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Running Linux On Your Swimming Pool 174

Forkenhoppen writes: "Ever considered having a computer look after your swimming pool maintenance? Check out this project by Richard J. Kinch. Mr. Kinch uses a Linux box configured with several shell scripts to control the chlorination levels of his pool."
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Running Linux On Your Swimming Pool

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  • by gatesh8r ( 182908 )
    What next? A device that runs Linux so that their toilet flushes? :-)
  • by Wakko Warner ( 324 ) on Saturday February 09, 2002 @03:55AM (#2978478) Homepage Journal
    Hooking crap up to a serial port isn't exactly the same as inserting a Debian CD in your skimmer basket and installing LILO on your pool's boot sector.

    Anyway, mine runs NetBSD just fine.

    - A.P.
  • by Anonymous Coward
    Hmm, is it just me, or does anyone else have that faint voice in the back of their heads screaming something about bathtubs, blowdryers, and toasters that may have adaptable relevance to this situation...?

    Er, i'm sure it wasn't important, otherwise i wouldn't have remembered that much of it. :)
    • does anyone else have that faint voice in the back of their heads screaming something about bathtubs, blowdryers, and toasters that may have adaptable relevance to this situation...?

      You mean you can hear them, too?? Do yours keep telling you about register 3 being open for 5 items or less?

      Except my faint voice that screams isn't so faint.
  • Hmmm... this really got me thinking, maybe a poll question?

    What do you use Linux/*BSD for?

    I have a firewall/file/mp3/mail server running Debian Linux (Woody), and a desktop system running Win2K and Debian Linux (dualboot).
  • Not bad but . . . (Score:3, Interesting)

    by ahfoo ( 223186 ) on Saturday February 09, 2002 @04:00AM (#2978490) Journal
    How about installing an electronic ozone system? They're supposed to be quite efficient and don't require much maintenance as they're basically just a fancy neon tube that the water passes by. I understand they've been required in many european countries since the seventies.
    • by Anonymous Coward
      An oxygen rich environment exposed to 250 - 254 nanometer ultraviolet light will produce ozone. In a swimming pool, the bulk of the ozone reverts to oxygen in a few minutes. But in those few minutes of ozone uberoxidative frenzy, it will eat any organic matter --yes including candy bars and chopped up corpses although it could take a few months to get rid of an adult corpse using a neon tube and a swimming pool. The teeth and bones should be ground up separately if you're not authorized to dispose of the corpse in question as they are only borderline organic material and will probably just swirl around the bottom of the pool for years.
      But anyway to get back on topic, just using a straight chlorine system is primitive at this point though oddly common in the States.
  • Overkill????? (Score:3, Insightful)

    by jsimon12 ( 207119 ) <> on Saturday February 09, 2002 @04:00AM (#2978491) Homepage
    As much as I am a fan of putting Linux where ever it is possible but lets be honest, this is overkill for the application. There is considerably more mundane technology and none-tech devices that can perform this job, just as effeciently.
    • I've seen worse.

      The local rep for one of the major DSP manufacturers uses the eval boards he's given for home automation... his hot tub is currently controlled by a 600 MIP 32-bit DSP unit.

      He claims the temperature hasn't changed more than half a degree in the past year.

    • Come on! The last thing Slashdot readers want is an article with Linux running on a computer.
    • I loved it when I got to this part:

      I cut up ready-made cables and stripped the ends to attach to the protoboard via cable ties; there's no point in making more work than necessary.

      You don't say...


    • Re:Overkill????? (Score:3, Insightful)

      by ndogg ( 158021 )
      I would not say it is overkill. I have taken care of a pool before (for over half of my life, I have lived in a house with a pool.) Taking care of a pool is a tedious and repetitive task. There are a lot of things that could and should be automated.

      For example, this guy could extend this to controling those self-propelled pool vacuums to clean the pool (and do the backwash as well.) There are actually pool vacuums that propel themselves and clean the floor bottom by themselves. They climb right up the wall and back down. It is a really neat sight to see. I could imagine using the computer, putting the vacuum in a small compartment with an automatic door that the computer could open and close to let the vacuum out. Also, instead of having the vacuum having to run the vacuum nearly all the time like you would normally do (the vacuum has no AI or anything, it largely just goes back and forth), the computer would know the dimensions of the pool and how it is shaped and so strategize the fastest way to vacuum the bottom.

