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:

Adafruit MONSTER M4SK - DIY Electronic Eyes Mask

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

Adafruit AMG8833 IR Thermal Camera Breakout

Add heat-vision to your project and with an Adafruit AMG8833 Grid-EYE Breakout! This sensor from Panasonic is an 8x8 array of IR thermal sensors. When connected to your microcontroller...

JST PH 4-Pin to Female Socket Cable - I2C STEMMA 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...

Optional Parts

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

Lithium Ion Battery - 3.7v 2000mAh

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 battery...

Hobby Creek Mag Hand Professional Workstation

Just when we begin to think that Hobby Creek couldn't possibly offer another third hand product that would raise the bar of awesome-ness, they go ahead and do it! The...
This guide was first published on Oct 16, 2019. It was last updated on Oct 16, 2019.
This page (Overview) was last updated on May 31, 2020.