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.
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 Hackster.io, 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!