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Wireless Networking Hardware Hacking Toys Hardware

Build Your Own Solar Powered Hotspot 144

hode writes "Popular Science has a how-to article up on turning a backpack into a portable, solar-powered Wi-Fi hotspot. Possible uses include providing Wi-Fi access for a road-trip caravan." From the article: "Its secret ingredient: the Junxion Box. Plug a cellular-network card into the book-size open-source-based device, and voil--instant Wi-Fi hotspot, with speeds averaging around 700 kilobits per second. To power the box, I wired it to a 1.2-amp-hour battery and dropped both into the Voltaic Systems backpack, which has a built-in solar charger."
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Build Your Own Solar Powered Hotspot

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  • Well... (Score:5, Insightful)

    by DanielNS84 ( 847393 ) <DanielNS84@gPLAN ... minus physicist> on Friday July 08, 2005 @07:38PM (#13017790) Homepage
    I can't help but wonder how well this would work if it rained during your whole weekend camping trip? Since that would seem like the time you'd want to use it. ;)
    • Re:Well... (Score:2, Insightful)

      by Anonymous Coward
      Well, if you're going camping anywhere that has celluar coverage, It isint really camping ;)

    • I can't help but wonder how well this would work if it rained during your whole weekend camping trip? Since that would seem like the time you'd want to use it. ;)

      Huh? Solar panels are waterproof and powered by light. They aren't powered by heat or dryness. Repeat after me: photovoltaic.

      • Re:Well... (Score:2, Interesting)

        by hellanacho ( 893266 )
        but if the clouds were blocking the sun...
        • It depends a) how good the cells are and b) how much power you require from them. If you didn't notice, everywhere does not go pitch when the sun is in!

          More important is why the hell anyone would go camping with internet access; even I am not enough of a wuss/geek to spoil it that way.

        • but if the clouds were blocking the sun...

          The light light still gets through the clouds. Have you noticed that on overcast days, you can still see stuff? That's because light is reaching the earth through the clouds. You must have a pretty crappy solar panel if it doesn't work on overcast days. And it only has to power a wireless router! That's no big deal at all.

          Also, there is this wonderful technology that stores energy generated by solar cells. They are called batteries, so, you could even use the syst

  • Wasnt something like this featured at BurningMan? Seems an ideal case for something like this, unless your family roadtrips include browsing /.
    • Does Burning Man have cell coverage? I'd guess not.
    • Re:eh? (Score:3, Informative)

      by macmurph ( 622189 )
      Burning Man already has WiFi internet access. I've used it myself.
    • Making /. portable isn't very difficult at all. Just take that last 3 weeks of stories and randomly read 10 of them every day. Make sure you have 2 anti-Microsoft stories, a Google is going into X market story, and an off topic YRO story every day and you'll never know you're not connected to the Internet.
  • by robyannetta ( 820243 ) * on Friday July 08, 2005 @07:40PM (#13017804) Homepage
    If you connect to it, you too can be arrested [slashdot.org].
  • Small Problems... (Score:5, Insightful)

    by dancpsu ( 822623 ) on Friday July 08, 2005 @07:41PM (#13017807) Journal
    1) This thing costs over $1000

    2) EV-DO [nwsource.com] cellular internet service for the internet connection is $80/mo

    Maybe it would be better just to deal with being away from the internet when you're camping...
    • Maybe it would be better just to deal with being away from the internet when you're camping...

      Sure it would save some power, but how would I deal the headshot when the enemy comes?
    • Plus, I mean really, camping and outside? If you're that big of a nerd, why would you go camping or even step outside? Those rumors of the day star which our planet orbits could very well be true! Better save the $1000, stay inside in your parents' basement, hide from the near-by day star, and surf Slashdot on your constant high speed Internet connection.
    • "Maybe it would be better just to deal with being away from the internet when you're camping..."

      What is this "away from the internet" of which you speak?
  • 4 Watts? (Score:2, Interesting)

    by USSJoin ( 896766 )
    Well, if it takes 4-6 hours (from TFbackpack) to charge a cell phone, is the box going to be charged in real time from this backpack?

