Ah, Halloween. A fun time to hand out candy. Also, a very fun time to scare trick-or-treaters!... But how to combine the two? The Screaming Cauldron allows you to do both at the same time!

By using an infrared distance sensor to determine hand proximity, the Trinket M0 microcontroller adjusts the light colors and then lets out a bloodcurdling, amplified scream at just the right moment!

Build your own -- or any other proximity-based sound/light effects -- using this simple project! You'll have it wired up in no time, and the CircuitPython code is very simple to adjust to suit your needs.

Parts and Materials

You can use any kind of container to house the circuit, I chose an inexpensive plastic cauldron. You may also want some black gaffers tape to hold things down, black tissue paper or fabric to hide the circuit, and some white tissue paper to diffuse the NeoPixels.

Here are the parts for the circuit:

1 x Adafruit Trinket M0
Microcontroller running CircuitPython
1 x IR distance sensor
Proximity and motion sensing in the 10-80cm range
1 x Audio FX Sound Board w 2MB Flash
Triggered .WAV audio files

If you have big plans for lots of sound files, check out the 16mb version. There are also Audio FX Sound Boards with built-in amplifiers in 2mb and 16mb variants, so you have lots of speaker options!

1 x Perma-Proto Half-sized Breadboard PCB
PCB for permanent assembly
1 x NeoPixel RGB LED strip
Black 30 LED strip
1 x 4 x AA Battery Holder w On/Off Switch
To power the project using 4 rechargeable AA batterys

You'll need to supply:

  • 4 AA rechargeable batteries for ~5V of power (Alkaline batteries will be a bit too high, around 6V)
  • Hookup wire
  • soldering iron and solder (if using the perma proto board)

You can use any portable powered speaker you like, or, pick up one of these and a portable USB power supply:

1 x USB powered speakers
With 1/8" stereo audio cable
1 x USB Battery Pack
2200mAh Capacity Battery, 5V 1A Output

If you'd like to watch a full build of this project, check out this John Park's Workshop Live episode:

This guide was first published on Oct 17, 2017. It was last updated on Dec 08, 2023.

This page (Overview) was last updated on Oct 11, 2017.

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