halloween

190 Articles

Skeleton Watches You Intensely Because It’s Halloween, Okay

October 30, 2021 by 1 Comment

If you’ve ever seen a painting in which the eyes follow you around the room, you might have found that a bit uneasy. [CuriousInventor] has taken that concept further with a skeleton that literally holds a gaze on anyone in its field of view. 

The heart of the system is a Raspberry Pi Zero, fitted with a Pi Camera. Running OpenCV, code is set up to track humans and turn the skeleton’s head to face any that are detected. This is achieved via a servo in the skeleton’s neck. A servo bonnet is used to drive the servos without unnecessarily straining the Raspberry Pi.

The skeleton itself doesn’t look modified in any way, though most of the electronics are mounted inside a pretty obvious plastic box. We’d love to see a version 2 with all the hardware housed neatly inside the skull.

It’s a fun hack that makes for an enjoyable Halloween decoration. OpenCV can do other useful things, too, however, like spotting weeds. Video after the break.

Continue reading “Skeleton Watches You Intensely Because It’s Halloween, Okay” →

This Eyeball Watches You Thanks To Kinect Tracking

October 29, 2021 by 4 Comments

Eyeballs are often watching us, but they’re usually embedded in the skull of another human or animal. When they’re staring at you by themselves, they can be altogether more creepy. This Halloween project from [allpartscombined] aims to elicit that exact spooky vibe.

The project relies on a Kinect V2 to do body tracking. It feeds data to a Unity app that figures out how to aim the eyeball at any humans detected in the scene. The app sends angle data to an Arduino over serial, with the microcontroller generating the necessary signals to command servos which move the eyeball.

With tilt and pan servos fitted and the precision tracking from the Kinect data, the eye can be aimed at people  in two dimensions. It’s significantly spookier than simply panning the eye back and forth.

The build was actually created by modifying an earlier project to create an airsoft turret, something we’ve seen a few times around these parts. Fundamentally, the tracking part is the same, just in this case, the eye doesn’t shoot at people… yet! Video after the break.

Continue reading “This Eyeball Watches You Thanks To Kinect Tracking” →

ESP32-Cam Makes A Dandy Motion Detector

October 23, 2021 by 7 Comments

Halloween is right around the corner and just about every Halloween project needs some kind of motion sensor. Historically, we’ve used IR and ultrasonic sensors but [Makers Mashup] decided to use an ESP32-Cam as a motion sensor in his latest animatronic creation. You can see a video of the device and how it works below.

The project is a skull that follows you around with a few degrees of motion on a stepper motor. There’s a 3D-printed enclosure to make the hardware assembly easy. The base software was borrowed from [Eloquent Arduino].

Continue reading “ESP32-Cam Makes A Dandy Motion Detector” →

Flickering Jack O’ Lantern Is An Easy Beginner Build

October 19, 2021 by 8 Comments

The Jack o’ Lantern is a fun Halloween tradition, though one that does come with a few risks. It’s pretty easy to slice off a bit of finger when carving a stiff pumpkin, and candles draw more enmity from fire crews than most household items. For the electronics beginner looking for a learning project, [Oyvind’s] build might be a nice safe bet.

The build starts with a 3D-printed pumpkin figurine with a suitably spooky face, though [Oyvind] notes there’s nothing stopping this project from being executed with a real orange gourd instead. Inside, an Arduino is hooked up to a trio of orange LEDs. They’re attached to PWM pins and each is given a random brightness value at regular intervals to create a pleasant flickering effect.

It’s a very simple project, but it’s also the kind of thing that’s perfect for introducing new people into the world of electronics. There’s little to get wrong, and mistakes aren’t costly, making it an ideal project for beginners. From there, the sky really is the limit! Video after the break.

Continue reading “Flickering Jack O’ Lantern Is An Easy Beginner Build” →

Ultrasonic spirit writing

Ultrasonic Array Powers This Halloween Spirit Writer

October 12, 2021 by 16 Comments

The spooky season is upon us, and with it the race to come up with the geekiest way to scare the kids. Motion-activated jump-scare setups are always a crowd-pleaser, but kind of a cheap thrill in our opinion. So if you’re looking for something different for your Halloween scare-floor, you might consider “spirit writing” with ultrasound.

