Air Freshener Hacking

In an effort to improve his marital standing [Tech B] hacked an air freshener to make it Internet controllable. The main component here is a Glade Sense and Spray. It cost him $7 and is meant to spray out some sweet smells when it senses motion in the room. The unit also has a manual spray button which he patched into with the help of a relay. From there some Arduino code and an IRC bot take over, letting him unleash freshness from anywhere he has IRC access.

When reading about this we were also thinking: “motion sensing circuitry available at local stores for just $7?”. We may have to conduct an investigation into the alternative usefulness of that package.

If you have another brand of automatic freshener around it should be just as easy to hack as this one was.

34 thoughts on “Air Freshener Hacking

  1. Motion sensing is exceptionally simple, you just need to watch the resistance in a pair of photocells for large enough changes, indicating something has past by and disturbed the light level of the area. Putting them behind a fresnel lens will increase sensitivity.

    So basically two CdS cells connected to the analog inputs on a micro will give you motion sensing in your project. So $7 hardly seems like something to be excited about.

    Though pulling the board out and getting it to trigger something else on it’s own might be handy for something very simple and quick.

  2. So all this because “the house stinks when my wife gets home.” Maybe you should figure out why your house stinks in the first place, rather than covering up the odor with nasty chemicals that will coat everything in your house, your lungs, etc?

    For example, open up all the windows and air out the house completely, then close up all the windows and room doors, and see which rooms stink? Maybe you’ve got dead rats in the walls or some food fell into a hidden spot? Maybe you just need to take the trash out more / compost garbage in the back yard / buy a garbage disposal? Maybe the carpets need cleaning?


  3. If the air freshener only uses photoresistors then $7 is a bit expensive if that’s all you want from the device, you can get 4 small PIR sensors from Chinese eBay sellers for $15 including postage.
    In testing I’ve found they can sense you moving two room lengths away easily, and their power usage is extremely low too; 40uA when running and 60uA when triggered. Only drawback is the postage time of about a week or so.

  4. Parallax’s PIR sensor (true IR) is $9.95 at radio shack last I checked.

    Most devices that I’ve taken apart usually consist of an IR emitter and receiver combination. Kinda like an interrupter except the IR transmitter and receiver are both pointed the same direction instead of at each other. When the receiver detects a sufficient amount of IR, it triggers and whatever microcontroller triggers the desired function. The handsfree paper towel machines are less complex and uses a photocell and detect brief changed in light. If the reading’s the same across several readings, it does nothing to prevent killing the batts when someone turns the bathroom light off.

  5. I just put an exhaust on the cat box using a PIR sensor tied to a time delay relay (ELK-960) to drive a fan for 30 minutes after the cat drops a load. works great. It did cost more than $7 though. wife loves it and cares nothing about the aesthetics.

    You can figure out how to build it just from looking at it. It’s real simple.

    check out the finished product if you want (myspace warning)

  6. @StinkyPete

    The house doesn’t stink per say. Its a very old building. We live in an apartment and that musky smell has been here since we moved in.

    I wasn’t after the motion sensing, I was after making the house smell good from an IRC channel. It was to learn.

    Nothing to do with farts lol. But that did give me an idea….

  7. Hey, I’m TechB’s wife. I feel like my housekeeping has been insulted. I clean my heart out in this place. i believe that a lot of what “clean” is, is how it smells. So i am paranoid that my apartment stinks and that if anyone shows up they will think that. There honestly may not even be a smell, besides, if it gave TechB something to hack….why not?

  8. Seriously – hacking is always fun, but a smell in an apartment needs to be addressed in a different way.

    Do these:
    1) Wash (washable) surfaces with a microfiber cloth and household vinegar solution. That (unpleasant) smell will dissipate in a couple of days, but has the potential to transform many smelling compounds into non-smelling ones, and the microfiber picks up the gunk.
    2) Rent a good ozone generator and treat each one of your rooms.

    If these two do not help, you really need to consider moving out before your lungs are full of spores. I have talked to people who lived in rotting houses and their stories are not something you want to experience.

    An unpleasant smell usually signals you shouldn’t be inhaling that. Masking that with something else does not change the fact you shouldn’t be inhaling it. Actually, air fresheners may also contain stuff you do not want to inhale, such as phtalates and polycyclic musks.

  9. Air “fresheners” contain many compounds that are toxins, carcinogens, etc. Best not to be breathing them (or depositing them in your living environment).

    @Tech B. –

    If you have musty odor in building, important to find out why, and try to deal with the source. It could indicate mold, which can be a health hazard also.

    (Not as hacky, but more healthy.)

  10. I made a puppet out of wood, with arms on pivots at the shoulder joint.No legs. I took out the canister. Fixed a small hook into the hole in the mechanism which moves downwards when motion detected. Put the puppet in place and joined the top of the arms together with strong cotton. hooked the mechanism on. When motion is detected, the hook moved downwards and the arms raise up. Had lots of cardboard try-outs to get the best lever mechanism – the attachment point had to be as near the pivot point as possible. had fun anyway!

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