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Topic: Toilet Flushing Recognition (Read 9508 times) previous topic - next topic


A microphone can work, I wouldn't drop that idea. The noise is strong it depends where you put the mic. Even a piezo should work as the flush should generate considerable vibrations. Flushing is also a time factos. So a simple cough should not trigger that (a long vomit  :smiley-mr-green: might). You don't need an FFT in that case, simple filters could do the trick if needed.

Another option is a pressure sensor, flushing will surely change pressure in many points...


My MIC already has band pass filter (pass band 100Hz 10KHz)

as in the last post I already mentioned, length of a flush is long. You could use 3 band pass filters on various frequencies so you distinct between various noises (to me a flush sounds pretty much white noise, so you should have signals on all of them, other rumors might/should be pretty short  and have distinct frequencies, ok, add a sign that says: don't sing). Use a moving average filter on a subsampled part of the output as they are very efficient (byte as resolution for the array should be more than enough). I also don't think you need a fast sampling rate, 1-2Khz could do the trick, maybe even lower.

I have a filter design suite on my website (choose 1st order filters, long calculations not float): http://www.schwietering.com/jayduino/filtuino/


I sort of started looking at this but then when on to something else


I did attach a piezo for a bit to my main line - and felt that I could get an indication when different water sources were on - I also got noise from walking across the wood floors but the profiles were different.

the following might also give you some ideas




There are some really good electronics tutorials here:

Passive RC high pass filters


Passive RC high low filters


He explains, he demonstrates, he shows the theory and the calculations, and he has a cat!
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

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