The idea that [Dan Beaven] has here is a variation on the ultrasonic levitation projects we’ve seen so many of over the last couple of years. While watching bits of styrofoam suspended in midair by the standing waves generated by carefully phased arrays of ultrasonic transducers is cool, [Dan] looks set to take the concept to the next level. Very much still a prototype, the setup has a 256-transducer matrix suspended above a dark surface. Baking powder is sprinkled over the writing surface to stand in for dust, which is easily disturbed by the sound waves reflecting off the hard surface. The array can be controlled to make it look like an unseen hand is tracing out a design in the dust, and the effect is pretty convincing. We’d have chosen “REDRUM” rather than a pentagram, but different strokes.

[Dan] obviously has a long way to go before this is ready for the big night, but the proof-of-concept is sound. While we wait for the finished product, we’ll just file this away as a technique that might have other applications. SMD components are pretty small and light, after all — perhaps an ultrasonic pick-and-place? In which case, sonic tweezers might be just the thing.

Continue reading “Ultrasonic Array Powers This Halloween Spirit Writer” →

Fire-breathing dragon head, side view

Flame-Spitting Dragon Head Heats Up Halloween

October 4, 2021 by 4 Comments

Halloween is looming, and [Jonathan Gleich] decided that an ideal centerpiece would be a flame-spitting dragon’s head. It started with an economical wall-mount dragon’s head, combined with a variety of off-the-shelf components to become something greater.

Dragon head with arc ignitor lit
Spark from high-voltage ignitor, right at the torch opening.

The fire comes from a kind of propane torch sold as a weed killer set, which looks a little like a miniature tiger torch. The flow of propane is limited by a regulator (which keeps the flame short and fixed), and controlled with a gas-rated 12 V solenoid valve. Ignition is done with the help of a spark igniter that fires up on demand, fed by a high-voltage ignition coil. The two combine at the Dragon’s mouth, where the flame originates, but the electrical components are otherwise isolated from the gas elements as much as possible.

The dragon head is made of acrylic, and if exposed to enough heat acrylic will first melt, then burn. To help avoid a meltdown, the dragon breathes fire only intermittently.  [Jonathan] also gave the mouth area a heat-resistant barrier made from generous layers of flame-blocking mortar and sealants from the hardware store. The finishing touch comes in the form of bright red LEDs in the eyes, which give the head a bit more life.

Watch the ignitor in action and see the head spewing flames in the two short videos embedded below. The head should make for some good pictures come Halloween, and is a good example of how repurposing off-the-shelf items can sometimes be just what is needed for a project.

Interested in something smaller, but still fiery? Check out this pet fire-breathing dragon project for all your robotic animal companion needs. Continue reading “Flame-Spitting Dragon Head Heats Up Halloween” →

Get Yer Halloween On!

October 2, 2021 by 3 Comments

Halloween is basically built for the hacker. Besides the obvious fabrication of absurd costumes, there’s also the chance to showcase your skills, be they mechanical, audio, or video. It’s also a great time to show off our coolest tricks to inspire the young proto-hackers. If you need inspiration, we’ve got 150 ideas.

[Brankly]’s Candy Dispenser
My personal problem with Halloween, though, is that I always start at the last minute, and my ideas far outreach my time budget. Or because it’s all done in the last minute, a whole bunch of ideas that should “just work” in theory run into the immovable object that is practice. At least that’s what happened with last year’s spooky sound effects — my son and I spent so much time collecting and recording scary audio samples that I ran out of time while still getting the sensitivity on the motion detector set just right, and then the battery died halfway through the night.

But this year will be different, I swear! I’m going to get it done early and test it out, with the luxury of time to debug the inevitable spiders. And you can swear too. Get started now on your Halloween project. Or at least next weekend.

What’s your favorite Halloween Hack?

Contests

If you need any more encouragement to fire up your black and orange hacking machine, think of Hackaday.io’s Halloween Hackfest. It runs until Oct 28, and all you have to do to enter is document your Halloween project on IO and press the “Submit” button. The deadline is the 28th, which still gives you a couple of nights to debug whatever didn’t work before the real deal. Prizes are shopping sprees at Digi-Key, and Adafruit is doubling the gift certificate if you use any Adafruit parts in the build.

If you don’t give a pumpkin about stupid ol’ Halloween, that’s cool too. (Grinch!) The 2021 Hackaday Prize has entered the final wildcard round. If your project didn’t fit in any of the previous categories, I’m pretty sure it’ll fit just fine in the anything-goes phase. Go nuts. We’d love to see what you’re working on.

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