Hackaday Prize Entry: Arduino Splash Resistant Toilet Foamer

There are some universal human experiences we don’t talk about much, at least not in public. One of them you’ll have in your own house, and such is our reluctance to talk about it, we’ve surrounded it in a fog of euphemisms and slang words. Your toilet, lavatory, john, dunny, khazi, bog, or whatever you call it, is part of your everyday life.

For his Hackaday Prize entry, [VijeMiller] tackles his smallest room head-on. You see, for him, the chief horror of the experience lies with the dreaded splashback. Yes, a bit of projectile power dumping leaves the old rump a little on the damp side. So he’s tackled the problem with some maker ingenuity and installed an Arduino-controlled foam generator that injects a mixture of soap and glycerin to fill the bowl with a splash-damping load of foam. Rearward inundation avoided.

The parts list reveals that the foam is generated by a fish tank aerator, triggered by a relay which is driven by an Arduino Uno through a power transistor. A solenoid valve controls the flow, and a lot of vinyl tubing hooks it all together. There is an HC/06 Bluetooth module with an app to control the device from a phone, though while he’s posted some Arduino code there is no link to the app. There are several pictures, including a cheeky placement of a Jolly Wrencher, and a shot of what we can only surmise is a text, as foam overflows all over the bathroom. And he’s put up the video we’ve placed below the break, for a humorous demonstration of the device in action.

A toilet foamer is new to Hackaday, but we’ve had a few lavatorial projects before. This one with an Arduino saving water, for example, or an auto-flush for a bathroom-trained cat.

42 thoughts on “Hackaday Prize Entry: Arduino Splash Resistant Toilet Foamer

    1. Use a piece of very thin wire e.g. out of a scrap transformer. Nearly invisible and makes it very easy to conceal.

      Something else that can have a similar effect is an ionizer. On a sufficiently dry day, you’ll get charged up by the ions and end up with a static discharge right to the crotch.

      Now what I’m curious about is if females would feel more of a jolt from such a prank. I read that they have roughly twice as many nerve endings in that area as compared to males.

  1. Thx Jenny! Per the missing “app” code — it was such a simple MIT App Inventor build over an image sending any thing other than “0” to trigger the event that it did not dawn on me to include it. I shall resolve that shortly. Per overflow — it times out — after some timing practice. Per “scent” in the video — other users in the household have noticed it actually reduced odor tremendously, even after Chipotle! The rest of what Chipotle does to you, Arduino can’t solve that. — or can it?!

  2. I had an idea like this a few years ago. No electronics, just a few drops from what looks like a mini hand sanitizer dispenser. (You know the brand.) I’m pretty certain somebody sells something similar.
    Some ‘commode styles’ seem to be the worst offenders; most low-flows are designed horribly.

    Would have become an annoying infomercial…

      1. Talking about disgusting.. apparently Americans typically don’t have toilet brushes in hotels / public places? Enjoy the murky poop water created by someone else’s dissolving stains splashing back up at you :’)

    1. I’ve seen “shelved” toilets here and there around the Europe and “normal” ones in Germany. There is a much bigger difference between “Normal” toilets and American ones: the amount of water in the “pool”. In American toilets the pool is quite large and there is a valve at the bottom which opens after. Hence the expression “to flush a toilet”. In “Normal” toilets (shelved or not, it doesn’t matter) the pool is rather small instead of a valve there is a siphon. This is a much better design because there are no moving parts along the way of poop a toilet room is always separated from sewers with the siphon full of water. “Normal” toilets are never flushed. To remove poop water from a tank situated above a toilet is poured which: a) takes poop through the siphon to sewers and b) remains in the siphon. Moreover most tanks today have separate “programmes” (different amount of water) for #1 and #2.

      1. American toilets work on a siphon, there is no valve keeping the water in the bowl. The only “valve” is the flapper in the tank that lifts when you pull the handle, allowing the water to leave the tank to fill the bowl enough to activate the siphone.

  3. With a high fat sausage diet, inspecting for blood in the stool is not unreasonable. Being of a certain age I was recently tasked with getting samples to put on a screening card. (Better than a colonoscopy) The typical American toilet made that a little difficult.

  4. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&sqi=2&ved=0ahUKEwij4cnr99jTAhVU32MKHZxbAtUQyCkIJTAA&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D-XNDM4eAn1U&usg=AFQjCNGJKnL8kJTc2gEd-O8ZYzRrd8QG5w&sig2=3AC0eaK6Qt7bLDTS6OmsYA

    The YouTube channel “Smarter Every Day” did this with a simple sheet of TP on the surface of the water. Someone mentioned this above, but was shot down because “the environment”. However, there is more damage to the environment in the manufacture of an Arduino than in a roll of TP; not to mention the fact that the TP doesn’t require a small, but steady source of power to continue working. The TP trick will work in a blackout.

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