Find all your DIY electronics in the MakerShed. 3D Printing, Kits, Arduino, Raspberry Pi, Books & more!

I love that this guy’s project blog is called Scoop My Cat Box, and the subtitle is: “One man’s quest to offload his responsibilities onto the internet.” So far, he’s working on two projects, the titular robo cat box, and an Arduino and ultrasonic range-finder-based water dish that lets you know, over the innerwebs, how much is (or isn’t) in your cat’s dish. I love the last line of the video: “In no time, your friends will know exactly how much you neglect your cat.”

Ultrasonic cat dish

Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of a dozen books on technology, DIY, and geek culture, including the first book about the web (Mosaic Quick Tour) and the Absolute Beginner’s Guide to Building Robots. He is currently working on a best-of collection of his writing, called Borg Like Me.



  1. Mike Mc says:

    Why not rig it up to a water supply so that it will automatically top up the water bowl when it gets below a specified level?

    1. foxops says:

      Thats coming, there will be an automatic safety level at which it will kick in, as well as one to prevent over filling. The overfilling part is important because I plan on inviting the ‘tubes folks to fill the dish for me. Just need to find the right water valve solenoid. Any suggestions?

      1. jes1510 says:

        Look at sprinkler valves. They are relatively cheap and readily available at your local big box home improvement store.

        1. foxops says:

          Yeah I thought about that, most run at a pretty high voltage and I’d prefer something that I can power over USB. I’ve also thought about a low power pump – I actually might be more comfortable with that, for some reason I have a hard time trusting my electronics with the power to flood my apartment :)

  2. karnuvap says:

    Great idea but it seems to be using the Ultrasonic Sensor for the sake of it. With an electronic dipstick you could take a reading of the water level much more easily.

    However I would like to ask if your cat is deaf? Normally cats and dogs can hear ultrasonically and it is the basis of several pet scarers that I have seen advertised.

    Maybe the sampling rate is low and the pulses short enough not to bother it but I’d be worried about the effect of the ultrasonics on the cat.


    1. foxops says:

      True there are easier ways to do it, but since the ultrasonic range finder was the only thing I had on hand that was up to the task – thats what I used, although now that I think of it – I do have a small digital scale, man that would have been so much easier :) As for hurting the cat, I thought of that while wiring it up – when I powered it on I watched her very carefully, she didn’t even turn her head. So either she can’t hear it, or doesn’t care. One advantage over a dipstick is that there is nothing for her to attack or play with, she already splashes around enough in the water as is.

  3. zof says:

    Just a crazy idea, It would be pretty cool to make a robotic arm with the scoop with a web cam attached, then code it into like a flash game and get people online to clean the cat box.

    1. blubrick says:

      Hand control of something like that over to th’ in-tar-webs?
      Not in any house I live in!

      How long would it be before someone found a way of flinging cat crap from pillar to post?

      On second thoughts, you could add a webcam and rename the site “Two URLs – one scoop”.

  4. Reggie says:

    Why bother? Just rig-up a float switch ( ) or make use of cheap optical sensors ( ).