Halloween Knock Box

October 20, 2013 by James Hobson 7 Comments

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[Kyle] has been an avid reader of HaD for a long time. In fact, he was inspired by a Halloween knock box from 4 years ago! He saved the link and finally this year, he went ahead and made his own.

So what is it anyway? Well, as the name implies, when you knock on it, it knocks back. And if you knock on it a special number of times, it’ll play a secret tune… It is a great little item to have at any Halloween event — and kids love it!

Design and function of the box is basically the same as the original, with a few modifications — most notably, swapping out the original PICAXE for an ATtiny85 microcontroller. [Kyle] even managed to find the lego skeleton and chains available on eBay. He’s put together a very thorough blog post on it and shared all the code and schematics — so if you’re looking for a last minute Halloween project, this might be it!

Stick around after the break to see the knocking in action!

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DIY Pneumatic Skeleton And Air Horn Gag To Scare Those Trick-Or-Treaters

October 19, 2013 by Todd Harrison 13 Comments

[Rick Osgood] has been busy making more scaring gags for Halloween. This week he’s sharing great ideas for an air horn and pneumatic jumping skeleton, both actuated by 24 V sprinkler valves. These two new gags can easily be activated using [Rick’s] cardboard floor plate switch and three 9 V batteries cleverly snapped together in series for a 27 V supply (we can’t resist dropping in this link to a 2196 V supply from 9 V batteries just for fun).

The air horn construction is quite unique using a latex balloon strategically located as a reed valve for the air to vibrate over as it rushes out making a very loud honking sound. [Rick] then connected his manual bicycle pump to an air supply so that when an air valve is actuated the bicycle pump handle with a skeleton wired to it pops up. It then lowers back down via a bleed hole in the air line. Both the air horn and pneumatic pop-up skeleton seem simple to construct and his tests show them functioning perfectly.

Being the air storage chambers are small the re-trigger setup seems too repetitive to be practical for a continuous stream of Trick-Or-Treaters. Perhaps one could hide an air compressor with a long feed line to supply the gags? Plus, using an air compressor would come in handy for other scary blasts of air. Of course you would want to lower the compressor’s output regulator to safe levels so you don’t risk blowing apart your pop-up skeleton rig or any pipes.

Follow along after the break to see how to build these two great gags and get some tips from Mr. Safety.

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Halloween Doorknocker Decoration Hack

October 8, 2013 by Marsh 8 Comments

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If you’re new to hacking, Halloween is a great excuse to get started, and [Chuck] has put together an inexpensive animated Halloween decoration that you can show off on your front door. After scoring a $5 plastic Halloween doorknocker from Wal-Mart, [Chuck] gathered together a small pile of components and then set about breathing some life (death?) into its scary but motionless face.

Though he opted to use a Digispark, you should be able to use any Arduino that is small enough to stuff inside the plastic head. [Chuck] cut some holes in the eyeballs and glued in two RGB LEDs, then cobbled together a quick-and-dirty mount in the mouth area to hold a small servo. The lights and the servo are wired to the Digispark, which turns the lights on and instructs the servo to slam the ring against the door. It’s is battery powered and currently has only two settings: on or off. This should be good enough to scare the kids for this year, but [Chuck] has plans to add a much-needed motion sensor and sound via a Bluetooth connection.

As simple as this build is, it could be just the thing to get you in the holiday spirit, or to introduce the young hacker in your home to the world of electronics and coding. Check out the short video of the doorknocker after the break, then swing by [Chuck’s] website for detailed build instructions and his Github for the source code. If you’re having trouble finding this doorknocker at Wal-Mart, [Chuck] recommends a similar one on Amazon. Don’t stop now! Make some Flickering Pumpkins too, or if you want a challenge, hack together your very own Pepper’s Ghost illusion.