      Also, chlorine is not the only chemical that needs to be put in the pool (but is the main component.) All pools have to worry about algae and the vacuum and chlorine are not enough to handle algae, so a lot of pool owners have a stock of algaecide for that.

      I could also imagine there being cameras on the pool connected to the computer so that the computer could determine if there are people in it, the cleanliness of the pool, etc.

      There are so many tedious tasks to taking care of a pool that having a system that is automated would be a blessing to many pool owners.
    • As much as I am a fan of putting Linux where ever it is possible but lets be honest, this is overkill for the application. There is considerably more mundane technology and none-tech devices that can perform this job, just as effeciently.

      I approve of using a computer for basically any task. It allows you to create managed services; You can see what's been happening. It's analogous to an employee; You can ask them what's been going on. It's a lot harder to log in a simple mechanical system, though it's been done (using time clock technology, or similar.)

      With that said, linux is almost certainly overkill for this project. You could handle every aspect of pool maintenance with a 4.77MHz IBM PC-1 with 64kB of RAM and a pair of 360K floppy drives (one for OS, one for app and logs) running a teensy little program. You would have to develop some custom hardware for the purpose, but you have to do that anyway. I'd opt for PIC chips, as they speak serial without you having to actually do all the work of it.

      However, I would not use the PC. I would use something more or less modern, at least a 486, and run something like linux or some flavor of BSD on it. Why? Because it makes development so much easier, and because it allows you to do other things, too. You could later decide to hook up a PC weather station to it, for example. If it had a precipitation gauge your machine might preemptively add chlorine to make up for the dilution, for example.

      Also, let's not forget the geek factor. Who among the slashdot readership doesn't have some kind of computer lying around unused? Hell, I've got a ppro180 and a 486 both sitting around; I've thrown away 486s, 386s, et cetera, because no one I knew wanted them and I was not about to go on a lengthy quest for a buyer. Might as well use it.

  • Yeah, but (Score:2, Redundant)

    by mESSDan ( 302670 )
    What happens when some script kiddie gets access to your pool's box and raises the acid content so much that everytime you go for a swim, you come out missing 3 layers of skin.

    Or some chemist hacker figures out a way to add "pee" to your pool by modifying what chemicals the program puts out.

    Just food for thought. ;)

    • Thought this would be appropriate

      Homer: Ah, there's nothing like rising with the sun for a quiet,
      peaceful dip in your very own pool.
      [cheers, dives in]
      [comes up covered in algae, yells and sputters]
      [Lisa walks out] Lisa, the Blob has got me! Don't touch me or
      he'll get you too.
      Lisa: Dad, you have to put chlorine in the water every day to keep it
      Homer: Chlorine, eh?
      [later, all the kids scream and rub their bloodshot eyes]
      Ralph: [coming up] Ow, my face is on fire!
  • dude! (Score:2, Funny)

    by saviorsloth ( 467974 )
    My family in The Sims could so use that. a free cookie to the first person to make that an item :)
  • by Anonymous Coward
    This is the app that will finally bring Linux into the mainstream. I had previously thought that the linux powered christmas tree would win over the masses, but it turned out to just be a computer running linux, that sat in a christmas tree.

    This looks like the real deal however. Watch out Microsoft.
  • ... and Tripwire to turn it purple if someone pees in it.
  • But its still VERY cool.

    I'd think there would be more decent home automation tools/devices around.

    Unfortunately there isn't that much out there, and what there is mostly identical to what my 55 year old EE neighbor had from the 80's when he played with home automation on his vic 20.

    Happily this article has some links and such that provide practical examples....

    Still the best example home automation is the Coffee howto ;)
  • while the use of calculated sunrise and sunset times are pretty neat, a simple photosensor might be an idea too. (Of course, the photosensor might get dirty and give faulty data.)

    And what happens if the server hangs (which is possible if not likely)? The pool might get much more clorination than he hoped for.