    I guess I think that you wouldn't need the backpack to provide Wi-Fi to a caravan, as mentioned in TFA, and if you can't charge while hiking....
    • 4 watts is a bit low, probably. But you get more power out of the solar cells directly than you can cram into the batteries -- when batteries charge, they waste some of the power fed to them through heat loss as the reaction is reversed, and they also waste some when outputting the power.

      And the system is really pricey. What we really need is a dirt-cheap 14-28 watt 48V system -- 14 watts will run anything that can run off PoE. Lots of stuff in the pipeline WRT solar cells that can self-assemble at low
  • by Sv-Manowar ( 772313 ) on Friday July 08, 2005 @07:42PM (#13017817) Homepage Journal
    Obviously the mobile internet service required for this particicular hotspot is expensive, and you'd be mad to want to offer it for open access at your own expense, but what caught my imagination more from the article is the idea of a 'personal network' to allow all of your devices to talk to each other via wifi. As more devices we carry around become wifi equipped imagine if your iPod, phone, psp and camera are all enabled & communicating with each other, having them all on a common network and working to each of their strengths (the psp using the ipod for storage, viewing images from the camera using the psp then uploading them via the phone.. , etc) seems to have real potential and be something that would enhance the usability factor of each device greatly.
  • Whew... (Score:4, Funny)

    by cobrabyte ( 626911 ) * <cobrabyte@@@mac...com> on Friday July 08, 2005 @07:42PM (#13017820)
    Definitely had me hooked until I saw the price tag.

    Can pay someone to run back and forth to my computer for that much money.

  • Finally! (Score:5, Funny)

    by Valiss ( 463641 ) on Friday July 08, 2005 @07:44PM (#13017828) Homepage

    I can play counter-stike when camping! No more annoying so-called "fresh air" needed.
  • by iamdrscience ( 541136 ) on Friday July 08, 2005 @07:50PM (#13017864) Homepage
    I've been making my own solar powered hotspots for years, all you need is a magnifying glass. Place it an appropriate distance from the ground and it becomes ideal for heating up small areas with only the power of the sun!
  • Providers (Score:5, Interesting)

    by fingerfucker ( 740769 ) on Friday July 08, 2005 @07:52PM (#13017877)
    To get full internet connectivity, you have to be on a service plan with one of the 1xEVDO cariers. Currently, those are: ACS, Alltel, Sprint, Verizon, Bell Mobility (Canada), New Zealand Telecom (New Zealand), Telstra (Australia, even though they are still upgrading).

    One of the problems is that 1xEVDO does not contribute to the 3G convergence and really is a fork of a protocol. While 1xRTT is there for CDMA2000, GPRS and EDGE work on GSM-based networks. 1xEVDO seems like a very minor standard in terms of adoption, and its only benefit is lower capital needs for deployment. However, it does not really scale long-term.

    To me personally, it seems 1xRTT and EDGE will eventually prevail.
    • Thump (Score:4, Interesting)

      by Electrawn ( 321224 ) <electrawn@nOSPAm.yahoo.com> on Friday July 08, 2005 @09:56PM (#13018444) Homepage
      I hate it when someone throws a bunch of buzzwords and sounds intelligent.

      EDGE is really just 4x GPRS, or "2.5G"

      The upgrade path to 3G for GSM carriers is to UTMS/WCDMA.

      For CDMA, the 1xRTT upgrade path is to CDMA2000 EV-DO.

      Between the two, EVDO can fall back to 1xRTT IS95 seamlessly. UTMS can't, although it has a speed advantage.

      1xRTT and EDGE are deployed everywhere. It's EVDO and UTMS that one should be looking for.

      Whats amusing:Watching Nextel trying UTMS iDEN hybrid. Ping Reply: Please wait while the Nextel IP Address is found.

