We've all been there before. Your hands are soaking wet because you're decent enough to wash them but you really don't want to undo all of your hard work and touch the same towel dispenser that everyone else has. Sure, you could be lucky enough to find yourself in front of one of those motion sensor ones that require you to wave your hands like a maniac just to get a paper towel — but if you're luckier, you can use this cool voice-activated Raspberry Pi paper towel dispenser put together by maker and developer 3megabytesofhotram and yell your paper towel into existence.
Before we get too deep in to the story (its not April 1st yet), yes, we are well aware that the source of this project is a prank. We've seen stickers for "voice activated printers / photocopiers and even a lift" but until now, they were just pranks. With the power of a Raspberry Pi 4 we can now make these pranks a reality.
This voice-activated paper towel dispenser works just as you might imagine. When you want it to dispense part of the roll, say the trigger word aloud (in this case, "dispense towel") and wait for your paper towel to unfurl. This project wasn't made entirely from the ground up but rather uses a modified manual paper towel dispenser.
Maker 3megabytesofhotram started with a Scott brand paper towel dispenser and from there, incorporated our favorite SBC to make the system automated. The Pi is fitted with a microphone to listen for the trigger word. Once activated, it drives a servo motor that rotates the internal pulley which makes the paper towel dispense.
If you want to recreate this project, it would help to use the exact paper towel dispenser model that 3megabytesofhotram is using as the 3D printed components were designed to accommodate it specifically. Maker 3megabytesofhotram confirmed that he's using a Scott Pro Manual Hard Roll Towel Dispenser. Driving the operation is a Raspberry Pi 4 with 2GB of RAM connected to an L298N 1A DC motor driver, a 12V DC Motor and a microphone.
As with many open source projects, you can find source files over at the official project page. While we don't get a good look at the code, the 3D printer STL files have been made available that can be used to mount the hardware inside. There's also a video demo of the project in action over at Vimeo.
If you want to get a closer look at this Raspberry Pi project, visit the project page shared to Hackaday where you'll find more details and tons of pictures showing off the inside.
