but it may be a higher cost than you are expecting. The company where I work, Intermec, makes wireless networking products for manufacturers and warehouses primarily. We have a product known as the Universal Access Point that was designed and tested for extreme environments. These access points can now use Lucent 802.11 radios. You can check out the specs and get more information at: http://www.intermec.com
  • My (scuba) diving club has given up on "waterproof" electrical hardware (we're talking radios, GPSs, etc) for use on our inflatables because most of it just isn't. Instead, we now buy non-waterproof gear and keep it in sealed (big plastic clamp, nothing wimpy) transparent bags.

    My point is that you can probably make it waterproof fairly simply after you've packaged it all up - you don't necessarily need the case to be environment-proof.

    The "bag" idea also means it's easier to replace damaged housings; they'll get broken whatever they're made of.


  • People keep talking about problems with heat dissipation. One possible solution to this might be to submerge the entire computer in mineral spirits. I saw a picture of a computer that was set up this way once, in order to provide cooling for overclocking (sorry, can't find the URL, but search Ars Technica [arstechnica.com] for a link). Mineral spirits are nonconducting, and have been used in electrical transformers. If you put the computer in a ridged metal box, you should get okay heat transference from the box to the outside. You could even put heat sinks on the outside of the box if need be.

    I don't knwo what this would do for other environmental issues like cold or moisture.

    I have no idea if this would work, but I thought it might be helpful, and it shouldn't be too expensive.

  • Here's the URLs I should have provided in the first place:

    http://slashdot.org/articles/99/07/31/1654210.sh tml

    and my favorite:


    (Pardon me for not making them links - I'm hadicapped at work [drum roll] I use Microsoft.)

  • I've got a NEMA enclosure with a 40 Mhz. 486, hard disk running some serial devices. It's mounted on a telephone pole and has run reliably for years. The only failure I've had was the power supply and the CMOS battery. We built a sheet metal "shade" for the enclosure but in 100 F heat the inside temperature never went above 140 and it's never failed due to cold. It is in Northern New Mexico so it gets a pretty wide range of temperatures.

    As for modern equipment, a lightly loaded AMD k6-2 with a heat sink will probably do the job forever; just don't build any kernels on the damn thing during a heat wave.
  • The problem with that is noise and control. To keep from swamping your receiver with noise, you may have to bias your power amplifier off when not sending. Then your problem is to get the thing on quickly enough when it's time to transmit. If you can't get your amplifier re-biased and operating fast enough to get the packet preamble on the air (or worse, switch on abruptly and cause splatter) you'll have problems getting receivers to recognize your packets. Getting these things to work as a system can be a real hassle, and there are a lot of details that have to be just right.
  • Because you want to have internet access from your laptop without dragging a cord after you?


  • You *will* need at least one conductive heater per box, they won't survive winter without them, (the heaters prevent internal condensation)
    As for casings, RS Components sell rated-seal enclosures for (fairly) reasonable prices, but at least you get a warranty for any leaks :)

    otc: Wouldn't you be better off using line of sight optical networking? - is that possible?
  • Farraday Cage. The bags that PC components come in work on this principle. The static collects on the outside of the bag and your static sensitive components are nice and unstaticy inside.
  • I don't know what kind of budget you have to keep to, but yachtsoft.com has "marinized" laptops. Their Argonaut can take having water poured directly on the keyboard. They are compact and rugged, yet still have the functionality of a real computer.
  • Get a catalog from Graingers or similar - look at the cases made by Hoffman and their competition. Specifically look at the NEMA 4 rated boxes... those will survive nasty conditions. I built boxes that did essentially what you describe and they lived for years on power poles.

    Note: you have to be concerned about heat, since if you add a fan hole you are no longer watertight. Use low-power parts and you are probably fine. One nice aspect of keeping the inside a littel warmer is that you limit condensation inside. Use light colored boxes (or better, unpainted silver) to reflect as much sunlight as you can to limit heat in the summer. It's smart to put a 1/4 pound bag of dessicant inside too - eats up moisture that you do not want condensing out on your PC.

    Note: you are going to have issues with getting space on poles. Talk to the power and phone utily first - they may donate space, but there are rules about how the box can get mounted - you have to honor the "climb space" so that repair guys can work, etc.

