Is the toilet free?

Here at Pi Towers, we are lucky enough to have more toilets than we have people. Some offices don’t. And it’s embarrassing to hear your colleagues micturating (at least for some people – the rest of us chatter through it all and make fun of each other’s shy bladders), so the guys at Made by Many have come up with a Pi-based solution.

It started quite simply. Reed switches on a toilet door would send information to a Pi, which would publish the data to a website, so the folks at Made by Many could check online before going to the loo. They made a LEGO prototype to make sure everything worked.


And after applying the switches to the real toilet doors, they ended up with the real thing serving up a result like this when the website was polled.


Of course, it’s axiomatic that if you can overcomplicate something, you should.

So the Made by Many team started looking at what data they could collect without invading people’s lavatorial privacy (with a privacy document being uploaded to GitHub). No identifying information or information about exactly what was going on in the cubicle was collected at any time.  Over three weeks they ended up with sufficient data points to work some SQL magic and be able to detect:

  • if the toilets are free
  • the total number of visits
  • minimum visit duration
  • maximum visit duration
  • average visit duration
  • total visits by hour
  • total visits by day

From which they could infer:

  • the office’s favourite toilet
  • peak times
  • off-peak times
  • an estimated wait time.

And then they made a command-line-style stats page.


And because a job half-done is no job at all, they also made a little toilet notifier to live in the menu bar in Mac OS.


They’ve made LED signs. They’ve irritated their colleagues so much that one of them dismantled and abducted one of the reed switches. They’ve demonstrated elegantly that the Internet of Things is always informative, and not always as useful as we think it is. We think this is one of the most entertaining projects we’ve seen in a while. We salute you, Made by Many. And if you’ll excuse me, I drank rather too much coffee after lunch. I’ll just be a minute.


Michael Horne avatar

Brilliant. Simply brilliant. So much work involved for something so silly, and yet sort-of useful at the same time :-)

Russell Barnes avatar

We urgently need this!

John avatar

Wow, this would seriousl improve productivity!

Peter Ryan avatar

I’ll just be a minute
And now we can check too! :O

If it were integrated with your calendar, and referenced where you’d eaten the night before, it could maybe offer a prediction as to how long you’d be.

And why stop there? That data could by syndicated to betting companies, so that super rich oligarchs could bet on just how long people take in the lav.! It could create a whole new industry!!!!

+1 for being slightly less creepy than the “toilet-monitor” featured here ages ago that used a camera (from memory) to, er… notice changes in lighting. Or something. It was weird!

Phil Spencer avatar

Excessive…..yet impressive

Dave avatar

I implemented this for our office a while ago – in fact, I heard my boss whistling a moment ago & glanced up to see that the men’s room is occupied :-)

I built a pair of red/green icons (men’s & women’s restroom) into the dashboard application that everyone in the office uses plus a little python status icon application for the Ubuntu desktop that I use. It’s been a great help to people working in our warehouse, who previously had to walk to the front of the office to see if the restroom is occupied.

For privacy reasons the application does not log any door openings/closings, so I can’t provide any stats.

Davespice avatar

I love it :)

Lee Jones avatar

A lack of tp or bog roll emergency switch might be useful too. Not my idea, I stole it from James May’s man lab. Lego and Rpi are a perfect complement to each other. My Rpi case is built from lego.

Liz Upton avatar

Now *there’s* an idea for an educational resource.

David avatar

Don’t know what the fuss is about really – isn’t this a bog standard application for the Pi?

ukscone avatar

>with a privacy document being uploaded to GitHub

should that be

with a privy document document being uploaded to GitHub ?

Hogginda Poti avatar

just so you know, the URL in the first picture is missing a colon. how appropriate!

Tim Rowledge avatar

This needs integrating with the coffee pot (and teapot!) camera system. Some image analysis along with careful time & volume logging should enable *predictive* wait-time & busy time presentation.

Dougie avatar

If your office does have enough facilities, then that’s in contravention of the 1963 Offices, Shops & Retail Premises Act (as amended) and you should contact the local council. It’s not a problem to be bypassed with funky programming and a few sensors/switches on a Raspberry Pi.

We need to take action on these infringements of the OSRP.

Adam avatar

I have no idea whether you’re trolling, but places often have toilet ‘surges’ after company meetings, talks, lunch, etc. Accommodating so that everyone can always have a toilet in these rare peaks is wholly unnecessary

Haggishunter avatar

This reminds me of a toilet in the biology department of a well-known university in the Southwest. Scratched into the door of the end cubicle was the legend, “Smile! You are live on“.

I don’t think I ever checked the URL.

Pick Up a Pi avatar

I look forward to the ‘toilet of the month’ becoming commonplace in companies across the world!

Ogoshi avatar

Perhaps an odor sensor would be a useful addition… Just because the loo is available, doesn’t mean you should use it just yet!

Monkeymademe avatar

I would really like to know how the macos menu bar thingy

John avatar

Vanderbilt University did something similar to this years ago where they studied bathroom usage… And you thought the MIT Coke machine in the LCS/AI building was cool…. Its the early examples of the IoT

Simon Walters avatar

I’m SO going to do a project like this in my schools – brilliant idea :)

Ken Harbit avatar

You have way to much time on tour hands … :)

Bill Stephenson avatar

That is cool stuff. Great work!!

I swear I haven’t read others comments yet, but that is certainly a person juggling balls (or something)…

Bill Stephenson avatar

Yikes. I think I commented on the wrong post. Still getting used to the new site I guess.


AndrewS avatar

This should be nicknamed the Pee Pi :-)

nathanael avatar

Why not just use the camera module?

Giuseppe Bertucci avatar

few reasons…
privacy (you don’t be recorded when leave the toilet),
ability to integrate with other systems (e.g. sms send when the toilet is available), usage monitoring (how long is the average use of a toilet)

just few ideas in 10 seconds of thinking, but in general is always better to have “raw data” instead of images/video

Helen Lynn avatar

A commenter on our Google+ page describes doing something analogous a long time ago – people would dial a particular phone extension and hear a high-pitched tone if any of the loos were free and a low-pitched one if not.

Scott Prive avatar

Yeah I think the first known case of this is from MIT. Their loo website’s no longer up or at least accessible from the Internet, but the Slashdot commentary is available here:

This would also be good for remotely knowing which showers are available (so long as each door is solid and lockable, just tie into the lock. Won’t work with curtains obviously.)

Scott Prive avatar

I forgot to add: well done! :-)

Stuart Tetley avatar

Brilliant! And educational. For 35 years, I assumed ‘micturations’ was a made-up Vogon word. I now know better!

David avatar

Does anyone know if the SQL database was stored on the Pi or was the Pi just used to collect the data?

What a great idea! The Raspberry Poo.

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