Ultimate garage door monitor

garage door monitor

Want your home automation system to know the exact position of your garage door not just whether it is open or closed? Then the ultimate garage door monitor is for you. There has got to be at least one person that needs that, right? Well for the rest of you it is a handy guide for how-to implement analog sensors (like this potentiometer) into your home automation by way of an analog to digital converter.

[thanks ledtester]


  1. Absolute control!

  2. austin y. says:

    wow, this was (i believe) the closest we have ever come to not having a hack per day. 11:59 is really cutting it close.

  3. bbuuuttt says:

    hackaday almost didn’t have a hack for monday…

    ‘Posted Aug 7, 2006, 11:59 PM ET’

  4. david says:

    Cool, not really seeing a use for it on a garage door, but on other doors that may have varying hights (Dog or human etc) they could be nice…auto open doggie door that opens to human height for me.

  5. Yeah, today was my travel day back from Defcon. I’ve had like an hour of sleep in the last 36, but whatever I should start on tomorrows post.

  6. Arthur says:

    Heh. Your allowed to slip up somtimes eliot. too many people are critical of your site. Screw em.

  7. Thanks arthur, but I doubt most people would give us any slack if we failed to live up to our name ;-)

  8. joe says:

    Unless garage door opener designs have changed in recent years, setting one up is a real PITA since its basically an open-loop control. The opener doesn’t know the position of the trolley, and you have to turn the DOWN and UP knobs and try many times to get it to work right.

    The first company to use closed-loop feedback control on their garage opener, I’ll buy from them. psst..Craftsman, Genie: encode along the chain/screw rail…it’s not hard. There’s only three states to your system, closed, open, or transition.

  9. steve says:

    not realy what i would call a hack but since eliot didnt have much time i suppose its better than nothing at all since am a ex industrial door fitter i know abit about this stuff and find that the most reliable motors .r from a company calld garog in germany also motors from company calld somfy french company these motors have limit swiches that can be set to most hights they all have remote set ups some have a ir interface that can be controld by ur car head lights

  10. theblunderbuss says:

    I would have harped on you guys for not living up to your name.
    Foiled again.

    A very simple hack. I like it.

  11. kyle says:

    I guess its good people are caring about the open/closed state of thier garage before armageddon happens and leaving the garage door open a crack is a bad idea…

  12. OrbnLgnd says:

    Look at this project as an excuse to learn something about feedback, by doing something that is, in the end, somewhat pointless. (not to knock the project at all!) Yeah garage door openers are a pain in the arse to get working. Yeah they are really simple on the electronics. But that is the point. Sure it is a pain for the average Joe to turn some knobs for an hour till the damn thing works right, but it is much more of a pain for the average joe to wrap his head around why the thing acts crazy when the sensor breaks. Manufactures have absolutely no incentive to produce closed loop systems. Why? Because thousands of door openers are sold all across America every month. Production and demand meet at the lowest possible cost for both consumer and producer. If EVERYONE threw out their door openers and demanded something more intelligent, it would get built.
    Let us never forget law number one of engineering for the consumer. KISS!

  13. OrbnLgnd says:

    “not realy what i would call a hack but since eliot didnt have much time i suppose its better than nothing at all since am a ex industrial door fitter i know abit about this stuff …”

    Looking back over the last several hacks, I am certain that it has already been clarified that someone let an [edit] into the club house.

    But damn my curiosity got the best of me: just what constitutes a ‘hack’ in your professional garage door installing opinion? I’d really love to know. I await your enlightenment.

  14. strider_mt2k says:

    How sad is it that not only do these tools _not_ have any good hacks to contribute, but then have to ruin it for those that do?

    Christ, it’s just a website. get a life people!
    Have you ever even kissed a girl?

    Leave hacking to the hackers, and go back to the clowns in clown college.

  15. Harold says:

    I had to build a device that sorted marbles based on color in high school. I designed my entire machine to rotate on a central pivot and feedback on position was given through a potentiometer in a setup very similar to this. My rig was reliable, but my code stunk. Oh well.

  16. ivan256 says:

    Even a fraction of a watt seems like a high cost just to know the exact position of your garage door at all times… Or the transition state of anything that remains in a steady state most of the time for that matter. This would be way better if it sampled periodically and kept the power off most of the time.

  17. chansuke says:

    #15 – I did the same thing last year. Instead of using potentiomers we opted to use switches instead, and it was much more reliable and easy to code.

    Perhaps something similar could be used here?

  18. pretorious says:

    #17- I think the purpose of using a potentiometer is so that you can know the exact position of the door, not just full up or full down. Maybe someone who uses a paint sprayer in their garage would need it part way open? Or maybe in an apartment complex, so the landlord can know if something is preventing the door from closing…

    Good idea if you can think of something else to apply it to as well.

  19. winphreak says:

    just a possible use, but it could be set up to only lift one foot to, say, let animals in and out. there are some uses for setting it to a certain height, I just can’t think of them at the moment.

  20. bp says:

    This is cool though I too am scratching my head a bit about what I would use it for. The pet idea is possible… but beyond that I’m kind of drawing a blank.

    Interesting write up though. I wonder if there are other mechanisms with a similar setup that you could use this as a closed circuit controller for? Like a giant CNC made with garage door openers? Just perfect for when you need to cut a 2:1 model of a car out of foam.

    Hey that’s not a bad idea….

  21. Pedro says:

    ok, call me crazy but what about a CNC hot-wire cutter? a hot wire is lifted up and down while a block of foam – mounted on a turntable – is moved forwards and backwards.

    not a great system for intricate details but prototyping bodywork, aerodynamic shapes, regular shapes/prisms should be ok…

    or hey, just make your home automation system a little flashier. ;)

  22. Freiheit says:

    RE: power consumption.

    Should be simple to have it poll when you ask the controller, “where is the door”?

    It would be equally simple to have it tie into a logger that would trigger a poll event when the garage door moves.

  23. sammy says:

    I leave my garage door cracked to help cool it down when I return home. I live in FL and the garage faces south. Leaving it open some really helps. I agree with the post above about using a fraction of a watt would be wasteful. You should be able to put an inline 110VAC switch at the bottom of the garage travel to interrupt power to the wall wart and reduce this consumption. My garage is closed fully about 90% of the time. A problem if your circuit ever fails and the automation system sees 0 volts as door closed.

  24. ravuya says:

    Ooh, I’m seeing definite evil potential in an analogue remote control for my garage door.

    Stand out on my front lawn and wave something with an accelerometer around to control it from afar.

  25. bEN JACKSON says:

    a 100 ohm pot is going to use WAY too much current for this sort of thing. this would work fine with a 10k pot and use 1/100th the power. otherwise it’s a neat idea.

  26. jaded says:

    If you’re interested in seeing a garage door open a “crack” or “just enough for Fido”, adding a simple magnetic reed switch when the door is open by the desired amount is a simpler solution. That could even be tied into your alarm system as a “closed” position (assuming the crack is for ventilation and not a dog.)

    Two things to watch out for when doing this project:

    1: Safety. Garage door springs store a tremendous amount of energy. If you loosen the wrong bolt, you could be unleashing a instantly snapping steel pole and cable. If it doesn’t break bones in your hand, you’ll be lucky. (I was lucky!)

    2: Security. If you leave your door open more than a crack, a criminal can lift the door by pushing hard and reversing the motor. (Worm drives are not at risk.) The only thing holding your door closed is friction. You may have noticed most openers have a J shaped bar to connect the travelling part of the opener to the door. The J shape allows the trolley to get closer to the front of the garage, helping prevent this attack. Leaving the door open even a crack slides the trolley way back, giving the thief leverage.

  27. John Smith says:

    I am a former engineer of Chamberlain (the worlds largest garage door opener manufacturer).

    Though unknown to most people, Chamberlain openers actually have a serial interface. Door position (as well as much other data) can be easily obtained via the interface.

    -real idenity withheld (Chamberlain is a big, powerful company).

  28. julio says:

    John ‘Chamberlain’ Smith,

    I would love to uncover a way to determine from inside my home if my door is open or closed. I have a garage that is not attached to my house and I have found it open many times leaving for work in the morning. Good thing it is a safe neighborhood or those shiny new golf clubs would have been gone.

    Any ideas anyone??

    I do have a chamberlain

  29. julio says:

    John ‘Chamberlain’ Smith,

    I would love to uncover a way to determine from inside my home if my door is open or closed. I have a garage that is not attached to my house and I have found it open many times leaving for work in the morning. Good thing it is a safe neighborhood or those shiny new golf clubs would have been gone.

    Any ideas anyone??

    I do have a chamberlain

  30. jaded says:


    You want something like the Liftmaster 915LM: http://froogle.google.com/froogle?q=Liftmaster+915LM&lmode=online&scoring=p
    It’s a stick-on tilt-switch transmitter and a reciever with a red and green light. You just stick the sensor on the top panel of your garage door, and plug the receiver in wherever you want.

    When the door is fully closed, the receiver’s light glows steady green. When the door is open even a little bit, it flashes red.

    I’ve had one that was shipped with my Sears garage door opener for about three years now, and I really like it. And I only have to replace the coin-sized sensor battery about once a year.


  31. John Smith says:

    i suggest using the remote sensor mentioned in post 30.

    For more information on the serial interface, look into this product:


    its the motion detector that turns the light on and off. think about it, the only way this detector can work properly is if it knows the current state of the light. it determines this with the serial interface.

    -john smith

  32. nds-flash says:

    could set it all up so that doors open just enough to get the car in and if a wrong code is entered too bad your roof is gone.

  33. hybrid reviews says:

    When I die, bury me on the golf course so my husband will visit

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