One of my favorite parts of teaching electronics is seeing what people build once they’ve got a few core skills.

Jason (an Ohmify member) sent over a Halloween project he built with his son: a motion-activated “monster in a box” that pops to life when someone walks by.

Jason described it as “decidedly more low tech” than some microcontroller-heavy builds—but that’s one of the things that makes this a really great project. It’s practical, clever, and built from accessible parts.

Best of all: his 11-year-old loved it, and it became a neighborhood hit.

Check out the details of the built below this video that shows the end result:

The idea: a crate that “wakes up” when you approach

Jason started with a spare shipping crate, gave it a makeover, and turned it into a creature container that:

• Detects motion (like a floodlight would)
• Powers a motor that makes the lid thrash around
• Triggers sound effects through a speaker
• Adds red lighting for atmosphere

The build (high-level)

Here’s Jason’s overview of what went into it:

1) The enclosure

• Spare shipping crate
• Painted for the haunted look
• Hinges added to the top so the lid could move freely

2) The “monster motion” mechanism

The lid movement is driven by a windshield wiper motor—a great choice because it’s designed for torque and continuous movement.

To convert the spinning motion into a creepy lid “chomp/thrash,” Jason made:

• A custom wooden cam mounted to the motor
• The cam pushes/pulls the lid hardware in a repeating cycle, creating that “something is trying to get out” effect

3) Lighting

• Red LED strip inside the crate for an ominous glow

4) Power + motion activation (the simple, effective trick)

Rather than designing a custom controller from scratch, Jason used a classic hack:

• He plugged the motor and LEDs into a power strip
• The power strip plugs into an extension cord
• Then he cut the extension cord and spliced it into a floodlight motion detector

So when the motion detector sees someone nearby, it supplies power—activating the whole “monster” system automatically.

Jason noted that he used soldering skills he learned from Ohmify during the build, which is exactly the kind of real-world win I love hearing about.

5) Sound effects (because the lid alone isn’t enough)

To sell the illusion, Jason added audio:

• A motion-controlled PCB MP3 player module
• Plays a monster sound file through a speaker
• This setup required an external USB amplifier to drive the speaker properly

What’s next: upgrades Jason is already planning

Jason’s already thinking ahead:

• Adding a linear actuator
• Possibly having a skull pop up
• Longer-term: building his own amplifier and MP3 player for more custom control

And in true maker fashion, he’s got other projects in the works too—like building out a BPQ 32 bulletin board system that connects over radio frequencies (no internet).

Halloween just happens to be the perfect excuse to keep building.

Thanks Jason for sharing!

Did you Build Anything?

If you’ve built something with Ohmify—big or small—I’d love to see it. Send a photo and a few notes about what you used and what you learned. Projects like this are proof that a handful of skills (and some curiosity) can turn into something unforgettable.