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Am I Hot or Not 102

Posted by krow from the electric-dreams dept.
Sure, it's not the dream system with computer-controlled vents on the furnace and a genetic algorithm to optimize heat-flow, but it is pretty damn cool. This system makes use of Dallas Semiconductor Digital Thermometers to monitor temperature throughout the house. Hopefully the fellow running the project will put up the source to the Linux driver he has running the sensors. This project ties in nicely with the question posed by a recent Ask Slashdot as well.
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Am I Hot or Not More

Am I Hot or Not

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  • why is this new technology (Score:3, Interesting)

    by crystalplague ( 547876 ) on Saturday July 06, 2002 @03:48PM (#3833917)
    I've always wondered why thie hasn't existed for a long time already. All you need is a thermostat for each room and a servo controlled baffle for the vents in that room. Upstairs hotter than down? Close downstairs baffles a little...problem solved. This is hardly innovative technology.
    • Because it is more complicated than it seems. Just one simple fact: if you close the dampers too much, the inside coil will freeze. Why? Now, the answer is not obvious...

  • Developers: Am I Hot Or Not (Score:5, Funny)

    by Craig Maloney ( 1104 ) on Saturday July 06, 2002 @03:48PM (#3833920) Homepage
    Whew... For a moment from the title I thought it might have been a competition amongst developers to determine if they were Hot or Not. I don't think a lot of the egos out there could take that kind of abuse.
  • When I saw the title I thought some of the Slashdot editors posted their pics on this site.

  • Heh. (Score:3, Funny)

    by Skreech ( 131543 ) on Saturday July 06, 2002 @03:50PM (#3833930)

    Frankie is a Radisys EP-32 with a 33Mhz 486DX, a megs of flash memory, and 16 megs of EDO RAM. Of course he boots Linux directly from the flash disk.

    I hope thats not the webserver! Otherwise, I belive the answer is "hot."

  • Oh, come on.... (Score:5, Interesting)

    by SlashChick ( 544252 ) <erica@eriGINSBERGca.biz minus poet> on Saturday July 06, 2002 @03:52PM (#3833939) Homepage Journal
    You can't have an article entitled "Am I Hot Or Not" without having a link to the real Am I Hot Or Not [hotornot.com] page! Who wants to look at thermometers when you can look at real people and rate how "hot" they are based on a completely shallow judgement?!
  • I would like to see a system that attaches to the back of your computers and uses the heat energy to heat to house. Why extra furnace bills to keep the room that your thermostat warm with natural gas when a couple P4's running a web server will work?

    Just a thought, after all we should be lowering our need of Fossil Fuels

    Medevo
    • "I would like to see a system that attaches to the back of your computers and uses the heat energy to heat to house."

      It's called a fan. Most systems include that feature. Where you direct the warm air is up to you.

      Many people do overrate the actual amount of heat generated. If your power supply is less than 1,000 watts, you can't even create as much heat as a toaster. Just a furnace fan uses 750 watts [doe.gov]. An electric furnace is 8,500 watts [snopud.com].

      And those aren't "fossil" fuels, they're abiogenic [cornell.edu] except for coal. It's not a matter of using it all, it's a matter of whether we use it faster than it trickles up.

  • It'll be hotter when it's done I suspect... (Score:4, Insightful)

    by MrIcee ( 550834 ) on Saturday July 06, 2002 @03:56PM (#3833958) Homepage
    The web page is sorely lacking in details other than a wishlist. Though the two sensors do appear to update in realtime.

    The project is a great idea, but I would have rather the post had waited until the designer had actually done the computer controlled vents. I would certainly like to see what vents he chose, and any problems he had hooking them up.

    I also wonder about feedback problems in such a design... that is... consider that the house finds some rooms too warm... it closes their vents and other rooms heat up, as this occurs it oscilates between the rooms and vents opening and closing. Obviously this could be tweazed, but what is the electrical overhead. Where I live, electricity is extremely expensive and so it would be questionable if such a design would be cost effective.

