Hello, Halloween Hackfest!

Halloween is possibly the hackiest of holidays. Think about it: when else do you get to add animatronic eyes to everyday objects, or break out the CNC machine to cut into squashes? Labor day? Nope. Proximity-sensing jump-scare devices for Christmas? We think not. But for Halloween, you can let your imagination run wild!

Jump Scare Tombstone by [Mark]
We’re happy to announce that DigiKey and Arduino have teamed up for this year’s Hackaday Halloween Contest. Bring us your best costume, your scariest spook, your insane home decorations, your wildest pumpkin, or your most kid-pleasing feat!

We’ll be rewarding the top three with a $150 gift certificate courtesy of DigiKey, plus some Arduino Halloween treats if you use a product from the Arduino Pro line to make your hair-raising fantasy happen.

We’ve also got five honorable mention categories to inspire you to further feats of fancy.

  • Costume: Halloween is primarily about getting into outrageous costumes and scoring candy. We don’t want to see the candy.
  • Pumpkin: Pumpkin carving could be as simple as taking a knife to a gourd, but that’s not what we’re after. Show us the most insane carving method, or the pumpkin so loaded with electronics that it makes Akihabara look empty in comparison.
  • Kid-Pleaser: Because a costume that makes a kid smile is what Halloween is really all about. But games or elaborate candy dispensers, or anything else that helps the little ones have a good time is fair game here.
  • Hallowed Home: Do people come to your neighborhood just to see your haunted house? Do you spend more on light effects than on licorice? Then show us your masterpiece!
  • Spooky: If your halloween build is simply scary, it belongs here.

Head on over to Hackaday.io for the full details. And get working on your haunts, costumes, and Rube Goldberg treat dispensers today.

Spooky Noise Box Has Post-Halloween Potential

There’s more than one way to scare people on Halloween. Sure, there’s always the low-brow jump scare, but that will generally just annoy the person and possibly cause a heart attack. No, what you need is a sustained soundscape of hellish audio. And where does one find hellish audio? Well, you make your own with a spooky-sounds noise box.

And no, we’re not talking about a soundboard that goes ‘boo’ and ‘ooo-OOO-oooh’ and whatnot. This is a full-on DIY instrument that has potential beyond Halloween. Essentially, the wooden box takes input vibrations from various doodads, and these vibrations are picked up by a piezo disk or two glued to the underside of the lid. The piezos are wired up to a 3.5 mm jack, which runs out to the PC and [SvartalfarQc]’s favorite Digital Audio Workstation (DAW). From there, it’s just a matter of playing around with the sounds — looping them, running them through various instrument voices, adding effects, and so on.

We love the the things that [SvartalfarQc] came up with, including a wind-up walking heart thing, a retractable badge holder, and that noise box mainstay, a sproingy doorstop.

We all know piezos are awesome, but have you ever considered that they can be used to digitize old wax cylinder recordings?

Angry Robot Face Is Less Than Friendly

Sometimes you just need to create a creepy robot head and give it an intimidating personality. [Jens] has done just that, and ably so, with his latest eerie creation.

The robot face is introduced to us with a soundtrack befitting Stranger Things, or maybe Luke Million. The build was inspired by The Doorman, a creepy art piece with animatronic eyes. [Jens’] build started with a 3D model of a 3D mask, with the eyes and mouth modified to have rectangular cutouts for LED displays. The displays are run by a Raspberry Pi Pico, which generates a variety of eye and mouth animations. It uses a camera for face tracking, so the robot’s evil eyes seem to follow the viewer as they move around. In good form, the face has a simple switch—from good to evil, happy to angry. Or, as [Jens] designates the modes: “Fren” and “Not Fren.”

[Jens] does a great job explaining the build, and his acting at the end of the video is absolutely worth a chuckle. Given Halloween is around the corner, why not build five to eight of these, and hide them in your roommate’s bedroom?

Video after the break.
Continue reading “Angry Robot Face Is Less Than Friendly” →

Realistic Animatronic Eyes Are An Easy DIY Build

It’s not Halloween yet, but if you’re planning a technically-complicated costume, it might serve you well to start building now. To that end, here’s a guide from [Ikkalebob] on how to produce a compact animatronic eye mechanism.

The eye is inspired by mechanisms used in professional animatronics. However, that doesn’t mean it’s hard to build. Complex machining is done away with in favor of readily reproducible 3D-printed components. The eyes are able to look in different directions and can move realistically, and the build includes working eyelids that have a great blinking action to them that feels very natural. An Arduino Uno is charged with running the eyes, paired with a bunch of hobby servos and an Adafruit PCA9685 servo driver. A hefty 5V, 4 amp power supply is on hand to deliver enough juice so the servos move smoothly without stuttering.