      Scaleability (as far as speed) is only a minor factor in choosing an upgrade path. Carriers care about Capacity, netowrk reliability and footprint. For that, 1xRTT(IS95) and EVDO lay the smack on GPRS/EDGE/UTMS. ...and I am happy to have left the Cell industry as of yesterday.
  • by hilaryduff ( 894727 ) on Friday July 08, 2005 @07:56PM (#13017902)
    id get robbed of that stuff in under 30 minutes
  • The main ingredient here seems to be the Junxion box. But can't you replicate that with a bridge device on any laptop? The EV-DO card brings in the signal. Any el-cheapo wireless access point broadcasts it, and the bridge (in software) bridges the two devices.
    • my guess is that junxion box is really a soekris or wrap board with a custom case and a customized installation of bsd or linux. those systems are ~$200
      • my guess is that junxion box is really a soekris or wrap board with a custom case and a customized installation of bsd or linux. those systems are ~$200

        It is. We looked at one when looking to build the same thing (1xRTT to ethernet router in our case) and just ended up buying a Soekris box and a Verizon wireless PC card and built a mini-linux distribution based on Debian to put on the system (about 38 meg cramfs image on a compactflash card). Works just fine. I think we spent about $350 on the whole

  • by tripslash ( 683760 ) on Friday July 08, 2005 @07:57PM (#13017907) Journal
    Now YOU too can impress Bigfoot and all his friends with your very own HotspotPack(noTM)! All for the low-low-low price of ... $1065.50! Some assembly required, backpack not included, not responsible for lost or stolen identities due to running HotspotPack(noTM) in unsucured mode, do not use HotspotPack(noTM) in conjunction with hooded sweatshirts/sunglasses, or burkas.
  • If you have alot of neihbors around with thier own WiFi routers, and alot of the channels are used up, how do you make sure you are not connecting to someone elses (which can be illegal.) Right now I live in an area with only country folk on Dial-Up where few people have wireless (other than the local school) so I don't have to worry about this yet, I evne get Adelphia's advertised permium broadband speed. But when my neihbors switch over, I am worried about connecting to their router, and I wouldn't really
    • If you have alot of neihbors around with thier own WiFi routers, and alot of the channels are used up, how do you make sure you are not connecting to someone elses

      Use encryption and change the SSID on your wireless router and use the same settings on your wireless card(s) and you should only connect to your own router.

  • Price not a problem (Score:1, Interesting)

    by 808paulson ( 852724 )
    Price does not matter if your company is paying for it.

    I saw something very similar to this in Las Vegas. They were using a back pack with linux, gps, and 2 evdo to transmit a live feed from an HDTV camcorder. And oh they also had a very fancy looking audio set up. I think the camera guy had to wear a battery belt and there was a fan blowing into the back pack.

    They have at least $5000 dollars on 1 camera crew and they at least have two crews.

    I went to their website. I didn't know what the website was
  • A how to? (Score:4, Funny)

    by interstellar_donkey ( 200782 ) <pathighgate@@@hotmail...com> on Friday July 08, 2005 @08:02PM (#13017937) Homepage Journal
    That's not really a "How To". It's an idea (albeit a pretty nifty one).

    What's next? Popular Science puts together a "How To" on building your own car? "You first get a metal frame, and then attach two axels to it. Then you get an internal combustion engine and mount it on the front. The secret is putting a fuel storage container near the back, connected through a hose to the engine. That will give it a range of hundreds of miles. We also picked up a set of four Goodyear tires and put them on wheels connected to the axel. PROJECT COMPLETED"
  • by iamdrscience ( 541136 ) on Friday July 08, 2005 @08:03PM (#13017947) Homepage
    This thing, as made in the article, costs over $1000, I would have thought a project slashdot would link to would have somebody rigging up their own solar panels instead of paying $230 for a bag with solar panels on it [voltaicsystems.com] and setting up their own system (mini itx or some such) instead of paying $700 for a Junxion Box [junxionbox.com].
    • Save money -- ditch the backpack. The solar cells don't generate enough power to make the unit run significantly longer. Put the money towards larger gell cells - I just bought a 7 amp-hour 12 V cell at the Dayton Hamvention for $15. A realistic size battery and a good charger will cost considerably less than the Voltaic backpack and give you longer run times besides.
      • Yeah, I was thinking that too, that the PVCs aren't really necessary and batteries would be better, but I think solar power has kind of a neat appeal with people. People like the idea of pulling energy out of thin air and such. Still though, if I were designing such a system I would incorporate a regular battery cell as well, that way you could use solar power and get your kicks from that, but if/when that power runs out you'd still be able to keep using it. It'd be a minimal cost for the battery when you t
    • Last I saw, what Junxion was shipping was 95% COTS.