    It would also be nice to have variable vents, that is, vents that could be selectivly opened a certain amount (which would reduce the feedback problem).

    Of course, here on the Island our problem is not heat control, it's dampness and channeling of tradewinds through the house - so I wonder what the possibilities of a computer controlled window screen would be, with moisture and wind sensors (probably motorized louvered windows).

    Ah well, nice idea but it seems a bit premature for a solid slashdot discussion.

    • ;)

      My vents *are* computer controlled, and they're variable ;) Moreover, the A/C unit itself can be controlled.

      See my other post for the URL.
    • It's actually pretty simple as most zoned commercial hvac systems do it. If any of the rooms fall below their preset temp the heating system is turned on and baffles built into the ductwork for those rooms are opened. As each room reaches it's preset temp it's baffle is shut. When all the rooms have reached their individual preset temperatures the main heating unit system turned off. I know sometimes there are problems with the system being overpressurized when too few rooms need heat, a design may need to factor in for this.
  • One of the great ideas to finally come out to the masses. Sure it's been floating around in an unknown amount of people's heads, But for someone to announce and centralise it for those who are interested takes action and will.

    I can see this project helping out those more technically minded in business and the home. Imagine your limited mobile who needs to monitor temperatures all over the house, but can't simply because they can't walk or !

    Definately a plus.

  • I.. (Score:1)

    by outz ( 448278 )
    thought I was gonna get to rate some hotties.

  • Source code is already available - Digitemp (Score:5, Informative)

    by Jess ( 11386 ) <gehinjc @ a l u m .mit.edu> on Saturday July 06, 2002 @03:58PM (#3833971)
    The source code for collecting data from these sensors is already available in a package written by Brian Lane called Digitemp: http://www.brianlane.com/digitemp.php [brianlane.com] I've been using these sensors and digitemp to monitor our computer room temperature [ornl.gov] for the last year. It works flawlessly.

    By the way, the interesting thing about these sensors is that they are actually network devices, each with it's own unique ID. You can address each of them separately over the "1-wire network" and get their temperature reading. Also note, that these sensors directly give you a temperature reading, not current or some other reading. So, they do not require any calibration and are a breeze to use.

    • How difficult did you find it to setup and run? Did you try multiple probes?

      From reading up on the site you mentioned, it looks like they solved the problem using the serial port, while the guy this article is written about used the parrelel port (which gave him the ability to do many probes at once).
      • and is multidrop by design. It's pointless to put each probe on its own bus and design interface circuitry yadda yadda, unless you have so many probes that 750ms to poll each one is too much of a wait.

        That said, a 33MHz machine might not have the UARTs and the speed to handle 115.2kbps data, which is the 1-Wire high-speed rate.

        -jhp

        • 115.2k isn't the data rate. At 115kbaud, the stop bit (or is that start bit?) is just ignored noise and you send either 0x00 or 0xff if you want to send a high or low signal.

          Where I work sells a small micro that hooks up to 4 channels and mounts in a nice rackmount box and sends the data out a 9600 baud serial line. I've got a small program that read teh data, shoves it in /tmp so mrtg can pull it out every 5 minutes. I also know when people leave the computer room door open.
          • 115.2k isn't the data rate. At 115kbaud, the stop bit (or is that start bit?) is just ignored noise and you send either 0x00 or 0xff if you want to send a high or low signal.
            The basic rate for the 1-Wire bus is 14.4kbps. The overdrive rate for the 1-Wire bus is 115.2kbps. Regardless of which speed is used, assuming a 16550 with FIFO high water mark set to 13 bytes, the CPU is still potentially servicing over 1000 very general-purpose interrupts per second, on a none-too-fast machine. If it weren't for the pesky ACK bit one could turn the UART bit rate down to 14.4kbps, easily enough done with an 8250 descendent. These days one may as well use a USB-to-1-Wire bridge. The chip presumably exists or will soon (DS2490, IIRC).
            Where I work sells a small micro that hooks up to 4 channels and mounts in a nice rackmount box and sends the data out a 9600 baud serial line. I've got a small program that read teh data, shoves it in /tmp so mrtg can pull it out every 5 minutes. I also know when people leave the computer room door open.
            That's not so bad. I almost wrote code for a PIC to do some basic 1-Wire stuff but couldn't find great code to handle the bus and had to roll up my electronics workbench rather hastily due to a sudden lack of rent money. A friend of mine had his whole house 1-Wired for temperature based on a slightly more powerful machine in the 486 family. I wonder if he's gotten around to implementing control yet -- he had a handful of DS2406 switches but was pretty much incompetent with a soldering iron.

