I was excited when the Adafruit MONSTER M4SK was announced, because for years I've wanted to make an interactive skull as a Halloween prop - and now there's a project board custom-made to support that!

There are lots of cheesy Halloween decorations out there. That's fine. But I wanted to build something with a bit of subtlety to it, that might attract random Halloween visitors into a memorably creepy interaction rather than just make noise or flash.

This guide is the beginnings of the guts of that project. It modifies the MONSTER M4SK so that its eyes, instead of looking around randomly, track a person in front of them, following their face as it moves.


This design is cheap and cheerful, using an infrared (IR) grid sensor and a simple heuristic to figure out where the human is. There are other approaches using more expensive sensors and processors that might work better.

In particular, this is designed to work outdoors on a cool night. That means the infrared noise floor should be low, and "hot spots" should correspond with uncovered parts of humans, like faces. If you take it into a warm environment, with lots of people around, it may glance around rapidly instead of following the nearest face, and if you put it in front of a bonfire, it may not even notice the humans at all (to be fair, that's how I often react in both of those situations too).

Also, you'll need some way to mount the parts for display - in a creature, mask, pumpkin, skull, scarecrow, or whatever. I plan to share my skull model for 3D printing when it's done, but it's not done yet.

Parts List

The parts needed for this project:

MONSTER M4SK DIY Electronic Face mask.  Two Screens Display Eyes that blink and dart up and down.
Peep dis! Have you always wanted to have another pair of eyes on the back of your head? Or outfit your costume with big beautiful orbs? The MONSTER M4SK
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Video of a hand making bunny ears with their fingers over the AMG8833 IR thermal sensor. A thermal image readout displays on a TFT screen wired into a breadboard.
Add heat-vision to your project with an Adafruit AMG8833 Grid-EYE Breakout! This sensor from Panasonic is an 8x8 array of IR thermal sensors. When connected to your microcontroller (or...
In Stock
Angled shot of STEMMA JST PH 4-Pin to Female Header Cable - 200mm.
This cable will let you turn a JST PH 4-pin cable port into 4 individual wires with high-quality 0.1" female sockets on the end. We're carrying these to match up with any of...
In Stock

Optional Parts

You'll also need something to mount the components in, and a way to power them. Some quick options:

Lithium Ion Polymer Battery 3.7v 2000mAh with JST 2-PH connector
Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This...
In Stock

This guide was first published on Oct 16, 2019. It was last updated on Mar 08, 2024.

This page (Overview) was last updated on Mar 08, 2024.

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