      The board inside it is a Soekris Engineering 486 class [link] [soekris.com], they boot off of a small CF, and the Linux distro the box runs is a very close derivative of LEAF [link] [sourceforge.net]. (Think it's actually a derivative of WISP-Dist[link] [sourceforge.net], which was sprung from and then rolled back into the LEAF project.)

      They wrote the pretty front end and provide pretty good support for them.

      If you're willing to support it yourself, go buy a $200 Soekris machine and rig one up.
  • Too Bad... (Score:3, Insightful)

    by rivid ( 829046 ) <{moc.liamg} {ta} {zdivir}> on Friday July 08, 2005 @08:04PM (#13017949)
    Too bad that if you opened the backpack in public, someone would probably shout "bomb!".
    • Too bad that if you opened the backpack in public, someone would probably shout "bomb!".
      Huh. Now I kinda want to build one.

      Btw, this has been on hackaday [hackaday.com] for almost a week now.
  • by Wesley Felter ( 138342 ) <wesley@felter.org> on Friday July 08, 2005 @08:04PM (#13017952) Homepage
    You can build your own EV-DO/Wi-Fi router [fbrtech.com] for much less than the cost of a Junxion box.
    • That article rocks, but it would be cheaper still to use your laptop as the router and skip the extra box. The software that makes the box run should do just fine on the average Linux laptop.

      The solar cells are nifty but there are cheaper and more rugged ways to generate power. If you are mountian biking, use a cheap headlight generator set. Your body can put out a good 250 watts, almost 10 times the power needs of a good low power laptop.

  • The lone hitch: Wi-Fi is useless without a hotspot.

    Um, have they never heard of ad hoc networks? Plug in the EV-DO card into your PowerBook, open System Preferences, select the Sharing control panel, click the internet tab, and select "Share you Connection from to computers using ". Same idea, different steps on Windows.
  • I suppose it would be OK for passengers, but you know some jackass is going to start IMing, fragging, looking up pr0n and who knows what else, while driving. Which would be a worse driver? Soccer mom on a cell phone, or computer geek surfing the web.. thats a tough call!!
  • The rain volume is a bit of a myth, but the constant grey isn't.
  • by haakondahl ( 893488 ) on Friday July 08, 2005 @08:17PM (#13018021)
    ...to surf the web where I, uh, do my business. Now I can surf where a bear does his business!
  • Totally Wireless (Score:3, Insightful)

    by Doc Ruby ( 173196 ) on Friday July 08, 2005 @08:17PM (#13018022) Homepage Journal
    How about wrapping the whole package in solar cells, mounting it in the middle of a 1m diameter fishing net, and throwing it up into the trees? Do that with enough to put 3 APs in every 300' radius, all through the woods. Set a server connected to the network (maybe via a remote Pringles can) to ping each one, notifying when one has dropped off the network. Then go find it on the ground, and fling it up again.

    Now you've got a rural area with a truly wireless network. It's easy to maintain the mesh. And these apps are cheap enough that a community can afford to do it, without a big cost per person.
    • Re:Totally Wireless (Score:3, Informative)

      by gotih ( 167327 )
      trees and leaves are full of water and therefore eat wireless signals. not that it wouldn't work, just not as well during the summer when trees have leaves. also, the solar cells would be shaded by the trees.

      now, substitute the tree with a tethered hydrogen filled mylar balloon.... you'd just have to check for vine growth on the tether every so often.
      • Are there solar/mylar H2 balloons for sale? Where?
        • Are there solar/mylar H2 balloons for sale? Where?

          A kite shop in Twilight Beach - just the thing to power your sand-ship at 80 clicks past the bell-trees on the road.