            -jhp

        • You don't have to wait 750ms for each, just issue a skip rom command followed by a start conversion. They will all convert simultaneously and you then get the data from each one at a time (which is very quick).
      • I am using 4 sensors now, but you can use many more (I'm not sure of the precise limit). The 1-wire network allows me to get readings from all of the probes with out any problem.
      • Dallas Semiconductor is the manufacturer/inventor of the 1-Wire network. Take a look at www.ibutton.com [ibutton.com] for a bunch of different devices. The iButtons are 1-Wire devices in a metal can, some can read temperatures and others can be used for access control. Dallas/Maxim [maxim-ic.com] has other 1-Wire devices that are not in a can, these are the ones that I use for my DigiTemp kits.

        There are serial and parallel port adapters available (from iButton.com or from me in my Basic DigiTemp kit which uses the serial adapter), but the bus itself can be extended pretty far. Using cat-5 cable there are people with 300m runs I believe. The theoretical limit to the number of sensors on one 1-Wire lan is unlimited, they are digital device with a 64 bit unique serial number so that they can be individually addressed.

        Brian
    • I've got a stack that I wrote and have been using for a few years without a problem...well, until 0325 this morning when a battery in one of my thermometer servers caused the machine to fail. It does a lot of cool stuff, including some cool multicast action for plug-n-play data collection and stuff. You can see some good examples here:

      http://bleu.west.spy.net/~dustin/projects/ibutton. xtp [spy.net]

    • Thanks for the mention. Don't forget that there is a whole series of different devices that can be attached to the network, including a weather station (which I just re-connected yesterday), humidity and barometric pressure sensors, Java iButtons, etc. I don't support pressure or humidity yes, but it will be added soon.

      IMHO the site referred to in the article is pretty sparse, except for the diagram of the house. I use RRD to graph all my sensors, as well as the traffic to my webserver -- I'd been wondering why traffic had jumped today.

      Brian
  • Brian Lane [brianlane.com] has made public drivers for these nice Dallas Semiconductors [dalsemi.com] temperature sensors. The software can be loaded from here [brianlane.com].

    --jarkko
  • A DoS attack launched at his thermometer server at the right time (when the heater is on) will raise his electric bill and cause serious personal discomfort. This could be the best DoS attack yet.
  • that I was not the only one doing something like this. Oh well, too late, but here's the link:

    DIY Zoning [sourceforge.net]

  • Am I Geek Or Not? (Score:3, Funny)

    by KILNA ( 536949 ) <kilna@kilna.com> on Saturday July 06, 2002 @04:13PM (#3834022) Homepage Journal

    Am I Geek Or Not [amigeekornot.com]

    'Nuff said. I claim no affiliation with this site.

  • Temperature of my basement (without Linux) (Score:3, Interesting)

    by asmithmd1 ( 239950 ) on Saturday July 06, 2002 @04:16PM (#3834043) Homepage Journal
    You don't need a full blown PC just to monitor the temperature and control a couple of motors. My [151.196.183.167] RCM 2200 [rabbitsemiconductor.com] does this task for just $55

    • That small computer is cool and all, but what this guy did (and its not unique) is use the ultra cheap dallas semi conductor 1-wire chips. Which for around 10 bucks for the controller and 4 bucks in parts for each sensor is way cost effective compared to your 55 dollar single unit sensor. And the dallas units are not limited to strictly temperature sensors either. You can get humidity and dew point sensors also.

      Here is a better site that is along the same lines.
      http://www.garyga.com/OCX/default.htm

    • Very cool web-etech-a-sketch.