    Parallel backup safety systems is probably a good idea here - perhaps just a 555 variant (cascaded?) circuit with a long, if not accurate, delay time that shuts down the system if it ever stays on too long.
  • by WIAKywbfatw ( 307557 ) on Saturday February 09, 2002 @04:08AM (#2978517) Journal
    I'm willing to bet it's Aqua.
  • Untill something goes terroibly wrong....

    "Mr. Kinch uses a Linux box configured with several shell scripts to control the chlorination levels of his pool.""

    Imagine what would happen if there was a big bug ;) Like say, and infinite loop exit error while adding the stuff...

    - Knut S.
    • by nomadic ( 141991 ) <nomadicworld AT gmail DOT com> on Saturday February 09, 2002 @05:19AM (#2978632) Homepage
      "Thanks for inviting me to the pool party!"

      "No problem, Ed."

      Ed enters the water.

      "Ahhh! It burns!"

      "That's impossible, Ed. You see, the chlorination levels are controlled by several scripts running under Linux. It's Open Source, so it's stable and it can't help but work."

      "For the love of all that's holy, someone help me!"

      "You see, with open source any bugs that would have cropped up would have been immediately been fixed by the many independent programmers around the world who check the source code."

      "Oh the pain! My skin is being flayed from my body!"

      "See the neighbor's kid over there? The one in the Limp Bizkit t-shirt with the baseball cap? He's one of the many open source coders around the world who maintain the system I use to automate my pool. Don't let his age, lack of education, or immaturity fool you; because he's an open source coder he's far superior to any corporate drone with a masters in CS. Now don't you feel better?"

      "Oh, the pain! It's like acid!"

      "Ed, the chlorine level is precisely monitored, as I've been telling you. Whatever you're feeling is most definitely not the result of chlorine."

      Ed finally manages to crawl out of the pool. His skin is an angry red, and his hair has turned white.


      "Ok, I see how it is, Ed. You're one of those Microsoft supporters, just trying to spread FUD about the open source movement. I think you should leave."
  • Pretty cool. (Score:3, Interesting)

    by Soko ( 17987 ) on Saturday February 09, 2002 @04:16AM (#2978537) Homepage
    Something like this would be a prime candidate for Embedded Linux running on a smaller, weathertight, dedicated device instead of a full blown PC tho.

    The headline remined me of what I used to say to the people (several years ago) in the office when I had to re-boot a NetWare server:

    "Everybody out of the memory pool!!"

    • Embedded Linux is certainly a prime candidate, with a network connection for updating the configuration. The only catch is that most embedded linux boards that I have come across cost around the same as an old x586 or more. The day I can get an embedded Linux board for less than $300 (USD) is the day that I will consider making a purchase.
  • Similar Project (Score:3, Interesting)

    by T3kno ( 51315 ) on Saturday February 09, 2002 @04:18AM (#2978540) Homepage
    I am thinking about doing something similar with a reef tank that I am going to build. Hook a cheap 486 or pentium up to all of the monitors and dosers that I need to run the tank. I would also like to hook it up to the light ballasts and pumps and have them controlled by some sort of software that mimics the sun and moonlight in the corals natural habitat. What would be really cool is some sort of random cloud generation, as well as random storms in the winter. Even some water temperature variations would be nice.

    I was origionally going to use X10 for the design, but I am going to look closer at his custom designs and possibly use those. I really would like to stay away from X10 because of those damn popup windows that they started. I really dont want to support that sort of company.

    I am really glad he did this project, it really gives me some good ground work on which to base my smaller project on.
    • Are 11 months not enough?
      • "Are 11 months not enough?" you ask. Hrmm.

        Well, the thing is, your flippant little quote illustrates exactly the quote you're responding to. We've got Miss Native American, Miss Black America, Miss $non-white$-America - but if we (us damn whites) were to have a "Miss White America" or "White American History Month", we'd be branded racist, and culturally insensitive.

        The NAACP and its sympathizers have done more to damage 'racial relations' than any other movement. It's the exact attitude that any group is 'special' or different or should be recognized as such that's preventing true harmony among people of differing skin tones and language.