    Note: use silicon goop around your antenna through-hole - even if you use good rubber gaskets. The gaskets never hold, and the silicon goop is good insurance. Plan on inspecting yearly and replacing the outside goop layer... it deteriorates in the sun and heat.

    Best of luck! Write me if you need more info.

  • A Faraday Cage is simple.

    Have you ever heard that the best place to be
    during an electrical storm is your car (assuming
    its not fiberglass)?

    Basically the idea is that electricity travels
    around the outside surface of a structure. (at
    least static electrictiy does or AC with REALLY
    HIGH frequency). So...

    If you have a large metal box around something..
    and you ground th ebox...then lightning can strike
    the box and ground out...and never have any effect
    on the inside of the box.

    I have seen a person inside a metal cage rub their
    hand along the inside of the ALL METAL bars while
    it was being struck by lightning from a huge
    Van DeGraff generator (the original Van DeGraff

    The Faraday Cage also inhibits all electrical
    signals. It is the reason that computer cases are
    shielded...its a small faraday's cage to keep
    RF inside the box.

    Remember "The Jar" from Enemy of the State?
    Faradays Cage

    An interesting note...on the Van deGraff generator
    at the Museam of Science in Boston, Van De Graff
    himself had his office INSIDE one of the
    discharge globes at one point. Since Static
    electricity gathers on the outside of the globe
    being inside is perfectly safe.
  • But can it stand up to Mr. T?
    The site doesn't say whether or not it's helluva tough.
  • By default, the computer on the mast would be grounded -- power connections. :( I suppose you could figure out a solar array...
  • The Apple AirPort. I've been hacking on this for a few days now with my notebook running SuSE 6.2 and a WaveLAN Gold.

    The AirPort is cheap ($299), encased in plastic already, is in reality just a WaveLAN IEEE card with 56K modem and 10^T ports, acts as a DHCP server and NATting bridge, and is SNMP configurable/monitorable. And it has a small footprint and comes with mounting hardware.

    I'm currently working on figuring out how to reprovision one of these things using only SNMP calls, so I can code up a quick app under Linux to do the job (it currently can only be provisioned using a Mac and their provided software).

    With WaveLAN Gold cards (128-bit encrypted streams, 11MBit) selling for $200 these days, it's an attractive solution.
  • Pardon me for not making them links - I'm hadicapped at work [drum roll] I use Microsoft.)

    So do I ... what's the problem? Here are your darn Slashdot [slashdot.org] and Stanford [stanford.edu] links.

    (Mutter, mutter, young people today don't know their HTML tags, or what?)

    Regards, Ralph.

  • ...am I the only one that has dreamed about irc'ing from underwater? Someone needs to come out with some waterproof laptop...call it the h2oBook or something. Think of all the poor marine researchers stuck underwater for long stretches of time, cataloging fish, watching the coral grow and other such tasks. Its about time someone started to hit this market up....and hey, wouldn't you love to be online from the bottom of your pool with a webcam for all to see?
  • If you could reduce the size and power requirements then it is much easier to build an armored enclosure. While searching for Cool Stuff for my Palm Pilot I ran across this site:


    .. it's a single-board PC running a Motorola Dragonball processor, 2M of Flash and 8M of RAM, Serial and Ethernet controllers, and 18-pins of general purpose IO, some of which can be used to drive an LCD display. All this is packaged on a little 30-pin SIMM module, and consumes 3.3 volts. The Dragonball CPU is what powers the Pilot.

    It could run off rechargables, and have a really small power supply to connect to the grid (or even a small solar array would be more than enough to keep a set of rechargables topped off for a few days of cloudy operation).

    Oh yeah, it runs Linux. Although it is very limited, at 8M RAM, it may be all you need. The only problem you need to solve is getting wireless to work with the board (maybe some of those unused I/O pins?).

    Something that small could be totally encased in polycarbonate - that would eliminate any worry about condensation. Imagine the whole thing, solar panel on top, circuitry on the bottom, encased in a solid block of polycarbonate! Wonder what the MTBF of that puppy would be?

    (guess the rechargables would have to be external, unless they come up with the NiEternity battery)..

