Washing machine ended beep detection?

Setup, Configuration and Use Scripts & Rules
1

Hi, did anyone try to detect washing machine or dryer emd sound with OpenHAB?
My raspberry Pi running the OH is in the same room with those machines so I thought it might be good idea to do it that way. The machine emits characreristical tone when ended.
I tried to search but I didn’t find anything similar on this forum. I am aware of the solutions that use power meters.

Thanks

2

Besides power meters/plugs, you could use microphones on the Pi (?) or maybe better a DIY ESP to detect noises, example.

3

I would still suggest you do this with a power plug, zigbee, zwave or similar.
I have an add-on that makes this easier, it also possible to do the logic.yourself in rules.

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4

Maybe you could hook up something like this? Sound Detector Hookup Guide - learn.sparkfun.com I’ve never tried it, but it looks interesting. You might prefer a tone detector, not a sound detector, but this one looks simple and cheap and might be worth a try.

5

This may be a start:

But unless you use something which can filter out the exact frequencies you’re looking for, and match those up to a pattern that you’re looking for, then it’ll be difficult to drown out other noises.

I really like the idea, though - using one device to sense two devices. But it’d be too much faff for me - I’d just stick a power sensor inline on the power cable and call it a day.

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6

Thanks @chrismast, I had a look but I don’t think that is what I am looking for. I would need to detect the sound tone pattern, not just the noise. Sound detection only might for example detect the centrifuge noise and trigger the output.

@Seaside, I know that addon, I already use it.

7

Yes, the laundry room can get noisy so false triggers can be expected unless there is detection of the chime tone

I would probably go that way too

8

I think I’ve heard of people using vibration sensors, but have no experience with them myself.

I’d also just go with a power sensor, unless you’re just doing it for the fun and adventure. :wink:

9

You can actually detect sound patterns via code, but I agree with the previous posters, power meters are way easier. Would go the DIY way if you want to learn and tinker only.

10

The tone is much more interesting than the power meter. Look at this: Sound Whistle Tone Frequency Picker LM567 - ElectroDragon. It’s based on the LM567 (an old National part since acquired by TI). You can find some info around the web. Look at this: Tone Detector

Now, we are assuming that the “tone” your washing machine makes is a single frequency or close to it. The circuit above will be looking for a single frequency. That’s probably good enough.

This is not the easiest route to a solution, but I think it’s more fun if you have the time.

I’ll bet you can find many, many other tone detector solutions as you search the web.

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11

Darko said that it’s a pattern, so I don’t think it’s a single tone/frequency.

12

Just set the threshold of the dBmeter to a higher value.
If the dBmeter is close to the beeper, it works. Just look at the received values.

13

Thanks for the suggestions. I agree that would be interesting to try to detect the chime, but unfortunately I don’t have the time and knowledge (which again corresponds to time to learn something new), so I will go the power meter way for now.
To clarify, my idea was to check if it was posible to connect a microphone to the rPi audio input and try to detect the chime, similar to how “Ok Google” is triggering the smart speaker, and communicate that to OpenHAB somehow. (Although at this moment I am not even sure that the 3.5mm connection has mic input, never tried it)

14

Thank you for this! I’ve been toying around with my power plug for my dishwasher and for now just have a simple timer for (longest program)-minutes after power on spike. This is so much better :slight_smile:

15

Hi Darko,
very good input. I also thought about this connection. Reason is that I’m baking bread and my oven talks to me with several sound patterns but unfortunately the kitchen is far away from my home office so I can’t hear it which leads to sometimes dark bread (also good). So I’m looking for a solution to analyse the sounds and tranfer it into messages … and like you I’m not the real IT-specialist …

16

The sensor data could be scraped from the sensor web page or maybe use the api request, if available for the sensor. API is available for ‘pro’ sensors. I use both methods for many other technoline mobile alerts sensors.

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