          OK, so it's SF from Terry Dowling, but solar fabrics exist and the possibility is there to stick solar materials on a variety of conducting surfaces by chemical vapour deposition, and on a variety of other things that can handle a bit of heat by the sol-gel process (apply gel to substrate then bake in a moderate oven!).

          A thin coating (micr

          • The tether that holds it to the device and pipes back the power could also be hollow, supplying more H2 to the balloon from a pressurized reservoir in the device. But then, the H2 probably has more power for a fuelcell than the solar cell can supply...
  • only 3 hours? (Score:2, Interesting)

    by gr0k ( 113968 )
    This is cool and all, but maybe I'm reading it wrong. The article is pretty short on details. It says it only lasts 3 hours? Is that 3 hours just off the battery or including the solar panels? If it's only 3 hours even when the solar panels are connected, then it's pretty useless... that doesn't make sense.

    The junxion box though is very sweet. I set one up in my Boss's car recently. It's very slick and easy to setup, even though it's a little expensive. The other problem we had was the slot where th
  • Cheaper solution (Score:5, Informative)

    by iamdrscience ( 541136 ) on Friday July 08, 2005 @08:21PM (#13018046) Homepage
    This solar powered hotspot is $1,000. Maybe an alright price for a consumer product, but a little much for something you'd build yourself, here's a cheaper solution:

    $189 - Gum Stix [gumstix.com] Connex 400xm-bt, a small xscale system running embedded linux
    $25 - CFstix, an expansion board for the above system allowing connection of Compact flash cards
    $70 - Netgear MA701 802.11b Wireless Compact Flash Adapter
    Subtotal: $284

    That ought to be a good replacement for the junxion system in this case, for 40% of the cost.

    As for the solar power, you might want to use the same Voltaic Systems [voltaicsystems.com] bag they used in the article, but you could deck out a bag you already have with solar panels and such and it might be a little cheaper. Hell, if you wanted you could put their solar panels and batteries in your bag, they sell them seperately!
    • Now that I think about it, an even better solution is to just plug the cellular card into your laptop and then plug a wireless card into it as well. What's that you say? The Voltaic Systems bag won't power your laptop for long? Well considering you've eliminated the $700 Junxion system, why not buy two more? Or deck out the one you bought with more solar panels?
      • Well, there is the issue of portability. Three laptops (or did you mean three backpacks) are a lot heavier (or more awkward) than one, and there's likely no room for more solar panels on a single backpack.

        And if your laptop and your wifi card are anything like mine, they won't both fit in your laptop at the same time. So that means using USB probably, and means one more thing hanging off your laptop.

        I'm not sure how practical this idea is in the first place. I guess for someone who lives in the city an

    • You're missing the EV-DO part. EV-DO cards are CardBus, and I doubt the Gumstix supports CardBus.
      • This is true, I wasn't thinking right. Still though, there are similarly priced SBCs with bluetooth and PC card slots. You might have to pay a little more, but still well under half the cost of a Junxion box.
  • Reading the title made me think of burning ants with a magnifying glass as a kid.
  • This article seems like an ad. The project is essentially just plugging a Junxion Box into a Voltaic Systems backpack. If you were looking to make something like this, why would you choose to use something like the Junxion Box? Surely a mini-itx system would do just as well in this situation at a fraction of the cost (half as much?). Who on here was even familiar with this product before this article was posted?
  • The only drawback to the design that it looks too much like a bomb in a backpack. I don't think you want to walk through a train station with one of these.
  • This is very clunky and expensive looking. The PV cells don't look as though they're going to provide enough power except when it's very bright out and you have them pointed directly at the sun. EV-DO also doesn't work well, in a lot of places. It's still in testing. The $1000 for the equipment seems like it could be spent better on mesh wireless gear, or ham radio equipment. But hey! It's what popular science/tech magazines do! They may you say "cool!".
    • The PV cells don't look as though they're going to provide enough power except when it's very bright out and you have them pointed directly at the sun.

      The idea behind PV cells on a backpack is to store the energy in a battery, not to use it all the time. It would be nice if you could get that kind of power out of something the size of your back, but there's hardly enough sunlight hitting your back for that.