      I might as well plug my weather page. Nothing inovative, but it was fun to do.

      http://www.fperkins.com/weather/

  • A few years back. It was mainly designed to control automatic horse feeders, but it also controlled HVAC, generator, etc. Web Page [certsoft.com]
  • Monte Carlo methods like genetic algorithms are usually the last resort for the clueless to get some kind of solution for an optimization problem.

  • Do this for retail food stores and you'll be rich (Score:2, Interesting)

    by Anonymous Coward
    I had envisioned something like this for my family's grocery store. We had three beverage refrigerator cases, one dairy case, one retail freezer case, two walk-in boxes, three 8 foot refridgerated display cases, three air conditioners, tons of flourescent lighting, slicing machines, cheese grater, coffee machine, and much more. The electric cost was over $2000 per month in the summer. Another relative had a retail seafood store, with freezers, ice machines, display cases, etc. His bill was over $10,000 per month in summer. This is in NYC.

    If I had some way of regulating temperature with temperature sensors, and monitored by a computer, turning fans on and off by computer regulation, I could easily have run ducting between the three display cases as one zone, the three refridgerated beverage cases as a second zone, the dairy case and one walk-in box as another zone, etc. I could have turned off the smaller beverage cases, and the bigger one at night (we did some of this by extending the defrost cycle at night). During the winter, I would have like to pipe in cold (below 36 or so degrees) air from outside into refridgerators. By shutting down beverage cases that had compressors mounted under case (instead of in basement like other cases), we would need less cooling (3 ton, 1 ton, 1 ton air conditioners), and we could have reduced peak usage.

    For those of you who know about demand meters and large electricity users in NYC, you know what I am talking about. For those that don't, I estimate that I could have knocked off about $600-$800 from the electric bill monthly in summer, and a couple hundred per month in winter/spring. My relative with seafood store was able to cut $5,000 off of his electric bill by shutting down one freezer and one ice machine. Had he implemented a system like I'm envisioning, I estimate he could have knocked off $4,000, and still retain use of all his equipment.

    The system could be made very simple. For beverage cases, display cases, small walk-in boxes, etc., all that is needed is simple flexible 4" ducting, with small fans placed within ends to push/pull air. The fans can even be powered through the computer, since the sensor wiring would go there anyway. Or powered by the display cases, where electric outlets are normally available, if using wireless to talk to computer.

    Common sense and experimentation would show you where/how to place ducting and fans. I know this would work because we've done something similar on multiple occasions when a display case went down, and freon was hard to locate. It always worked, but without the computer and temperature sensors. We had to carefully eyeball thermometers, and manually turn fans on/off as needed.

    Someone who writes the code to run a computer/temp sensors/fans with a system described above, and goes into the field and installs something like this can make some good money. Businesses may be skeptical at first, but when you mention saving electricity, watch their eyes open up.

    It would take some effort, but hopefully a geek has a grocery store owner in the family that can try this out. Be aware that dairy/cheese/frozen spoils, and you may only be given the go-ahead with beverage cases only.

    System should include dial up or beeper or internet notification if the system or a sensor/fan goes down overnight, alarms for overheated cases, etc. Be aware for dial up that burglary alarm will grab line if triggered, etc.
    System should also be configurable/managed through dial-up or internet. Forget billing for field visits for downed computer. You'll be thrown out on your ass the first time you present the bill due to low margins/profits in industry and coservative nature of grocery store owners.

    Such a system will save considerable money for grocery store (and other heavy refridgeration/HVAC users) owners, and will be something that you can sell if examples are provided, and you LEASE THE SYSTEM, GIVING TIME FOR THE SYSTEM TO PAY FOR ITSELF, or provide financing through monthly payments, while giving the grocery store owner time to see the savings in his electric bills.
    And you'll be helping to save the environment through conservation as well. And I suspect you'll be a celebrity geek in short order.