  • The ATM machines are probable the best to use for this applications. Just back up truck, attach the chain and let 'er rip. Oh you can try to conact the company that makes the ATM's...
  • In the white paper on the WaveLan site they mention that Carnegie Mellon University in Pittsburgh is actually implementing a WaveLan system across their campus. I'd talk to them before you do anything. Anyone from CMU's IT department care to comment?

    WaveLan white paper [wavelan.com]


  • This may be off-topic, but did you guys see this!?


    Now, if we can just boot Linux on it...so much for the Visor!

    D'oh! My next computer!
  • by Xtacy ( 12950 )
    what about using a mips processor (like the netwinder), from what i hear they use VERY little power consumption, dont need a fan etc etc...

    Just a thought
  • As one of those marine researchers... I gotta tell you, the main problem is not getting the computer waterproofed, but setting up a support system so that you can type. Think about it: gravity is a wonderful thing. Both for keeping the laptop there and for keeping _you_ there while you type. Realistically, we tend to create specialized single-function devices for diver operation. If it can be done with a single switch (magnetic, usually), that's the way we go. But, that's not to say that if someone offered me an underwater laptop, I wouldn't take it!
  • if you need to compute outdoor !
    look this !
    its very interressting !
    more big than usual laptop computer, but, interresting ;))

    Amazonas ;))
  • If you want your equipment safe from environmental conditions get a NEMA enclosure. If you don't mind being a little creative you could mount an entire computer system in a NEMA enclosure or even better work with a company to customer configure one of their enclosures for you.
  • Your entire case at sub-zero temperatures... 1Ghz here we come :)

    Of course this doesn't work if you live in a hot country [jealously vibes]... grrr..
  • What's the problem with cold weather? I thought cold was good.
    I myself thought of submerging my computer in liquid nitrogen
    (which I have plentiful access to) for OC'ing. Please let me know of
    any potential problems.
  • Check out industrial shops. They have 100% sealed cases for use down on the factory floor's and are EXTREMELY sturdy and secure. If i wasn't at school right now i would look them up for you..but back on to AP Computer Science
  • This is something I started almost 3 years ago with Airinter.net [airinter.net] The wireless is quite robust (30 mile range with up to 512k frequency hopping spread spectrum). It was designed for the military and runs off 12volt DC. The equipment isn't very cheap, but works well for a metropolitan WAN.

    the routers are embedded linux systems running all off a boot e-prom and loading OS over wireless, keeping the rest in cache/ram.

    The south-east where I was starting this wasn't quite ready for it, so the company is gone now and I'm in San Francisco. However if anyone is serious about doing something with wireless & linux please feel free to get in touch with me and I'll pass you onto the vendors.

    btw the linux router is something you have to assemble yourself. So get your eprom burners out & figure out how to get a NFS mount via serial connection and boot kernel only! :)

