Halloween Doorbell Prop in Rube-Goldberg Overdrive

[Conor] wired up his 3D-printed coffin doorbell to an array of RGB LEDs, a screaming speaker, and a spinning skull on a cordless screw driver to make a “quick” Halloween scare. Along the way, he included half of the Adafruit module catalog, a relay circuit board, and ESP8266 WiFi module, a Banana Pi, and more Arduinos of varying shapes and sizes than you could shake a stick at.

Our head spins, not unlike [Conor]’s screaming skull, just reading through this Rube Goldbergy arrangement. (We’re sure that’s half the fun for the builder!) Smoke ’em if ya got ’em!

Start with the RGB LEDs; rather than control them directly, [Conor] connected them to a WiFi-enabled strip controller. Great, now he can control the strip over the airwaves. But the control protocol was closed, so he spent a week learning Wireshark to sniff the network data, and then wrote a Bash script to send the relevant UDP packets to turn on the lights. But that was not fancy-schmancy enough, so [Conor] re-wrote the script in Go.

Yes, that’s right — a Go routine on a Banana Pi sends out custom UDP packets over WiFi to a WiFi-to-LED-driver bridge. To make lights blink. Wait until you see the skull.

spooky_eye_animThe plastic skull has Neopixels in each ping-pong ball eye, controlled by an Arduino Nano and battery taped to the skull’s head. The skull is cemented to a driver bit that’s chucked in a cordless drill. A relay board and another Arduino make it trigger for 10 seconds at a time when the doorbell rings. Finally (wait for it!) an Arduino connected to the doorbell gives the signal, and sets a wire high that all the other Arduini and the Banana Pi are connected to.

Gentle Hackaday reader, now is not the time for “I could do that with a 555 and some chewing gum.” Now is the time to revel in the sheer hackery of it all. Because Halloween’s over, and we’re sure that [Conor] has unplugged all of the breadboards and Arduini and put them to use in his next project. And now he knows a thing or two about sniffing UDP packets.

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Hacklet 82 – Halloween Hacks 2015

Halloween is when the ghouls start haunting and the hackers start hacking. All hallows eve is the perfect holiday for eerie blinking LEDs, spooky audio oscillators, and wild animatronics. We had a double dose of Halloween hacks last year on the Hacklet. This year we’re bringing you even more of the best Halloween hacks on hackaday.io!

eyes1We start with [dougal] and Halloween Blinky Eyes. [Dougal] wanted to create the effect of creatures peeking at you from the dark corners of the room, and he’s certainly nailed it. A strip of WS2812 LEDs is the trick here. Pairs of LEDs light up, blink, and fade away like spooky eyes. The Strip is controlled by a Particle Core using Adafruit’s NeoPixel Library, though [Dougal] plans to move to the FastLed library. Everything is powered by a USB power pack. This hack isn’t much to look at with the lights on, so check out the video to see these eyes really shine!


witch1Next up is [controlmypad] with Blair the Witch Project. A normal trip to Home Depot turned paranormal when [controlmypad] spotted an awesome witch decoration. The free-standing mannequin had some basic animatronics and the all important manual trigger. [controlmypad] already had a discarded electric wheelchair. After replacing the chair batteries he modified it with a Sabertooth 2×32 Motor Controller and a standard radio control receiver. A spare channel was connected to Blair’s manual trigger. An aluminum tube joins the witch and the scooter. The hardest part of this hack was keeping Blair’s skirt out of the scooter wheels. Home Depot to the rescue! A simple hoop made of lawn edging plastic keeps the fabric and wheels apart.



[Alex Cordonnier] and his team participated in Boilermake 2015, a 24 hour Hackathon at Purdue University. The fruit of their labor is Trick or Tweet, the tweeting Jack-o’-lantern. Yes folks, we now have the internet of gourds. Hiding inside Trick or Tweet is a Raspberry Pi and a Pi Camera. The pumpkin itself is also a giant capacitive touch switch. Touching the pumpkin triggers a count down after which Trick or Tweet snaps a photo. It then adds some spooky Halloween overlays, a pun or two, and throws the whole thing up on twitter @PumpkinPiPics. [Alex] hasn’t uploaded the code yet, but we’re guessing it consists of a few Python scripts. Pretty awesome for 24 hours of work!


hariSometimes Halloween hacks take on a life of their own. That’s exactly what happened when [Hari Wiguna] sat down with a few parts he ordered from China. Happy Halloween 2015 is the result. [Hari’s] order included some potentiometers, a two color OLED display, and some Arduino clones. In no time [Hari] had three pots wired up to the Arduino’s analog inputs. The OLED quickly followed, displaying graphics via the Arduino’s I2C bus. He really wanted a Jack-o’-lantern though. It took a bit more tweaking, but eventually [Hari] was successful. The first pot sets eye size.  The second controls eye rotation. The third pot changes the width of Jack’s mouth. [Hari] has all the code for this hack up on his most recent project log.

