LEDs turn the heat up on flameless pumpkin lights


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

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


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!

Before you throw out that pumpkin, make a dragon-o-lantern

Yes, it’s a little late for Halloween, but before you throw out that rotting gourd sitting outside your front door, how about planning for next year’s festivities with a dragon-o-lantern?

The first dragon-o-lantern that made its way into our tip line is a fire breathing dragon jack ‘o lantern built by [Aaron] for a pumpkin carving contest. The idea is simple; just carve a dragon head out of a pumpkin, insert candle, and spray the open flame with a can of Aquanet. Sure, it’s crude, but with a little engineering it could turn out to be a very, very cool build.

For a slightly more complex build, [Chris] built a fire-breathing jack ‘o lantern triggered by anyone saying the words, “trick or treat.” The key part of this build is a Microsoft Kinect, used for its voice recognition capabilities instead of its capacity to form a 3D depth cloud.

The fire portion of [Chris]’ build is controlled by an Arduino triggering a solenoid to dispense a small amount of fuel into the pumpkin shell. [Chris] doesn’t go over the construction of his ‘poofer,’ but any member of your local hackerspace should be able to show you how it’s done.

Videos after the break.

Continue reading “Before you throw out that pumpkin, make a dragon-o-lantern”

Halloween Hacks: A light and music show fit for [Jack Skellington]

Halloween Hacks Banner


[Greg] was looking for something to build using his recently acquired Arduino, and with Halloween approaching, he thought a cool light display would make a great project. He browsed around online and found this tutorial that shows how to build a chorus of singing pumpkins controlled by a computer’s parallel port. Since he didn’t have any computers with a parallel port kicking around anymore, he decided to try his hand at recreating it with an Arduino.

[Greg] gathered eight light up Jack-o-Lanterns, along with a handful of relays and other miscellaneous components. He wired up the relays to trigger each individual pumpkin’s built in light when switched by the Arduino. He sat down and carefully listened through “This is Halloween” from The Nightmare Before Christmas, choreographing each of the pumpkins to take on the voice of one of the movie’s characters.

When the show begins, the display transforms from a group of unassuming pumpkins with candles a-flicker to a chorus of ghouls extolling the virtues of Halloween.

It really is fun to watch, so be sure to check out the video below. If you’re looking to throw together a quick display before the big day rolls around, [Greg’s] source code and diagrams should get you headed in the right direction.

Continue reading “Halloween Hacks: A light and music show fit for [Jack Skellington]”

Halloween props: The honking pumpkin

_honking_pumpkin (Custom)

We see a lot of Halloween projects attempt to scare people. Many of them work with the element of surprise, jumping or flashing lights when triggered. We’ve noticed though, people have come to expect those things. This project is a real sleeper. No one expects a couple car horns to blare in their face  when they push the pumpkin’s nose. We know it would make us jump. You can see it in action as well as get the entire circuit from his site. We doubt his neighbors will find it as amusing as we do.

[via Hacked Gadgets]


[Todd] sent in his Hack-o’-lantern just a bit late for Halloween. He did a good job of working with the logo considering the difficulty it poses for pumpkin carving.  We would have been proud to have that on our porch for the kids to steal and smash in the road. Since others in the past have also done Hack a Day pumpkins, maybe this will spawn a Hack a Day pumpkin carving contest next year. If he had enough time to get the green LED working, it would have been that much sweeter; everything is better with electronics.

Flickering LED Circuit

Here’s a simple project for your Halloween celebration. The other day while looking through our box of Halloween decorations, we noticed that the incandescent lamp in one of the jack-o’-lanterns was burnt out. Instead of simply replacing the outdated bulb, we decided to build a small dark detecting circuit with 2 yellow LEDs based on this Evil Mad Scientist Laboratories design. After successfully building the circuit, we took the project one step further by incorporating an Atmel ATtiny13 microcontroller. The code switches the LEDs on and off randomly for a flickering effect and is based on this instructable. