Spooky Winners Of The Halloween Hackfest Contest

November 4, 2021 by Kristina Panos No comments

It was a tight race, but the results of the Halloween Hackfest contest are in. We asked you to scare up a terrifying build in one of three categories, and as usual, you didn’t disappoint! These three hackers have each won a $150 shopping spree at Digi-Key to fund their future frights.

Best Undead Tech: 3-Axis Skull Mod for a 12-Foot Skeleton

Nelson Bairos

[Nelson] has been in the Halloween-based animatronics business for more than a decade, but always gets beaten to the punch when it comes to doing the really fun stuff like making things move and speak. Once [Nelson] got their hands on a 12-foot skeleton from the big box hardware store, it was time for the gloves to come off and the fun to begin.

The three axes of movement come from a rotation servo, a tilt servo, and a nod servo, all of which are connected to each other and the skeleton with 3D-printed supports. Lucky for us, [Nelson] documented this first build quite nicely and provided the 3D models, should you suddenly get the urge to go see if they have any of these magnificent skeletons left on clearance.

Best Haunted Smart House: Safety Coffin Grave Bell

Glen Atkins

What’s scarier than the undead? How about people who were buried alive, whether accidentally or not. Can you imagine hanging around in a graveyard, innocently doing tombstone rubbings or some ritualistic sacrifice when suddenly you hear someone ringing a bell and/or a terrified, muddled voice screaming for help?

[Glen Atkins]’ Safety Coffin Grave Bell build forgoes the body part, but in the dark, it’s easy to let your imagination run wild. It looks like a bell on a post, but pass too close and the ultrasonic rangefinder detects unsuspecting trick-or-treaters and gives them a scare by frantically ringing the bell with a big servo hidden inside. We hope they brought spare underwear.

Best Crazy Costume: Computer Head

Skye Rutan-bedard

[Skye] won a lot of people over last year with their computer head costume that featured a lone blinking eye and a voice. What those people didn’t know was that it suffered from three big problems: it had poor ergonomics from a heavy monitor shell, the blinkenlights matrix used to display emotions was underutilized, and using a keyboard proved to be an inconvenient UI for running the voice. This year, [Skye] set out to fix all the problems and make the costume even more awesome and comfortable to wear.

The brain of this computer head costume is a Raspberry Pi 4. As for [Skye]’s actual head, it is safely enclosed inside a hard hat that’s epoxied to the inside of the case. A wide range of emotions dance across the 16×16 RGB LED matrix that looks great behind some mirrored film, and they go great with the new voice method — [Skye] speaks softly into a small microphone, and the Raspi uses Mozilla’s DeepSpeech to repeat whatever they say in a robotic British accent.

Hack-y Halloween

Congratulations to all the winners, and a big thank you to all 45 entrants for your hair-raising hacks. Thank you also to Adafruit and Digi-Key for sponsoring this contest. We hope you had a great Halloween!

Skeleton Watches You Intensely Because It’s Halloween, Okay

October 30, 2021 by Lewin Day 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.

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This Eyeball Watches You Thanks To Kinect Tracking

October 29, 2021 by Lewin Day 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.

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ESP32-Cam Makes A Dandy Motion Detector

October 23, 2021 by Al Williams 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].

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Flickering Jack O’ Lantern Is An Easy Beginner Build

October 19, 2021 by Lewin Day 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.

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Ultrasonic Array Powers This Halloween Spirit Writer

October 12, 2021 by Dan Maloney 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.

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Flame-Spitting Dragon Head Heats Up Halloween

October 4, 2021 by Donald Papp 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” →