    • Re:Similar Project (Score:1, Informative)

      by Anonymous Coward
      I must say it again. X10 and are two different things. Type X10 into google and you'll see other companies selling modules. X10 is a protocol. is an annoying popunder ad marketing piece of junk. Don't confuse the two.
      • Worse yet, the ads are misleading. They imply that the quality of images produced by an X10 camera is adequate.

        Fry's had a demonstration of the XCam, and the picture was so fuzzy as to be virtually unusable. Even the voyueristic possibilities inherent in the X10 ads would be destroyed by the awful quality.

        You have been warned.

      • --

      • When is white history month, or chinese history month, et al?
      July. As in "July! July about dis, 'n July about dat. All you white people lie, lie, lie!"


  • Feb 10, 2002- A test script was run to more accurately monitor the chlorine levels. everything seemed alright until a power surge interrupted the script. the box hummed strangely. The water took on an eerie glow. arcs of electricity shot through the water. steam floated over the water. small globs of matter formed and floated to the surface. they began to take shape. the realization struck me like a bat...the machine had created primordial was god. dun, duun, DUUUN!
  • Just thinking about a power outtage, or any other thing to cause the box to die, bacteria spawing pool anyone?

    i know he would still check it once in a while manually but still
  • A Linux box to control the porch light! It receives sunrise/sunset times over the internet to decide when to switch the light on and off. It even factors in weather related adjustments!

    We can finally throw away those damn photocell controllers!

  • Water + Electricity (Score:2, Interesting)

    by rackrent ( 160690 )
    = smart people who can negotiate them. By the time any kind of control for the pool filtering & lighting system reaches it, it's gone through so many physical and electrical insulations, that it should be completely safe. Heck, I could control the Atlantic ocean if my blender ran more than Redhat 4.0 and I had the right kind of seals.

    Seriously.... from what I saw on this page (before it got /.'ed), this is a pretty neat idea, as it would elminate all of those stupid manual timers (which generally keep very poor time) and eliminate the need for continuous monitoring of pool chemical levels.
  • by OmegaDan ( 101255 ) on Saturday February 09, 2002 @04:35AM (#2978577) Homepage
    this is cool, but ... I always loved those pool cleaner bots that drive around the pool bottom and pick up debris. Could we get a rediculously complicated computer controlled one? let it be run by perl scripts and have a mysql database to log the ammount leaves picked up and ammount of urine in the pool. This will be served from the pool robot itself running a custom apache rig via an 802.11 underwater access point :)

    this would be a proper geek project
    • I always loved those pool cleaner bots that drive around the pool bottom and pick up debris. Could we get a rediculously complicated computer controlled one?

      This is a pretty good idea. I've got a pool navagator, and it works pretty good, but I have an "L" shaped pool and the thing shys away from going into the shallow end around the corner. It's a pain in the butt to have to keep relocating it to the shallow end.

      Point: there is money here. This pool vacuum runs about $400, and from what I've seen, pool owners don't care about spending $400 for something to eliminate the tidium of cleaning the pool. So there is money in this market.

      And why stop there? The same technique could be used for lawnmowers, much like this one [] but you wouldn't have to bury tracks.

      Sounds like an opportunity for some coders to turn a buck..
    • From what I learned in school, emitting radio-waves under water has no other effect than warming it all up a bit.
      That's why submarines use sonar and no radar, as water doesn't allow them microwaves to properly "move around".

      Or am I wrong?
      • From what I learned in school, emitting radio-waves under water has no other effect than warming it all up a bit.

        That's why submarines use sonar and no radar, as water doesn't allow them microwaves to properly "move around".

        Or am I wrong?

        Uhm, I forgot about the real issue:
        That's why you won't be able to use some 802.11-Access for this, as it's based on electro-magnetic waves, known as microwaves AFAIR.
    • Those robots are completley powered by water pressure. Maybe this calls for a water powered Linux system?
  • Well, that's wonderful. But why is this news? Does he really need Linux to do this? I bet a Sinclair ZX 80 could do the job as well. Don't get me wrong, I like Linux and all, but this story hardly seems a prime example of why Linux is better than anything else. Just my $0.02.
    • Absolutely correct. I could do a similar thing with my 18 years old cpc464 (4Mhz Z80, 64Kb ram)under Locomotive Basic (default rom basic.)

