DIY Scream Canister Pays Homage to Monsters, Inc.

In case you missed it (shame on you), Monsters, Inc. is a 2001 animated movie from Pixar. We won't go into the details of the plot, but the story hinges on the existence of monsters. Those monsters power their technology using kids’ screams, which the monsters collect using scream canisters after frightening the children in amusing ways. Erv Plecter, proprietor of Plecter Labs, built his own real life scream canister replica that acts like a portable voice recorder.

Plecter took on this project after his friend Chris started modeling a scream canister to practice his Autodesk Fusion 360 CAD modeling skills. Chris only planned to create a "dummy" replica, but Plecter has a lot of experience building replica props with electronic components and decided to one-up his friend by building a functional scream canister. It can record audio and the play back the recording. It even has an illuminated bar graph to indicate the capacity of the canister, just like in the movie.

Instead of creating the 3D model from scratch as Chris was doing, Plecter started with an existing model created by Microwavabletofoo and uploaded to Thingiverse. Plecter 3D-printed the replica canister in several pieces using yellow and black PLA, ABS, and translucent Zortrax Z-GLASS filament for the capacity gauge window. Behind that window is a mini bar graph made of WS2812B individually addressable RGB LEDs on an OSH Park protoboard.

That LED board connects to the brain of the project: a Crystal Focus Soundboard (CFX). The CFXboard is meant for adding sound effects to DIY lightsaber builds, which is Plecter's area of expertise. It has an onboard 12-bit ADC (analog-to-digital converter), which let Plecter sample audio at 22.050kHz and store it on an SD card. Audio comes in through a microphone and MCP6231 op-amp. A small button on top lets the user start recording with a short press or trigger playback with a long press. While it is capable of recording longer clips, Plecter setup the bar graph to sync with 10 second clips.

While this is a novelty, it will certainly appeal to Pixar-loving couples who want to leave each other short voice messages. It would also make a great toy for kids who love Monsters, Inc.