Community Project - hand washing reminder (suggestions wanted)

With the corona virus in the news everywhere, my daughter asked me to come up with a way to remind her kids - and anyone else who comes in the house - to go wash their hands.

I was thinking of a Pi with a camera and some code to determine if it is a person coming in (and not the family dog jumping at the door) and then send a message to Alexa (or anyother smart speaker) to broadcast a reminder to wash your hands.

As a bonus, maybe add a button in the bathroom that you would have to push to shut Alexa up and maybe trigger a count down timer so if you don't wash your hands within a certian amount of time, engage an alarm.

Some of the challenges I can think of are:

  • determine if someone is coming in the door or going out
  • ignoring people walking around and just passing by the door
  • ignore animals (dogs and cats)
  • making it modular -
    • for different smart speakers or a speaker connected to the Pi,
    • for a pi camera vrs usb camera vrs espcamera
    • Minimum hardware to run it on
    • What nodes should be used, are there nodes that will work with a usb camera, pi camera

Any ideas, suggestions even code is welcome. This is something I thing a lot of people could benefit from so thanks for anyones ideas.

1 Like

You could also...
Connect a thermal imaging camera to the Pi so it can take your temperature and only if it is normal will it let you in.
If the temperature is HIGH then send a message via Telegram to the local medical centre.


A related and possibly useful thread from twitter


And then clean the button after washing your hands


Indeed, my suggestion is: "no buttons"!!!

Voice activated only please :slight_smile:

You should also add a sound sensor for the bathroom to make sure that people wash their hands for the required 20-30sec minimum. Or you can go for maximum annoyance and play Happy Birthday twice through. :crazy_face:


Hmm, any suggestions for a suitable camera? Would make an interesting project for when I'm self isolating!

Though in truth, I now mainly work from home so I'll doubtless have to keep working no matter how sick I get :frowning: Hoping that I won't get sick of course, especially now that I've flipped over into the higher-risk age bracket!

Well, all of this is making me super conscious of touching my face!!

There are low res ir chips available if you can’t effort a flir
AMG8833 IR 8*8 or MLX90640 32x24

1 Like

Don't know if they're sensitive enough for actual body temperature, but Adafruit AMG8833 perhaps, or Pimoroni's PIM365, which comes with a Melexis MLX90640 far-infrared sensor array.

You could use a normal camera, and do object detection on the images. I see that our friend @dceejay offers the node-red-contrib-tfjs-coco-ssd node, which is based on Tensorflow.js. The coco-ssd model has been trained to detect 29 different kind of objects, and in their code you can see that it can detect persons...

But I have not been able yet to try it myself!

1 Like

...this project is a scheme to trick ourselves into quarantine...with our heads busy, we simply forget that the outside world exists :rofl: :upside_down_face:


I tried some of the others from the Twitter link he shared. All ran in the browser but none worked especially well. They got confused by wearing a headset with boom mic or were really slow to react.

With an IR camera, I'd set one up next to a mirror so that people could easily position themselves.

Might try one of my waterproof thermal sensors though to see if they are reactive/accurate enough on skin. Easily cleaned & simple to use/set up.

Expensive and not very good!

Not looking hopeful there. Probably better to stick with a simple DS18B20 to measure contact temperature and provide suitable wipes to clean it.

DS18B20 I like it!! I have a number of waterproof ones!


here's an option too:

Hahaha do you know how long that bottle would last with a 7 and 5 boys near by? I'm guessing half hour at the longest. :rofl:

Actually I'm writing up what I've done. I'm using a camera to take a picture and then the node-red-contrib-tfjs-coco-ssd to identify if it contains a person. Then a msg is sent to the playsound node to play a wav file saying "Please go wash your hands...right now!"

I've got a HiHiBerry miniamp on a small speaker. Next I have to package the whole thing...if the grandkids ever give me a chance :grin:

The only problem I would have here in the UK in implementing this project is...
finding the handwashing gel as ALL the shelves in ALL the supermarkets are bare!!!

Also toilet rolls and Paracetamol tablets are non-existent here, we are all going to die!!!

DynamicDave AKA DramaticDave (thanks Steve).

I think it's time to change your name to DramaticDave haha


Oooohhh - I really like that title, I might adopt it.

Get a supermarket delivery a few days out, they tend to have things in stock. Paracetamol is available but you have to pick a local Pharmacy rather than the big supermarkets, or find out when they get their next delivery. Lemsip is also still on the shelves, the crazy panic-buyers don't seem to have enough braincells to realise that is the same stuff.

If you have any isopropanol alcohol (e.g. for cleaning electronics), you can easily make your own gel. Just make sure the result is 60-90% alcohol. But of course, soap is better if you are near it and water :grinning:

1 Like

I thought you was just an expert on computer viruses :rofl: :rofl: :rofl: