Pumpkin Tetris Inspired By Our Own LED Jack-o-lantern

October 29, 2012 by Mike Szczys 12 Comments

The kids (or maybe their parents) are going to be lined up at [Nathan’s] front porch to get their turn at playing pumpkin Tetris. That’s right, he built a game of Tetris into a real pumpkin. We thought this looked quite familiar when we first saw it and indeed he was inspired by our own LED Matrix Pumpkin from two Halloweens ago. We love seeing derivative works and [Nathan] definitely make few great improvements to the process.

The matrix itself was wired in very much the same way we used, but he added an additional 58 LEDs to nearly double the size of the display. He used a paper grid and power drill to make room for the holes, but improved the visibility of the lights by sculpting square pixels in the skin of the fruit. But how does one control the game? The stem of the pumpkin is actually a joystick. One of the most innovative parts of the physical build was to use drywall anchors on the inside to mount the joystick hardware.

Don’t miss a demo video after the jump.

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Halloween Props: Ghoul In The Box Puts On A Pretty Good Show

October 29, 2012 by Mike Szczys 1 Comment

[Tim’s] ghoul in the box project has all the elements of a classic Halloween prop. He built it for last year’s display but we’re sure it will be a perennial favorite.

As the name implies, it’s modeled after a Jack-in-the-box toy. Fittingly, it’s decorated with bright, happy colors and includes a crank on the right side of the box. But you don’t need any man-power to make it work. Hidden in the red circle at the center of the front panel is a motion sensor. Walk in front of the box and one of two modes will be triggered. The crank may start up and a happy rendition of Pop Goes the Weasel plays. But as it nears the end of the song the tempo slows and the pitch drops as if running out of steam. It’s perfect foreshadowing for the vigorous bursting forth of the ghoul inside.

The demo after the break gives you a look at the operation, as well as the components used in the build.

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How NOT To Make Ground-hugging Fog

October 29, 2012 by Mike Szczys 35 Comments

Poor [Todd Harrison] spent all of Saturday and Sunday trying to make some ground-hugging fog for his Halloween decor. His fog machine hack turned out to be an utter failure. But he admits it and reports that he still had a lot of fun. Don’t feel bad [Todd], this happens to everyone from time to time. And anyone that has doubts about [Todd’s] skills need not look very far to find out that he does know what he’s doing.

The project started off with a theater-style fog machine. The problem is that this fills a room with a thin foggy-haze that doesn’t take shape outdoors. He wanted that ankle-deep graveyard effect and had seen several examples online that use a fog-machine with a bucked of dry ice. He though he’d just use his own bucket full of regular ice and salt water. Inside the bucket seen above there is a 15′ coil of copper tubing through which the fog machine’s output is passed. On the other side of the bucket there’s a plastic tube that goes to a sheet of plastic meant to distribute the cooled fog.

The problem here is that the fog machine puts out a hot mist. When it hits the ice bath the mist condenses into liquid form and that’s the end of the fog. As he attests in the video after the break, the dry-ice fog hack isn’t pumping out fog. It’s just using the heated steam to pump out carbon-dioxide vapor boiling off of the dry ice.

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A Collection Of Hands To Inspire Your Halloween Animatronics

October 29, 2012 by Mike Szczys 3 Comments

Jump scares are a lot of fun, but if you want to hold the attention of all those trick-or-treaters we’d suggest a creepy prop. One of the best choices in that category is a ghoulishly lifelike hand. You can draw some inspiration from this roundup of robot hands which Adafruit put together.

We’ve chosen four examples for the image above but there are more to be had than just these. In the upper left there is a laser-cut acrylic hand that actually features some force sensitive resistors on the fingertips to help implement some haptic feedback. This project was inspired by the hand seen in the lower right which uses flex sensors on a glove to control the bot’s movement. If you’re looking for something more realistic the 3D printed parts on the lower left are the best bet. But if you’re looking to put something together by Halloween night the offering in the upper right is the way to go. It’s hacked together using cardboard templates to cut out plastic parts and using polymorph to form joints and brackets.

Halloween Props: A Spooky Mirror

October 26, 2012 by Mike Szczys 5 Comments

This mirror will spook your guests with a variety of static and animated images. It includes a proximity sensor so the images will not appear until someone comes close enough to see themselves in the looking glass.

The electronic parts are quite easy to put together. There is a 32×32 RGB LED matrix mounted on the back of the mirror. It is driven by an IOIO board with some custom firmware written by [Ytai], the creator of that board who happens to live next door to [Alinke]. Where this starts to get interesting is when [Alinke] was working on the mirror to make the LEDs visible from the front. He used a razor knife to put hundreds of scratches in the varnish on the back. This lets just enough light through to see the LEDs, but keeps the mirrored surface reflective. See for yourself in the clip after the break.

The images are fed to the IOIO board by an Android device. We think this could have a lot of use after Halloween as a weather display or news ticker. Perhaps you could even feed it from your diy Android thermostat.

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Motion Sensing Fog Machine

October 25, 2012 by Brian Benchoff 1 Comment

Our favorite holiday is just around the corner, so there’s no surprise in seeing a few builds to scare children turning up in the tip jar. [Greg] also loves Halloween and apparently puts on a good show – he always uses a fog machine on his porch on All Hallow’s Eve, but triggering it at the right time is always a pain.

This year, [Greg] decided to build a motion-sensing fog machine. His machine featured a wired remote with a light to signal when the fog machine is ready and a button to start the pump. This remote runs at 120V AC, but [Greg] figured he could stick a small USB phone charger in the remote and power an ATtiny85 microcontroller.

The actual circuit is just a piece of perfboard, a large, old relay from Sparkfun, and a PIR sensor [Greg] picked up last year. Whenever the PIR detects movement, the Tiny85 activates the fog machine for 5 seconds and disarms itself for another 10, until it sees movement again. Just the thing for a little interactive ambiance for [Greg]’s Halloween display.

Video after the break.

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Electronic Demon Costume Is Surprisingly Unnerving

October 25, 2012 by Brian Benchoff 13 Comments

[Phil] over at Adafruit crashed last Sunday’s Show and Tell with an amazing demon costume that includes a voice changer and animated LED matrices for The Eyes and mouth. He just posted how he built this costume, but you’ve really got to Watch the video to see how awesome this build is.

Every demon needs a scary voice, so [Phil] repurposed his Arduino-based voice changer for this build. By being able to adjust the pitch of the demon’s voice with the turn of a knob, [Phil] goes from growling from the pits of hell to a demon with just a slightly annoying voice.

The Eyes make use of the Adafruit I2C LED matrix backpack. The eyes are wired to the same I2C address to prevent derping, but the three red mouth LED matrices are capable of displaying anything that fits on an 8×24 LED matrix.

The electronic portion of this build is mounted to a piece of plexiglas, which is in turn mounted to a mask [Phil] picked up from a craft store. Not really the best option considering the Halloween stores are now open for the year, but it does its job.

A Morphsuit – a spandex bodysuit – completes the build along with a few demon wings and horns. During Adafruit’s Show and Tell, [Phil] had electronic parts scattered all over his desk. To turn this into a costume, he’ll be mounting a small battery-powered speaker in a chest piece and stuffing all the electronics in a fanny pack.

It’s a very, very cool build that really steps up the game for Arduino-powered costumes. Check out the video after the break.

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