Toilet Tracker: automated poo-spotting, no cameras

It might be that I am unusually particular here, but there is nothing (absolutely NOTHING) that upsets me more than dirty toilets. Yes, I know this is the epitome of a pampered-person’s phobia. But I have nightmares — honest, actual, recurring nightmares — about horrible toilets, and I’ll plan my day around avoiding public toilets which are likely to be dirty. So this project appealed to me enormously.

Obi-Wan and the Worst Toilet in Scotland

Automating spotting that things are awry in a toilet cubicle without breaching privacy is really tricky. You can’t use a camera, for obvious reasons. Over at, Mohammad Khairul Alam has come up with a solution: he uses a Raspberry Pi hooked up to Walabot, a 3D imaging sensor (the same sort of thing you might use to find pipes behind studwork if you’re doing DIY) to detect one thing: whether there are any…objects in the toilet cubicle which weren’t there earlier.

From a privacy point of view, this is perfect. The sensor isn’t a camera, and it doesn’t know exactly what it’s looking at: just that there’s a thing where there shouldn’t be.

The Walabot is programmed to understand when the toilet is occupied by sensing above seat level; it’s also looking closer to the floor when the cubicle is empty, for seat-smudges, full bowls, and nasty stuff on the floor. (Writing this post is making me all shuddery. Like I said, I really, really have a problem with this.) Here’s a nice back-of-an-envelope explanation of the logic:

There’s a simple Android app to accompany the setup so you can roll out your own if you have an office with an upsetting toilet.

Learn (much) more over at Hackster — thanks to Md. Khairul Alam for the build!


Janina Ander avatar

Thanks, Mike! Fixed now.

Rob avatar

You guys must be psychic as I was just thinking whether something like this existed after a particularly bad encounter earlier today. Why can’t people use the flipping toilet brush! It’s the cleaners I feel sorry for, they don’t need that.
Also it might just be me, but Liz, your photo in this context might just be misconstrued ;-)

Liz Upton avatar

Bwa haha

Aaron avatar

Wouldn’t it be nice to be able to connect it to the lock on the stall door so the occupant couldn’t leave unless they’ve flushed and cleaned up after themselves. Not practically doable but just wishful thinking.

Mike avatar

Not sure I agree with the picture, it could easily give kids nightmares about going to the toilet, but in saying that so can opening a toilet door to the wonders of what some people leave behind which is why I think this project is brilliant. The lock concept is also good just a better idea might be to automatically lock the door once the person has left so it cannot be used until clean. The next adult or child would not have to face such an ordeal of having to cleanup the gross mess before being able to use the toilet.

Mark avatar

The Walabot seems kind of expensive, couldn’t most of this be done with an ultrasonic sensor?

Comments are closed