    Now build it!
    • Someone who writes the code to run a computer/temp sensors/fans with a system described above, and goes into the field and installs something like this can make some good money. Businesses may be skeptical at first, but when you mention saving electricity, watch their eyes open up.

      Howd'ya think companies like Honeywell etc make money??? What you suggest ain't a new concept. They (and others) have been doing it for years...

      I know this coz what youre talkin bout...I do for a living (energy managment small to large business..)

      People can pay for systems with the money they save.... (almost cxost neutral)

  • My how old news becomes new again...

    I have had a Dallas Semiconductor library for Linux available from my FTP site [rongage.org] for about 4-5 years now. Completely open source too. Worked just fine with the DS-1820 and DS-1920 temperature sensors. Heck, I still use it to this day to do temperature checks of equipment.

  • I can't reach the guy's site so I don't know if he's added custom drivers, but Dalls Semiconductor has Linux development kits and source code for their 1-Wire stuff here [ibutton.com].

  • yeah, slashdot linked a site to this guy's home office ip through dynip.com

    and they thought it would stay up?

    he's prolly going to get kicked off his isp for running a server, or even a whole house fully wired with censors has to be against the isp's eula somehow.
  • But Is Cindy McCaffrey on it?

  • server is slashdotted i hope he's not dead (Score:1, Funny)

    by Anonymous Coward
    Jeeze, we've slashdotted the sensor already.

    I hope we didnt end up roasting or freezing the guy.

    this could end up as the first slashdot induced fatality.
  • These devices are available from lots of electronics suppliers, such as here [qkits.com], and simply run off a standard serial port.

    I have been monitoring the temperature [cactii.net] inside and outside my house for months using these things. I use a quick perl script [cactii.net] to read these devices from my gateway box, and run RRDtool to graph it.

  • It's fun but nothing new. A company called Spiderplant.com had a pic based 1-wire kit and I ported their stuff to work with Linux 4 or so years ago. I had a script reading temperature sensors (4 of them) placed around the house( and outside ) and based on that data, I'd direct 2 X10 controlled fans to turn on or off. One fan vented the attic and the other vented downstairs into the attic.

    This is very easy to do and very inexpensive. Cool too ( I mean that literally :).

    LoB
  • I set up a similar system using Dallas' TINI [ibutton.com] Tiny InterNet Interface to poll the temperatures in three parts of my studio apartment: the fridge[1], the hallway to the bathroom, and the kitchen. On the TINI I ran a server in Java that, under control from any TCP client, would continuously poll the 1-Wire bus and work TTL I/O that was on the TINI sockets board but unpopulated[2]. The client for this was a perl program that polled the TINI, put data into a database[3], and switched a relay on/off which controlled a loud muffin fan[4] based upon the temperature in the main room. I had a servlet on my app server which would draw graphs using gdJava[5] from the database and a JSP which would allow zooming in and out.

    Yes, I agree it was grossly overcomplicated, and if I were doing the same thing today I'd probably have had the TINI post data to the app server instead, so as to cut the perl script out of the loop. But I didn't really trust the TINI as much more than a really smart 1-Wire interface, so in reality I'd probably design with the RS232-based 1-Wire interface card instead, or use a PIC to do all this. :-)

    -jhp

    [1] It was a bar fridge and the freezer frequently affected the thermostat due to their closeness. In line with programmer virtue #1, I wanted to wait to defrost until the temperature in the fridge put my food at risk.
    [2] This was my first experience with surface-mount soldering. The new rev of the sockets board has a lot less cool stuff on it now -- the LCD interface is gone, for one.
    [3]The TINI's Java environment wasn't hefty enough to handle PostgreSQL JDBC drivers so something else had to do this.
    [4]It was 2001. I was trying to be nice to the electric grid and my own power bill, even though I was living in a district served by a municipal electric utility. Screw the "right to profit", every town should have one of these.
    [5]RRDtool is for wimps and looks bad too. I had sub-pixel resolution, PNG output and anti-aliased fonts.

  • IRC Channel for Homeautomation. (Score:1, Interesting)

    by Anonymous Coward
    I've just created #homeautomation on irc.openprojects.net for anyone who's interested in having a chat about maybe pooling some resources from our many different individual systems.

    Tangent
  • Rather than use of something like a genetic algoritm,I would recommend that you look at 3-mode (aka PID) control, possibly with auto-tuning. This algorithm has been used industrially for process control for 50+ years, and nobody has really found anything better. The first hardware implementations were pnuematic based analog computers. One of the biggest early applications was to control the massive banks of gas diffusion separators at Oak Ridge for the Manhattan Project. They were critical for this project because it would not have been possible to control this plant using people due to the size of the operation. At the time this was the largest industrial facility ever built. The electrical demands were so large that Oak Ridge could not obtain enough copper for the electrical runs; silver had to be borrowed from the US Treasury.

    http://www.jashaw.com/pid/description.htm

  • monitor my parents chicken shed located a long way frem thier house. I even started a source forge project to write a generic reader and writer of 1 wire devices so I could have multiple apps could read and write to the one wire network. The project stalled due to lack of time, but I think I'll pick it up again some time. The project is called owis, one wire information server, check it out if your interested. Its not real pretty tho, sorta went in the wrong direction, but I learnt abit so it wasn't a complete loss.

    Anyway you can get the sorce code to drive these dohickies from Dallas, can't rememberwhat they call it tho.

  • We did this stuff at a place I worked called AspenTech (http://www.aspentech.com). I think the product is now called "Aspen Plus Online." When I worked on it it was called RT-Opt (Real Time Optimizer). Of course, there we were optimizing entire chemical plants -- say 3000 independant variables in a 250000 equation system. Heating a house would be a pretty trivial optimization problem. Of course Aspen's software cost, say, a quarter million US for an installation (including consulting to customize the plant model). Out of the range of most homeowners, unfortunately. There's tons of chemical engineering literature on these problems, for those interested.

  • What a lot of people here don't get is that you dont need a kick ass processor to do this kind of control

    Most HVAC CPU's in the real world operate with 2-5 Sec cycle times to allow for temp variations etc

    Mind you ....its not as hella cool as a kick ass CPU.......

    So get out that old 386 and turn it into your home zone controller.........

  • Last time my heating's thermostat and clock died, I hade to fork out a respectable amount of cash. At the time I remember thinking that that 486DX-4 in the cellar could be an amusing solution. After all, I can handle electrical wiring, I've seen games ports used as temperature sensors, and I'm a fairly competant hack programmer

    The only problem is that I've absolutely no idea how to switch 240VAC mains with my PC. I usually do things by the seat-of-my-pants, but I don't think this would be too clever with "BIG" electricity.

    So, has anyone got some knowlege and/or experience they could pass along?

  • Misterhouse the Perl home automation system has had the ability to talk to a myriad of sensors including the Dallad Semiconductor Ibutton sensors for a really really long time... Now some guy who recently discovers linux thinks of something neat-o and it get's a slashdot front page story?

    If you want to do the dampers and other things download misterhouse from misterhouse.net it's ready to go.... with a ton more capabilities.

    Home automation is starting to become a mature industry... so someone fooling with a little bit of electronics is not novel, not innovative, and not anything really special except to the braindead sheep that make up the other 50% of the population out there (I actually feel it's more like a 30-70 split.. espically when leaving a concert and the mass-morons cross the street against the light causing traffic to stop.)

    If anyone wants to do this, please do a simple search for linux + home automation on google.. you'll find a plethora of information... I also reccomend researching home automation in general.
  • News for nerds, stuff that... Nevermind.
  • The Dallas Semiconductor "1-wire" bus is actually 2 wires. Power and signal are on one wire, and the other wire is ground. It's usually wired as a twisted pair. You'd think from the name that the "1-wire" bus was some kind of captive RF system, but it's not.

    Thus, the Dallas SemiconductorSecret Decoder Ring [ibutton.com] does require a two-contact connection. It would be more convenient if you could just touch metal to metal and go, for door locks and such. There's a round, socket-like arrangement instead.

    Except for the deceptive name, it's a good technology.

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