Tired of queuing for the office toilet? Meet Occu-Pi

This is the story of Occu-Pi, or how a magnet, a Raspberry Pi, and a barrel bolt saved an office team from queuing for the toilet.

Occu Pi Raspberry Pi toilet signal

The toil of toilet queuing

When Brian W. Wolter’s employer moved premises, the staff’s main concern as the dearth of toilets at the new office, and the increased queuing time this would lead to:

Our previous office had long been plagued by unreasonably long bathroom lines. At several high-demand periods throughout the day we’d be forced to wait three, four, five people deep while complaining bitterly to each other until our turn to use the facilities arrived. With even fewer bathrooms in our new office, concern about timely access was naturally high.

Faced with this problem, the in-house engineers decided to find a technological solution.


The main thing the engineers had to figure out was just how to determine the difference between a closed door and an occupied stall. Brian explains in his write-up:

There is one notable wrinkle: it’s not enough to know the door is closed, you need to know if the bathroom is actually in use — that is, locked from the inside. After considering and discarding a variety of ‘creative’ solutions (no thank you, motion sensors and facial recognition), we landed on a straightforward and reliable approach.

The team ended up using a magnet attached to the door’s barrel bolt to trigger a notification. Simply shutting the door doesn’t act as a trigger — the bolt needs to lock the door to set off a magnetic switch. That switch then triggers both LED notifications and updates to a dedicated Slack channel.

Occu-Pi Raspberry Pi toilet signal

For the technically-minded, Occu-Pi is a pretty straightforward build. And those wanting to learn more about it can find a full write-up in Brian’s Medium post.

We’ve seen a few different toilet notification projects over the years, for example this project from DIY Tryin’ using a similar trigger plus a website. What’s nice about Occu-Pi, however, is the simplicity of its design and the subtle use of Slack — Pi Tower’s favoured platform for office shenanigans.


Norman Dunbar avatar

Raspberry Pee? (As I believe the French call the Pi!)


Ryan Corneliusen avatar

Went not just use the light switch as the trigger? Or do you guys have a motion detection light?

Alex Bate avatar

That would involve training staff to turn the light off when they leave.

Bob avatar

And some folks appreciate the last user leaving the light (and therefore fan) on when the exit…depending on whether or not there is residual air pollution…

Tzarls avatar

I see the need to add an air quality sensor to this build … hmmmmmm….

Niels avatar

Brilliant names, great invention

Pete avatar

And once again: REALLY? A full grown up somewhat supercomputer to control some LEDs? REALLY? Do you use a 747 to buy some food? Or some kind of sword to cut your vegetables?!

AndrewS avatar

I guess you must have missed the “… and updates to a dedicated Slack channel.” part?

Rowan avatar

Why not scrape the slack channel for entries and analyse your colleagues bowel movements? Nominally you can search for warning signs of disease or IBS, in reality you can identify the slackers.

chris avatar

I was confused becouse this is an occu https://github.com/eq-3/occu (since many years) .they should search for an other name

Jose avatar

Now all they have to do is to add a queue manager so people can book “loo” slots, and may be even sell them if someone really needs to go and you got it booked :-)

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