Garage status monitor

Garage status monitor

Jody Farr’s garage status monitor, his very first ‘real’ project, was borne out of necessity:

In the middle of July, I was wondering why the air conditioner in the house wasn’t keeping up. I must have spent hours looking things over, making sure the compressor was working, replacing filters, blah blah blah. After a while, I found myself standing downstairs in the middle of my garage and it hit me.

The garage door had been open all day. This was the reason why the ductwork was sweating and the cement floor looked damp, and probably a big contributor to the air conditioning problem. From the main floor of the house, it’s impossible to tell if the garage door is open, and with a 5-year-old always going out to ride her bike, you can bet it’s open more often than not.

And that’s when I decided it was time to find a way to build a gadget to let me know.

A TMP36 temperature sensor, XBee, and roller contact switch later, Jody had a system that sent the garage status to his computer. Nice going!

10 thoughts on “Garage status monitor

  1. erasei says:

    I did this same thing using an X10 cm11a transceiver and used 2 DS10A wireless door/window sensors.. one for each of my garage doors. I use the open source ‘heyu’ engine to control the system.

    I mostly use mine as notifiers when arming the system at night to tell me if I left the garage door open so that I can close it before going to bed.

    I also use the same sensor on the interior door that leads to the garage. It doesn’t always latch and I have two curious cats who could easily get into something they shouldn’t in the garage, so this sensor triggers a script when the door opens, and if the door has not closed in 30 seconds it triggers an alert to the whole house (a lady saying ‘Garage Door Open’ over and over until the door is closed).

  2. wonder-wheeler says:

    Most building codes require that the door between the dwelling and garage be self closing! Maybe someone removed the spring hinge from the door?

    The building codes recognize that fires occur in garages and that the door should not be left open due to gasoline fumes, exhaust gasses, and the passage of fire. Also, the wall typically has special sheetrock to slow the passage of fire, and a solid core door is specified for that wall. They want the wall to last an hour and the door to last about 20 minutes. No cat doors allowed…

    1. GanadoRH says:

      Goodness gracious! Your building codes are SERIOUS. We’re doing good to have houses with garages here. That is an awful lot of government MUSTS in your builders’ faces. Where do you live?

  3. otterson says:

    I did this with a LED, resistor, and alarm system magnetic reed switch. I robbed the power off the door pushbutton wiring. Cost? less than $3. Mostly for wire.

  4. refreshh says:

    I’m impressed with the gadgetry, but not convinced it’s the best solution. In addition to the building codes mentioned above, I am concerned about thermal and pressure boundary that should be between your living space and the attached garage. The garage should be outside and separated as such. The connecting walls and other boundary elements (including the ducts, which really shouldn’t be in the garage anyway) should be insulated and air-sealed just as you would other exterior boundaries. The door closer and other code issues are mainly concerned with minimal fire safety.

    If you use the garage for cars or lawnmowers or storage of chemicals, etc., then you don’t want the fumes and combustion byproducts to infiltrate your living/conditioned space. I could go on with the rant, but will spare you. I encourage you to consider a decent energy audit that includes pressure diagnostics on the garage and ducts.

    Additionally, $5 says your AC is actually over-sized and not able to effectively dehumidify. Or the refrigerant charge may be incorrect.

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My interests include writing, electronics, RPGs, scifi, hackers & hackerspaces, 3D printing, building sets & toys. @johnbaichtal

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