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DIY Pressure Plate Switch For Your Haunted House

October 2, 2013 by Todd Harrison 17 Comments

Yes, its Halloween time again and the hacks are going to be crawling out of the woodwork for the rest of the month. [Rich Osgood] is off to a good start promising one hack every week until Halloween. Judging from this first project, a DIY pressure plate switch, we think there’s going to be a common theme to follow. [Rich] constructs his pressure plate for almost no cost using cardboard, tinfoil and duct tape. It couldn’t be easier, so make lots of these if your haunting project requires pressure plate triggers to activate any spooks. Judging by the cardboard construction it’s likely they will fail after multiple uses, but you can switch one out quickly requiring only two hookup wires and a bit of tape.

Hopefully we aren’t stealing [Rich’s] thunder by recommending using Xbee wireless remote sensors to covertly monitor guests or trigger spooktacular scares.

We will be keeping an eye out for [Rich’s] follow-up Halloween hacks. Join us after the break to watch the tutorial video on making homemade pressure plates.

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LEDs Turn The Heat Up On Flameless Pumpkin Lights

October 1, 2013 by Adam Fabio 19 Comments

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When tea lights just won’t do, why not move up to a 5 channel LED candle simulato r?

Halloween is fast approaching. Peter’s local hackerspace, The Rabbit Hole had a meeting to carve pumpkins and talk Halloween hacks. After seeing how poorly a tea light illuminated a medium size pumpkin, this hack was born. We’ve seen LED jack-o’-lantern hacks before, but this one was worth a second look.

In true hackerspace style, [Peter] used what was available to him. A PIC12F508 is the heart of the project. The 12X508/9 series has been around for at many years, and is still a great chip to work with. We remember using the ‘C’ version of this chip to bypass region locks on original PlayStation systems. [Peter] created a simple circuit with two basic modes. In “value mode” the 508 drives LED’s directly from its I/O pins. This limits the total output to 60mA. In “premium mode”, some 2N3904 NPN transistors are brought in to handle the current. This allows the PIC to drive up to 5 LEDs.

Candles can be tricky to simulate with LEDs. [Peter] used 5 independent 16 bit linear feedback shift registers to generate pseudo random bit streams. The effect is quite impressive. A “wind simulation” completes the illusion of a real flame. Continue reading “LEDs Turn The Heat Up On Flameless Pumpkin Lights” →

Flickering Pumpkin Lanterns

October 1, 2013 by James Hobson 19 Comments

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Halloween is coming and [Paulo] decided to make some flickering jack-o-lanterns by hijacking the flickering circuit of a cheap LED tea light to drive a much more powerful light!

He has tons of old 12V incandescent bulbs collecting dust, so he decided to make use of them for some holiday fun. He wondered if he could steal the circuit from the flickering LED tea lights and use them to drive the incandescents. Upon taking the LED tea candle apart, he discovered there was no circuit, as it was in fact embedded in the LED itself! Not to worry though, he simply integrated the flickering LED into his circuit! Coupling a capacitor with the LED, he used a transistor amplifier to take the signal, and then finally boosted it using a MOSFET to drive the light bulbs. He then powered the entire thing using an old laptop power brick. Nice one [Paulo]!

Do you have any cool Halloween hacks? Don’t forget to send them in to the tip line! For other pumpkin fun, check out last year’s Pumpkin Tetris!

Robotic Tentacles For A Disturbing Haunted House

September 16, 2013 by Brian Benchoff 9 Comments

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[ivorjawa] is putting on a haunted house this Halloween that we really don’t want to go to. His robot tentacle is already supremely creepy, and we’re assuming it will only be more frightening once it’s covered in fabric and foam rubber.

Each tentacle can move on two axes thanks to four steel cables running through this strange Geiger-esque contraption. In the base of the tentacle are two stepper-motor driven cylinders that take up slack on one cable and draw out another cable. Two of these control boxes, driven by a stepper motor and an Arduino motor shield, allow the tentacle to reach out and grab in any direction. You can check out the mechanics of the build on [ivorjava]’s flickr

On a semi-related note, even though we’re more than a month out from Halloween, we should have more Halloween builds in our tip line by now. If you’re working on one, don’t be afraid to send it in, even if you’re just showing off a work in progress.

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