Electronics That Tell You To Wash The Dishes

Nothing stinks up the house like a sink full of dirty dish. Well, a full trash can will do it to a greater extent, but that’s a project for another day. In what must be an overreaction to a perpetually full sink of dishes at his London Hackerspace, [Tom] built a web-connected dirty dish detector.

He calls it the Great OpenCV Wash-Up Detector. The system features a series of different signals to ‘remind’ forgetful geeks about cleaning up after themselves. The initial implementation uses a traffic signal to alert the room that there are dirty dished to be cleaned; illuminating the different colors to show how long the sink has been full. [Tom] also plans to add message bursts to the IRC room, and air horns when the situation gets dire.

As the name implies, this uses OpenCV to detect circles in the sink. A webcam has been mounted above it pointing straight down, providing a clear input image to detect plates, mugs, and the like. [Tom] even wrote some code that disables the system when the lights are turned off.

Of course, this may train offenders to leave the dishes on the counter where the detector can’t see them.

25 thoughts on “Electronics That Tell You To Wash The Dishes

  1. I already have one of those, It’s called a dishwasher. when you cant put any more in, you throw in a soap glob, close the door and press start.

    Apartment ones that are smaller and hook to the sink are also available for those that dont have a home with one.

    it’s also cheaper than a webcam+computer setup to watch the sink.

  2. What a waste of time and technology. How much free time must people have to work on such ridiculous projects when they could make something that is actually useful?

    I know people will come here shouting that ‘its useful for me’ blah blah and whatever but come on, its a waste of time.

    1. This project seems like simply a good way to explore what OpenCV can do, from the looks of it. OpenCV has quite a learning curve for those unfamiliar with image processing and recognition algorithms, so it takes practice to what whats right for each application. This is just a stepping stone to bigger, more advanced things.

    2. Hey at least I didnt waste my time commenting on someone elses project without producing anything myself.. Please politely show me one of your projects so I can do so


      During this I learnt:
      > how to cross compile and build images for ARM based linux machines (its hosted on a beaglebone and the factory supplied image doesnt work with a ps3eye)
      > How to work with opencv Python bindings (whereas i’d normally c++/openFrameworks it)
      > how hough transforms work (simple answer: screw the doing the math yourself and use the libraries)


      no matter what techy solution you design you cant solve a social problem. You can, however, bring the problem to everyones attention by doing so :)

      1. Tom,

        Thanks for documenting this project and sharing it. I’m a fan of OpenCV and have always wanted to deploy it to an embedded system. Am I correct in understanding that you’ve deployed OpenCV to the Beagle Board? If so, would you be willing to share more information on how you did that?


    3. I’ll admit I had that’s nuts sort of reaction when I saw this. In that hacking is a leisure time activity,I wouldn’t call it a waste of time. No more a waste of time than reading a novel, working on a cross word,Sudoku, jig saw puzzle.

    4. So what? It is an ironic use of technology. And it’s his time to waste. And he’ll go on to do interesting things, and you will be a red-faced middle management type that takes a dookie on everyone else’s good time. Go do something useful and post it.

      1. Well I guess SOMETHING is better than nothing. It’s been a slow news day so at least we have something to read, even if it’s a bit useless. Hopefully he’ll use what he’s learnt to make something useful and then we can all enjoy :)

    5. This isn’t a waste of time, he showed a creative streak in solving a problem, learned some stuff in implementing it and may be able to apply what he learned in future “usefull” projects. People who do such useless stuff usually end up doing quite usefull stuff by and by. Of course I just would have said fuck it and switched to paper plates.

  3. whether it is for the lazy or very stupid.
    there before you really need this system.
    a simple glance at your kitchen work easier.
    what is the next alarm that after you’ve been poo
    you have the toilet flush. come on people think a bit and remember is not difficult

  4. to all the nay sayers – I disagree however you can not truly understanding the problem that this contraption is trying to solve.

    1) Sure it could be solved with good habits.
    2) Sure a dish washer would solve it.
    3) Sure it might seem over engineered.
    4) Sure the components might be expensive.

    …. For a home user.

    BUT remember (as stated in the original article), this project is to deal with a community problem in a public hackspace with ~400 members. So considering this:

    1) 400 odd people with only a small number of dirty/lazy people = big problem to change their habits
    2) Dish washers only work if people have good habits, try teaching 400 people
    3) Social engineering, signs, rules have all failed; the dirty people still leave a significant amount of dishes about the place – a more complicated solution was needed
    4) The components aren’t that expensive when the cost is split across 400 people…..

    1. also it generates a bit of interest in the whole problem, what we found happens now is:

      > people say “hey whats that?” at the lights. we explain to them what its doing and make the problem more known to members in the process = win
      > people look for ways to break it, i’m sure they can (it doesnt detect glasses yet) but with every attempt to break it my learning of CV techniques improves = win
      > people leave stuff on desks instead of the sink, generally other members see this and shout at them = win

      so 3 wins there!

      next stage is to stuff a kinect in there and do things with point clouds instead of edge detections and such

  5. Interesting concept. My co-workers are constantly battling the dirty dishes issue with angry e-mails that do little more than clutter my inbox. Perhaps reading this will help them see the larger problem, and hopefully encourage the offenders to wash their own dirty dishes. One can hope!

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