Introduction: Paws to Wash - Cat Meets Covid Handwashing Project

By EPAM Continuum
About: I'm a product designer, an instructor at MIT, author of Enchanted Objects, and part of the amazing team at EPAM Continuum. We have one of the best maker spaces in the world--the MadeReal Lab.

Since we are all distancing at home, Paws to Wash is a DIY project that guides parents and kids through the process of building a cute feedback timer with a waving cat to encourage healthy handwashing habits.

In the time of Covid-19, washing hands thoroughly is essential to keep our families and communities healthy. The research also shows that few of us pause to wash properly every time. Let’s give ourselves a little ambient feedback with light, sound, and cuteness.

This DIY project checks multiple boxes. It:

  • draws attention to the importance of handwashing
  • gives you a fun activity to do with your kids
  • teaches electronics and creative prototyping skills

We offer a list of materials, step-by-step instructions, and code to download for Arduino. Consider this a hardware sketch with lots of opportunities to improvise and personalize. There are many ways to skin this cat: change the countdown lighting and color-patterns, pick your own music or make it a joke machine.

The project is inspired by Maneki-Nike, or the beckoning cat – a Japanese good luck talisman. According to folklore, it sees the future and washes its face just before your guests arrive. The arm action indicates washing –and you should too!

Attachments

Step 1: Order the Components

Step 2: Assemble Circuit Board

Build the Arduino circuit on the breadboard. Follow the wiring drawing on the next page. Leave the battery box disconnected for now. Check your wiring carefully.

Last, load the MicroSD card with a tune

Download the “Jeopardy” tune MP3 from here: http://www.orangefreesounds.com/jeopardy-theme-so...

Plug the MicroSD card into your computer and create a directory called “mp3” Now, write the Jeopardy theme mp3 file into the “mp3” directory you just created on the MicroSD card. Change the name of the file on the SD card from “Jeopardy-theme-song.mp3” to “0001.mp3”
You should now have a directory called “mp3” and a single file within it called “0001.mp3”. This is all required to make the DFPlayer work correctly. Place the MicroSD card into the DFPlayer.

Step 3: Download the Code

Install the Arduino development environment onto your PC or Mac
Download, and set up the Nano with these steps.

Download the following library ZIP files:

Now, open “Paws_to_wash.ino” in your Arduino development environment and click the “check button”. It will probably complain about missing libraries; go ahead and install them from the zip files you just downloaded by following this guide to libraries.

Now, click the check button again. The sketch should compile.

Plug your USB cable into the Nano, and upload the program onto the Nano. You should hear some clicks from the speaker and the Nano’s LEDs will flash. Eventually, you should see the stable LED pattern below, which indicates the Nano is waiting to see a proximity sensor event.

Attachments

Step 4: Build a Base

We found a milk carton, turned inside out was a great waterproof base for our project. Just tape the light ring behind the front face; the LEDs are bright enough to shine through. Make a hole so the proximity sensor can peer out to see your hands as you reach for the soap or faucet. Remember its range is only around 5". We didn't decorate ours, but you could. Write something like "20 seconds for 5,000,000 germs per hand" or "don't forget your thumbs".

Step 5: Install and Wash

Set your animated cat on top, and position it to start when you reach for the soap. Now see if your family is better at washing their hands for a full 20 seconds. Share a picture or video of your project with your friends on social!

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Like most good projects, this was a group effort. Thanks to the team at EPAM Continuum for contributing to this, and the other "Ambient Handwashing Prototypes," which I write about on our blog. Specifically, thanks to Chris Michaud & Jon Campbell for encouraging a DIY version; thanks Bill Gastrock and Peter Simpson for component selection and Arduino wrangling; thanks Tyler Gabriel for the milk carton origami idea; and thanks Nick Steigmann for working on a simpler, more elegant capacitive sensing solution (he has a 3D printer at home which is totally unfair).