It’s the kind of thing that’s perfect for your spooky familiar, or installing eyes in the back of your head. It would be perfect to hide behind a window or in the bushes, too. Video after the break.

Continue reading “Realistic Animatronic Eyes Are An Easy DIY Build” →

Build Your Own Mini Fogging Cauldron

The best cauldrons are full of bubbling, steamy potions of great magical potential. We don’t have many of those in the real world, though, so sometimes we have to make do with a simulacra. [wannabemadsci] has built just that, with this fogging cauldron prop that uses no fog fluid or dry ice, running solely with water instead.

The heart of the build is a piezo element that vibrates at ultrasonic frequencies to atomize water. They’re available from websites like AliExpress complete with a driver circuit to energize the piezo element. The water is delivered from a wetted fiber wick, and quickly becomes a fog when the piezo is energized.

The disk was installed in a custom PVC water cup with the wetted wick, along with the electronics. The assembly was then lowered into an off-the-shelf plastic cauldron party favor to complete the look. The trick is to mount the piezo element sideways to get a nice-looking distribution of fog. A green LED was installed to light the cauldron from within.

The resulting effect is a sinister-looking glowing cauldron with a steady stream of fog emanating from the top. It’s a great piece of Halloween decor, and as a bonus, it doesn’t require any fancy chemicals to make it work. If you’re thirsty for more, be sure to check out the winners of last year’s Halloween Hackfest. Video after the break.

Continue reading “Build Your Own Mini Fogging Cauldron” →

A two picture montage of a boy wearing a sonic the hedgehog costume with LEDs in them. The left picture is at night with the boy wearing sunglasses and a face mask with the sonic costume head piece lit up. The right picture is during the day with the boy wearing a face mask, holding a plastic pu mpkin bucket for candy and wearing a lit up sonic the hedgehog costume in the front yard of a house.

LEDs Put New Spin On A Sonic The Hedgehog Costume

[Wentworthm] couldn’t say no to his son’s plea for a Sonic the Hedgehog costume for Halloween but also couldn’t resist sprucing it up with LEDs either. The end result is a surprisingly cool light up Sonic the Hedgehog costume.

a picture of a breadboard with an Arduino Nano on it, with wires going out to 3d printed tear dropped shapes that have LED strips in them, with some LED strips on.

After some experimentation, [Wentworthm] ordered two costumes and ended up mixing and matching the head piece of one with the body suit of the other. For the head, [Wentworthm] created six 3D printed “quills” that had slots for the WS2812B LED strips to slide into and diffuse out the sides, with each quill sliding into the folds of the Sonic head “spikes”. Sewn strips of cloth were used to house the LED strips that were placed down the sides of the costume. An additional 3D printed switch housing was created to allow for a more robust interface to the two push buttons to activate the LEDs. An Arduino Nano, soldered to a protoboard, was used to drive the LED strips with a USB battery pack powering the whole project.

[Wentworthm] goes into more detail about the trials and errors, so the post is definitely worth checking out for more detail on the build. Halloween is always a great source of cool costumes and we’ve featured some great ones before, like a light up crosswalk costume to making a giant Gameboy colour costume.

Video after the break!

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Bike-Riding Skeleton Stalks The Streets On Halloween

Stationary pumpkins and motionless skeletons aren’t enough to scare people these days. If you want to really create a fright on Halloween, you need something more convincing. This bike-riding skeleton from [rc jedi] might just do the trick.

A few neat tricks make this impressive build surprisingly simple in nature. Propulsion is via a scrapped electric scooter drivetrain hidden in the sidecar. This not only propels the rig, but the third wheel means there’s no need to do any fancy balancing work to keep the bike upright. Steering is via a big chunky servo mounted to the bike frame which controls the handlebars. Regular RC gear handles remote control of the steering and drive.

The skeleton itself was an off-the-shelf buy, that was modified to have more flexibility in its joints. The hands were attached to the handlebars, and the feet attached to the pedals, so it appears to pedal the bicycle as it moves down the road. A dog skeleton rides along in the sidecar as a spooky companion.

A skeleton prowling the streets by BMX is a wonderfully spooky sight. We’ve seen some other great skeleton builds before, too, from the canine to the musical variety. Video after the break.

Continue reading “Bike-Riding Skeleton Stalks The Streets On Halloween” →