      This is very clunky and expensive looking.

      Expensive? Yes. Clunky? No. The whole setup looks

    • Yes, you are right... The photovoltaics in this backpack are claimed to provide 4 watts (presumedly in full daylight and properly oriented). The AP ships with a 12V 1.25A power supply. Given that bricks rarely provide more power than required, I'd estimate the power draw at over 12 watts. This means that it takes an hour to charge the batter sufficiently for user's to just get to the point they've cleared the spam out of their email boxes before the AP's power gives out.
  • So... (Score:3, Interesting)

    by TheQase ( 898432 ) on Friday July 08, 2005 @08:52PM (#13018162)
    What happens when Verizon says "No More" and cuts you off? According to Verizon's TOS: Unlimited NationalAccess/BroadbandAccess: NationalAccess and BroadbandAccess data sessions may be used with wireless devices for the following purposes: (i) Internet browsing; (ii) email; and (iii) intranet access (including access to corporate intranets, email and individual productivity applications such as customer relationship management, sales force and field service automation). Unlimited NationalAccess/BroadbandAccess is for individual use only and not for resale. Unlimited NationalAccess/BroadbandAccess cannot be used: (1) for uploading, downloading or streaming of movies, music or games; (2) with server devices or with host computer applications, including, without limitation, Web camera posts or broadcasts, automatic data feeds, telemetry applications, automated functions or any other machine-to-machine application; or (3) as a substitute or backup for private lines or dedicated data connections. NationalAccess and BroadbandAccess data sessions automatically terminate after two hours of inactivity unless used with a Mobile IP-capable device. We reserve the right to limit throughput or amount of data transferred, deny or terminate service, without notice, to anyone who uses NationalAccess or BroadbandAccess in any manner prohibited above or whose usage adversely impacts our network or service levels. We also reserve the right to terminate service upon expiration of Customer Agreement term. BroadbandAccess kilobyte usage may not appear on your bill http://www.verizonwireless.com/b2c/store/controlle r?item=planFirst&action=viewPlanDetail&sortOption= priceSort&catId=409&rp [verizonwireless.com]
  • If you have an air card and are by some miracle in range of a cell tower, why would you plug it into a $1000 box requiring another $100 battery instead of just directy into your laptop?
  • ...IP over power lines
  • by Anonymous Coward
    You get a Linksys WRT54G (or other hackable) router and put openwrt on it, put it in "client" mode (so it acts like a client) add an external antenna if needed so you can pick up some open wifi hotspot out there (left open for others to use of course) or starbucks etc... You can get up to 2 miles easy outdoors.

    Then on the other end, you plug in a normal router, just pretend that the WRT54GS is a cable modem (it supplies the internet, DHCP and all that on it's ethernet ports).

    Everyone logs into the normal
  • by Cee ( 22717 )
    I don't really get it.. I RTFA, but I still don't understand where you are supposed to get your internet uplink from?
  • I personally think that the image on the page of the backpack looks like something the bomb squad would attempt to detonate after forgetting it in the airport. hehe, "ITS ONLY A PORTABLE WIRELESS HOTSPOT" bombsquad waits... "OH MY GOD, GET HIM, HE'S ILLEGALLY SHARING INTERNET ACCESS!"
  • or even a camping trip...

    90% of our Aussie roads have no cell signal at all. If you're in a town, there might be a signal, maybe, but there will be an internet cafe too. As soon as you're a few km out of town - no signal and if you're in the outback and you've got a cell signal - you're not really in the outback.

    As for the solar powered thing, I think it might be much cheaper (though perhaps not as ecofriendly) to get a converter for the car cigarette lighter and plug into that.

    And I already have a sol
  • Isn't it possible to use one of the computers (laptops) as the wireless router? Especially if the WLAN card can be put into Master mode, or if not, use Adhoc mode instead.

    I've thought that even today's existing WLAN gear can be used in a decentralized way, and I mainly see Managed mode networks as a means of corporate profit (selling an access point even when you could just connect computers directly via WLAN) and centralized control.

    These are possibly stupid questions, as I don't have much experience

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