Not spooked enough? If you want to see more Halloween projects, check out our newly updated Halloween hacks list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet; As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Raspberry Pi Halloween Voice Changer

[Dave Shevett] has spent a lot of time (more than a year) expanding his Technomancer costume along with the companion (Arduino-driven) magic staff. He found, however, he needed a way to get his voice out from behind the mask. If you are going to go through that much trouble, you might as well augment your voice at the same time, right?

[Dave’s] voice changer uses a Raspberry Pi which isn’t all that complicated. The Pi uses Linux, and Unix–the predecessor to Linux–has a long history of having little tools you can string together to do big jobs. So once you have a Pi and a sound card, the rest is just some Linux command line wizardry.

There’s a battery and a small portable amplifier to get that booming voice. Since you don’t want to lug a keyboard and monitor around to handle every reboot, [Dave] set the Pi up to run his voice-changing scripts on each reboot.

This is a great example of why old Unix programmers make small tools and use the shell to join them together. [Dave’s] voice changer is pretty much just some off the shelf parts and a  script so simple it hardly qualifies as programming in any real sense. In fact, it is essentially one line of “code”:

play "|rec --buffer 2048 -d pitch -300 echos 0.8 0.88 100 0.6 150 .5 band 1.2k 1.5k"

Sure, there is some street cred in embedded development to doing everything the hard way, but with the advent of cheap embedded Linux systems, why not take advantage of the tools where you can?

If you want a more roll-your-own approach, you can pick up your Arduino or break out an audio mixer (but good luck getting it in your costume).

Halloween Hood Has Hideous LED Gaze

Looking to create fear and dread with your Halloween costume? [Becky Stern] over at Adafruit has you covered, with her tutorial on building a mystical hood with LED eyes, perfect for your next Jawa, Black Mage, or Orko costume.

This creepy-looking creation is based around a Gemma controller driving two NeoPixel Jewels, small circular RGB LED boards. The Gemma drives the boards to slowly fade on and off for the required creepy eye effect, but it would be easy to create other lighting patterns.

Speaking of patterns, the tutorial also includes a sewing pattern for the hood, and plans for a 3D printed battery holder that would make the whole thing very easy to carry. If the eyes aren’t enough, how about adding an LED magic staff to complete your creepy ensemble? Or perhaps some light-up dinosaur spiky plates?

Do you have any good Halloween costume hack plans? Let us know in the comments, and we’ll put together a list of the best closer to the hideous day.

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“Stomach Shot” Halloween Costume

Halloween may have come and gone, but [Luis] sent us this build that you’ll want to check out. An avid Walking Dead fan, he put in some serious effort to an otherwise simple bloody t-shirt and created this see-through “stomach shot” gunshot wound.

The project uses a Raspi running the Pi Camera script to feed video from a webcam on the back of his costume to a 7″ screen on the front. [Luis] attached the screen to a GoPro chest harness—they look a bit like suspenders—to keep it centered, then built up a layer of latex around the display to hide the hard edges and make it more wound-like. Power comes from a 7.4V hobby Lipo battery plugged into a 5V voltage converter.

After ripping a small hole in the back of his t-shirt for the webcam and a large hole in the front for the screen, [Luis] applied the necessary liberal amount of fake blood to finish this clever shotgun blast effect.

Halloween Hack Night at Pololu

Have some servos and an Arduino lying around? It isn’t too late to get your freaky on! Last night, tech enthusiasts of Las Vegas gathered at Pololu Robotics to show off their hacks for a Halloween flavored edition of their bi-monthly robot club. These projects created by those in the community as well as the Pololu engineers themselves are fun and have a relatively short list of materials. So, if the examples below give you some inspiration, this is permission to Macgyver something together before your big Halloween party tonight…

roboFingersImpatient Severed Fingers – [Amanda] came up with a cute use for some mini servos and a zombie hand prop. The five severed fingers were attached to one end of a plastic rod. The other end was mounted to each of five servos which were laid out in the appropriate hand shape and attached to a fixed base. An Arduino running a basic sweep sketch animated the motors at slightly staggered intervals, creating a nice rolling effect. Even with the moving parts exposed this prop would be awesome to have on display, or set the ambiance with its continuous tapping…

deltaSpectorAngry Spectral Delta – [Nathan Bryant] made an actual costume for his delta robot from Robot Army. By attaching a small plastic skull to the end effector and draping a tattered piece of fabric over the rest of the mechanism he effectively transformed the delta into a little ghost with a sassy personality. The head swiftly bobbed about, all while staying parallel to the table… until it intermittently came unhinged and hung limply, which was a nice added effect!


exorcismBabyRobotic Exorcism Baby – This doll could turn its half skeleton, half baby face 180 degrees and then laugh at your fear. By attaching two servo motors together, [Jeremy] was able to create a pan and tilt mechanism which acted as the baby’s contorting neck and chattering jaw. The micro controller sending commands to the motors was hidden modestly under her dress.


shadowBoxStabby Animated Cardboard Shadowbox – Among the animatronic devices seen at the event was a shadowbox made by [Brandon] hidden in a dark conference room nearby. When one happened to walk past the seemingly unoccupied space, they’d glimpse the silhouette of an arm stabbing downward with a knife through a windowsill. Being lured in for further investigation you’d find that the shadow was being cast by some colored LEDs through a charmingly simple device. A cutout made from recycled card stock was attached to a single servo. This whole mechanism itself rocked back and forth slightly as the motor moved, which wasn’t intentional but added some realism to the motion of the stabby arm.

There were many interesting projects present last night ranging from remote-controlled skeletal arms to other reactive devices ready to deliver a scare. If you’re interested in knowing more, those made by the Pololu crew are documented on their blog. Since video does these projects better justice, you can check out a compilation of clips here:

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Hacklet 21 – Halloween Hacks Part 2

We asked, you listened! Last weeks Hacklet ended with a call for more Halloween themed projects on Hackaday.io. Some great hackers uploaded awesome projects, and this week’s Hacklet is all about featuring them. Every one of our featured projects was uploaded to Hackaday.io within the last 7 days.

masseffect2Mass Effect meets Daft Punk in [TwystNeko’s] 5-Day SpeedBuild Mass Effect Armor.  As the name implies, [TwystNeko] built the armor in just 5 days. Ethylene-vinyl acetate (EVA) foam was used to make most of the costume. Usually EVA foam needs to be sealed. To save time, [TwystNeko] skipped that step, and just brushed on some gold acrylic paint.  The actual cuts were based on an online template [TwystNeko] found. To top the armor off, [TwystNeko] used a custom built Daft Punk Guy Manuel helmet. Nice!


rat[Griff] wins for the creepiest project this week with Rat Bristlebot. Taking a page from the Evil Mad Scientist Labs book, [Griff] built a standard bristlebot based on a toothbrush and a vibrating pager motor. He topped off the bristlebot with a small rubber rat body from the party store. The rat did make the ‘bot move a bit slower, but it still was plenty entertaining for his son. [Griff] plans to use a CdS cell to make the rat appear to scamper when room lights are turned on. Scurrying rats will have us running for the hills for sure!

pumpkin[MagicWolfi] was created Pumpkin-O-Chain to light up Halloween around the house. This build was inspired by [Jeri Ellsworth’s] motion sensing barbot dress from 2011. Pumpkin-O-Chain uses the a similar RC delay line with 74HC14 inverters to make the LEDs switch on in sequence. He wanted the delay to be a bit longer than [Jeri’s] though, so he switched to 100K ohm resistors in this build. The result is a nice effect which is triggered when someone passes the PIR motion sensor.

pumpkinlite[Petri] got tired of his Jack-o’-lantern candles burning out, so he built his own Pumpkin Light. The light made its debut last year with a Teensy 2.0++ running the show. This year, [Petri] decided to go low power and switched to an MSP430 processor on one of TI’s launchpad boards. With plenty of outputs available on the Teensy and the MSP430, [Petri] figured he might as well use and RGB LED. The new improved Jack-o’-lantern can run for hours with no risk of fire.

We ccuth2an’t end this week without mentioning [Griff’s] updated Crochet Cthulhu Mask. We featured the mask in last week’s Hacklet, and called  [Griff] out for an update. Well, the final project is up, and it looks great! We’re sure [Griff’s] son will be raking in the candy this year!

It’s time for trick-or-treating, which means we have to end this episode of The Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!