Ask Hackaday: Wiping Your Bum With An Arduino?


Over or under? Standing or sitting? Truly, toilet paper has been the focus of the most irreconcilable arguments ever. The folks on the Arduino Stack Exchange have a far more important question: how do you trigger an alarm when your TP supply is low?

[user706837] asked the Internet this question in response to his kids never replacing an empty roll. This eliminates the most obvious means of notifying someone of an empty roll – looking at it before you sit down – and brings up a few interesting engineering challenges.

Most of the initial ideas deal with weight or some sort of light sensor that can differentiate between the white TP and the brown roll. A much, much more interesting solution puts a radioactive source in the TP holder’s spring-loaded rod and uses a sensor to detect how much TP is left. A quick back-of-the-wolfram calculation suggests this might be possible, and amazingly, not too dangerous.

We’re turning this one over to you, Hackaday readers. How would you design an empty toilet paper alarm? Bonus points awarded for ingenuity and cat resistance.

Image source, and also one of the longest and most absurd Wikipedia articles ever.

Hackaday links: April 10, 2011

Sunlit LCD screen

[A.J.] did some experiments and managed to replace his LCD backlight using fiber optics and the sun.

Game Boy LCD Repair

[Alan] found that he could fix dead columns on his Game Boy LCD screen with a little reflow work on the connector.

3DS Design Flaw?

Anyone having problems with the way their Nintendo 3DS closes? [Jeroen] noticed that his screen touches the other half of the device when closed. He added rubber feet to protect it, but we wonder if anyone else has noticed this issue?

Mac TP dispenser

This one takes iLife to a new level. Never poop without Apple’s consent again thanks to this Macintosh toilet paper dispenser. [Thanks Rob]

Children are the future

Here’s a heart warming way to end; [Bret] is teaching his 5-year-old son to solder. There’s a video that is sure to put a smile on your face. You’ll remember [Bret] (aka [FightCube]) from the adjustable prank box, a few 555 timer contest submissions, and several other hacks. We expect big things from your progeny!

Toilet paper dispenser

Solving the age old problem of… wait, what problem are they solving? These students at UC Berkeley have built a toilet paper dispenser prototype. Not only does it meter out an exact amount for you, it will fold it and cut it as well. They mention this being the perfect accessory for a high tech bathroom, and we can agree. To be serious though, in public places, metering out limited amounts of toilet paper at a time could possibly result in major cost savings. We think the next prototype should have different preference settings such as; wadded, folded, or wrapped around your hand. Anyone else’s mind suddenly filled with unpleasant imagery?

[via Makezine]