Odor Detect Switch

I recently bought this Odor detect air freshener:
http://www.amazon.com/Air-Wick-Freshmatic-Automatic-Freshener/dp/B0084JEH3K
 
It actually came out a few years ago, and now you can buy them for very cheap if your local grocery store still carries them. 
 
This freshener sprays every so often, but if it detects odors it puts out a double spray.  I thought this was just hype, and how could a device running on two AA batteries for so cheap actually work? We'll surprisingly it does work.  In every case it quickly detected the problem and neutralized it, so-to-speak. 
 
So that got me thinking, if they could make a bath fan switch like this, that would be great, but I've never been able to find one.  Has anyone ever seen such a switch?  I've come across a few sensors for commercial rest rooms like this, but none that I could easily use.

You could probably get in there and hack the guts of that thing, tie it into a relay that sends a signal to a controller or something like a UPB link.
Probably would not be that hard.
Use the 12VDC power supply for the relay and drop it down to the 3VDC to operate the brains of that thing.
There may even be a relay output inside that activates a solenoid to spray the air freshener.
 
 
 
I just use my wife as an odor detector...

Desert_AIP said:

I just use my wife as an odor detector...

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You have a good point there. I could use voice recognition. 
 
I actually wired one of these to be triggered by a float in the toilet, so for every flush it would spray, but when I noticed how good this device actually worked, I thought there might be a better way.
 
The Air Wick device uses a sensor that is pretty cheap and easy. I think it just has 4 pins. Two for power, and two for a resistance that changes with the odor level.  The problem is how to easily take this and create a switch that meets electrical codes?  Even the dispenser is not great because it also sprays every XX minutes, and you can't shut that off. Obviously they want to sell as many refills as possible. If you only sprayed for hi-odor times, the can would last for months if not years. They design these sprayers so its pretty hard to hack them. 

A few weeks back I was looking at this "Natural Gas Sensor" on SparkFun which detects Methane for a similar project. It turns out somebody used it to make a fart detector and tweet the "events" for the world to see... http://www.instructables.com/id/The-Twittering-Office-Chair/
 
Terry

roussell said:

A few weeks back I was looking at this "Natural Gas Sensor" on SparkFun which detects Methane for a similar project. It turns out somebody used it to make a fart detector and tweet the "events" for the world to see... http://www.instructables.com/id/The-Twittering-Office-Chair/
 
Terry

Click to expand...

That does finally prove that Twitter is good for something.

The sensor the Air Wick unit uses is made by AppliedSensor and detects methane. It is claimed to have very long life and it uses very little power. I'm guessing they cost under $2. AppliedSensor makes many air quality sensors used in automobiles and other places.
 
Here is another..
http://www.figarosensor.com/products/2611pdf.pdf

ano said:

That does finally prove that Twitter is good for something.

Click to expand...

 
It also proves that fart jokes will never get old.