      ZX80 probably will need a 16k expansion card, and hand translated machine code, but sure, it can be done.

  • by LadyLucky ( 546115 ) on Saturday February 09, 2002 @04:49AM (#2978598) Homepage
    try {
    PoolState poolState = pool.getPoolState();
    if( poolState.getChlorineLevel() < MIN_CHLORINE_LEVEL ) {
    } catch( KidPissedInPoolException kpipe ) {
    MainsPower.reRouteTo( pool, MainsPower.MAX_VOLTAGE );

    Sorry. I just had to.

  • Just one doubt - Is this guy talking about the paged pool or the non-paged pool?
  • Boy, I can't wait to do this to my spa.

    I'll guess I can get an adequate Linux box for $300. Then I need power to run it, special hardware to handle the chemicals, and of course about $500 worth of my time (at best) to set it all up.

    When I'm done, I can get rid of that $5 timed-release dispenser that has kept my chlorine levels stable for years. The chemical costs will remain about the same, of course, but hey, I can get a geekiness award.

    As to the timer, if I were going to waste my time to create elaborate software that knows the daylight schedule, why not just wire up a few SCR switches to a photocell? Or better, run the pump at night when evaporation is lower and never have to change the timer settings?

    I figure he'll earn his money back in about 2 decades. By which time the PC will have long since rotted.

    OK, this kind of project can be fun for its own sake. But let's not pretend it makes economic sense.

  • apperently this guy has more.
  • by flacco ( 324089 ) on Saturday February 09, 2002 @05:25AM (#2978644)
    When I try to load the page, all I get is a blank screen with this across the top:

    Swimming poo


  • /.-ing some fool, now he's gonna have a $1000 internet bill. At least, have someone mirror their pages on some service that is /.-resistant. Should we feel guilty? Probably.

    Linux flushes a toliet, it cleans your Windows, and it scrubs so you don't have to!
  • Surely Tux will make the pool freezing cold so he can go in for a dip now and again - so be ready for that when you jump in!
  • Um.... (Score:1, Informative)

    by SkewlD00d ( 314017 )
    1) This guy should learn chemistry first, if he's going to try to write ionic equations.

    Hypochlorous acid is HClO.

    2) Breaboards are not ideal for switching loads or controlling things as a permanent solution, probably should make a PCB and solder the components on, as breadboards tend to make crappy connections (similar to a cold solder joint).

    3) Probably should use optocouplers and protection diodes on *anything* you build and attach to your computer(s).

    4) Real men use languages like perl and c, not wussy shell scripts. jk, at least it's not labview or vb script on winbloze or macs.

    My two centidollars.
  • I know from experience how irksome it can be to have to regularly monitor and maintain pool chemistry, so I thought this could be interesting.

    I don't meant to belittle this effort, but it's important to notice that this system specifically doesn't (yet) monitor chlorine or other chemical levels. That's a shame, since it seems to me like this could be the most powerful aspect: a continuous feedback system that could, say, adjust the chlorine level when it gets too high or low.

    It's hard to fault him for that, since it seems like it would be impractical to do actual monitoring, as the article says: The technology required to sense these chemical parameters requires a delicate probe be inserted into the plumbing, with an amplifier and analog-to-digital converter interface to the computer. These probes are rather expensive at about $100/each, require calibration every month or so, and wear out in about a year. Without some less-expensive, improvised alternative, these costs seem to exceed the possible savings in reduced chemical demand or manual dosing.

    But the net result here seems to be not much more than an elaborate scheduling and electrical system -- a glorified timer-box that happens to be running Linux, if you will. It does have a few advantages: more complex configuration possiblities, and the capability to determine daylight hours. But I still have to question whether it would ultimately be less costly -- in terms of time as well as money -- to implement this using more mundane hardware.

    (I do note that this page has a lot of detail about the chlorination system, which looks to be well written. The liquid chlorine pump setup sounds like an impressive achievement -- but the Linux part is not quite as special as it's made to appear here.)