  • Lucent has a product called WaveAccess that is specifically designed for the outdoors. WaveLAN is more internal... Wave Access [waveaccess.com]
  • After reading many of these comments, it got me thinking about wireless technologies. It seems to me that using a Linux box with wireless transceivers indoors is fine, or maybe two neighbors setting up a little wireless network, but when it comes to large-scale outdoor deployment, it seems to me that it'd cost more to develop a Linux solution than it would a custom-tailored embedded solution. Anyway, wouldn't it be cool to be able to purchase DSL service from your local ISP, but instead of running the phone line into a house, run it to a little gizmo on top of the pole? This little gizmo would have a DSL router-wireless lan bridge inside, and would be a tiny little thing not worth stealing. If it was damaged by lightning, it would be cheap enough to replace. Possibly it could be powered off of the same telephone line it uses for the DSL...I don't know...I'm not an engineer, so I'm not sure if that's possible. Anyway, it's not to hard to find a pole with a step-down transformer on it, and I'm beting if you contacted the power company (you're going to have to deal with them anyway in order to get the gizmo on top of the pole) they'd be able to get a pole-mounted meter hooked up to the 120V powerlines...just like the meter on the side of your house. And your little gizmo would have a little transformer to step down to whatever voltage/amprage it needs. As far a power consumption charges, i've seen power meters equipt with little transmitters so that the person who checks your meter can get a reading without actually having to read it off the meter. (So these poor people won't have to climb the pole on a Minnesota Winter day with a windchill of -50F, for e.g.) Or, some might even have the little fax circuit to sends a fax to the billing office each month over the same phone line that that DSL service is provided on (my water meter has this.) Hey, even better: wouldn't it be nice if local ISPs got togeather and setup a metro-area wireless LAN. Then all you'd have to buy is the little wireless LAN PC Card for your laptop, and let the ISP deal with what goes on top the pole. Just some ideas...
  • what about using a chording keyboard? Lets forget notebooks for a moment,
    and lets talk waterproofed wearable PC, with HMD display (brings to mind ideas for displaying it on the lens of the goggles.) and a waterproofed chording keyboard. then you would have the same manuverability, and the coordination problem should be moot, as the chording keyboard is one handed, and has a strap that attaches it firmly to the hand.
  • Environmental enclosures for pole-mounted equipment are just fine and dandy. They are ribbed (fins on them) metal cases that are fully gasketed, 1/4 inch thick aluminum and/or steel, and after installation on a pole, would definately be grounded.
    Yes, you have a problem with the antenna.. but that's what lightning arrestors are for!
  • I know you can get environmental enclosures.
    The only real reason for an Access Point is that it can handle multiple radio domains, so as to releive congestion if you have many remote stations in the same area. (if you simply use the pc cards to do it, it will work fine, but all share the same channel.)

  • by Anonymous Coward
    My company sells exactly what you're looking for. It can be custom configured to whatever specs you want, heaters, air-conditioners, batteries, etc. Using standard rack-mountable equipment.

    (800) 443-4742 ask for Keith Dykes, tell him Darren sent ya!

  • Actually, you can under Linux. It's not pretty, but it works pretty well. I have Webgear Aviator cards: one in an ISA pcmcia desktop bay and one in my Libretto. What you do is on boot put an ethernet card and the wireless pcmcia card both into promisc mode and run the BRCFG utility. The details are in the BRIDGE-howto. I ran into a problem where the remote machine couldnt see the bridge (my fileserver... DOH!) but could see everything past it, so I added another NIC and another IP and it worked fine. I detailed how I did this on my little YALP on our webpage. Oh yeah, if you do this dont eject the desktop card or hell breaks loose :)
  • If these things are going to be outside, take special note of the humidity note: non-condensing. If you get dew on your plants and grass early in the mornings, you'll probably end up with a wet motherboard.

    "Dripping water" resistant doesn't mean crap. You can probably claim most any indoor AT case is "dripping water resistant."

    Also be careful about the temperatures. Granted, if it's up 24/7 you *probably* won't have to worry about it getting too cold, but if the temperatures inside your computer case at home tend to climb to 100+ degF, just think what it'll get to sitting in the hot sun.

    I haven't read anything about these, but it seems like they're more appropriate for indoor/climate-controlled industrial use, not for outdoor use.
  • Ok. Ok. I'll learn the HTML tags....mutter mutter...old farts...think they know everything....
  • I'm surprised there aren't underwater housings for
    palm pilot. It would make a good dive computer,
    and there are all kinds of applications in environmental and wildlife research. Hey divers,
    has any of the camera housing mfgr's made one yet?
  • The problem here is that you have the recieve and transmit on the same cable
    This is typical for consumer-grade equipment.The T/R switch is built into the gear (why would you have it external, when your power amplifier and receiver front-end are right there?) and there is no provision for anything other than an antenna.
    The original poster here didn't specify this, and might have meant that the recieve and transmit channels were taken seperately to the antenna(s).
    Easy way to find out:go read the specs on the Wavelan card. ;-)

  • > Actually, the cage doesn't have to be grounded.

    > Like charges repell. As such, the electrons will
    > move as far away from each other as possible.
    > That means they end up on the outer most surface > of the cage.

    Yes but...if it is truely not grounded (In the
    case of lightning...everything is grounded...
    afterall...it can make its own ground connection
    ;) )

    Then the static would build up on it...and the
    next person to come close enough to it that the
    air between them and it is negligable...would get
    the hit.

    I supose it owuld make a nice security system.
    Touch the box...die.

One can't proceed from the informal to the formal by formal means.