  • Using a linux box to do a job that can be done by some basic electronic circuits deserves praise and applause?
  • Well, it's apparantly being slashdotted a bit, and when I went there, I saw only the following at first:

    Swimming Poo

    I just had to share that with you people :-)
  • What can't you do with them ?? It's like statistics..... What can't you prove with them ??
  • How bout a project for Linux for your Mother's Desktop?
  • by eske ( 211780 )
    I don't hope he is running the pool program on the same as his webserver....maybe a /. effect could make the program go wild.... "father father the pool is red and green and cold....." ;)
  • would there be a market for a thing like this?

    somebody could probably package this thing a make a decent buck selling these.

    keep the instructions on line, but market it for your typical joe.

  • Always, and I mean *always* use clickable thumbnails as your primary image.
  • Overkill (Score:4, Interesting)

    by tkrotchko ( 124118 ) on Saturday February 09, 2002 @10:01AM (#2978984) Homepage
    The problem with this system is that its automating something that is more easily handled by cheap mechanical devices. Mechanical autochlorinator technology is cheap and works.

    Most people think a pool with too much chlorine will have a "chlorine" smell and will irritate your eyes. This is a fallacy; pools get that funny smell because the available chlorine has been turned to chloramines. The only way to get rid of the chloramines is to add more chlorine. So ironically, a "chlorine" smell in a pool is a sign of poor maintence and NOT ENOUGH CHLORINE! Your eyes will not be irritated, your skin won't turn red, you won't be harmed by too much chlorine in a pool.

    Besides this is attacking the wrong problem. Keeping the proper chlorine levels in a pool with the proper chemistry is simple. Combined with the mechnical device I've already mentioned makes checking the chlorine levels a once-a-week chore for a residential pool. Its the least bothersome part of running a pool.

    The tricky part is the rest of the chemistry (particularly total alkalinity and pH). It can be done via automation, but there's no particular need to have a computer do it. Again, its a once-a-week check, and then you add small doses of chemicals at that time if it needs to be balanced. But the balance is critical to everything about the pool and the health of the people in it.

    The bottom line is that you have to check it once a week yourself anyway, regardless of the automation system. Spend your time swimming, not inventing the equivalent of an electric dog polisher.
    • I agree with you that his Linux device is overkill, but I disagree about the affects of too much chlorine. Many people are simply intolerant or allergic to it. We've been using Baquacil, which is a hydrogen peroxide/organic disenfectant based system. We get many reports from people that they didn't know smimming in a pool could be so comfortable without the irritation and smell of chlorine.
      • Re:Overkill (Score:3, Informative)

        by tkrotchko ( 124118 )
        In my experience, people who say this are intolerent to bad pH balance or chloramines. I've had people tell me that "they can't tolerate chlorine", and tell me my pool hardly has any chlorine.

        The truth is, I keep my pool chlorine levels relatively high. The trick is proper pH balance.

        Incidentally, I don't have any experience with Bacquil, but the people who I know that use it, I never like the clarity of the water.

        That's not a knock on anything, everybody keeps their pool the way they like it; we've been happy with chlorine (in fact, I had the ozone generator removed because I'm convinced residential ozone generators are useless).

        Pool season in only 3 1/2 months. Can't wait.
        • Was a salt-water pool. The filtration/cleaning system was electrical based, and super simple looking and small to boot. The water was VERY gentle, you could easily open your eyes underwater without any burning, and when you got out, you weren't "sticky".

          Now, true - maybe a chlorine pool can be the same way with proper care and attention to everything - I don't know, I have never owned a pool. But I tell you, the cost in savings of chemicals alone for a salt water pool make it seem worth it (basically, you use big bags of salt, and a bit of electricity - cheap).
          • An interesting thing that I've learned...the chemicals are the least expensive part of running a pool. The most expensive part (aside from equipment repairs) is the cost of electricity to run pumps. That adds about $40-60 a month in the summer.
            • True, I would have to concede that running the pump is the most expensive thing, and you don't get away from that with a salt-water pool. I tend to wonder, though, whether you have to run a salt-water pool pump more or less? Would be something interesting and worthwhile to know, to say the least.

              Still, the advantages of simple salt over pool chemicals still make sense, if only for the simple reason that one is safer (overall - storage, transport, use) than the other (chlorine/acid vs salt)...
  • After all, houses with pools generally don't sell for much less than half a million, so if you can afford something like that you can afford to hire a human to do the work of cleaning it for you (hell, you can probably afford to hire an army of topless models to do the cleaning for you!).
    • After all, houses with pools generally don't sell for much less than half a million,

      You must be in the Bay Area...
      In the rest of the country (US), this isn't the case. You can buy a house with an outdoor pool for about $250K on average in "normal" areas.
      • Hell, here in Phoenix, it is even possible to do it for less - ok, maybe the house and pool aren't new, but tommorow I will be looking at a 3 bdr house w/covered RV parking, covered patio, and diving pool (ie, pool with 10 foot deep end) - and it is selling for "only" $120,000!!!
  • Wheel re-invention (Score:2, Insightful)

    by gruntvald ( 22203 )
    When I got to the first part about not using X10, and making his own controller, (despite crud complaints about X10 stuff not being made for high voltages), I gave him the benefit of the doubt. When I got to the next part about not using a basic stamp either, I figured we were at the wheel re-invention stage, and lost interest. Not only that, it doesn't use sensors for chemical level detection ... oh well. However, this kind of stuff always has the potential for interest - folks - you might like homepower magazine too - especially if you live are being shafted by California power policies right now!
  • There are lots of programs out there now that remind you when things need to be done in an aquarium -- but this kind of thing (not the one on his site, that's still open loop, it just acts on faith that the chemicals its adding are actually needed) would be very useful in aquarium maintenance, especially marine/reef aquariums. You could set up pH, specific gravity, etc... meters and based on those add chemicals and fresh water. Or you could run all those tests manually and have the system add the appropriate amounts based on the numbers you feed it. I'm sure large public aquariums run systems like this to keep things in check, but it would be cool to do it at home.
  • I believe his little server croaked.
  • Well, I got there too late...guess the guy doesn't read slashdot - here's all his site says:
    Swimming pool control with Linux
    Something happened Saturday, February 9, 2002, resulting in this Web site getting hammered with hits and overloading the server. Why is my site
    getting 10,000s of hits this morning?
    Was there a provocative link posted somewhere?
    Please someone email me about this at:
    Richard J. Kinch

    Guess the guy's mailbox is gonna get full now, too...hehe
  • Swimming pool control with Linux
    Something happened Saturday, February 9, 2002, resulting in this Web site getting hammered with hits and overloading the server. Why is my site getting 10,000s of hits this morning?
    Was there a provocative link posted somewhere?
    Please someone email me about this at:
    address deleted
    Richard J. Kinch
  • I wonder if I can do this with my aquariums? It would be nice to have the pH, ammonia, nitrites and nitrates, Kh and GK automagically measured or easily accessable. Rather than having to use drops for each test.
  • Pool::Clean

    that module has saved me hours of icky pool cleaning. Thank you CPAN!
  • by Old Wolf ( 56093 )
    ...a Beowulf cluster of swimming pools?

    The hydroslide could autoswitch to whichever pool had the fewest people in it
  • Micro and Mini PLCs (Programmable Logic Controllers) would be appropriate for an application like this and are very inexpensive with the added benefit of being able to run 24/7 without ever needing reboots or kernel updates, etc.

    They can be programmed very easily with ladder-logic programs (basically large chunks of IF a AND b OR c TURN x ON/OFF) and already have built-in timers and counters that make an app like this as easy as pie.

    A microPLC like a Mitsubishi Alpha [] with 4 inputs/2 relay outputs is about $85 and $110 for 6 inputs / 4 relay outputs.
  • ... the gene pool?

    Too bad we cant have a linux box control that ;-)

  • I want to see the pictures !!!
  • Kinda makes those $800 NASA toliet seats look like a sweet deal. Wouldn't a $1.50 PIC do about the same thing and allow the purchase of $998.50 worth of cold, frosty beer?

Each new user of a new system uncovers a new class of bugs. -- Kernighan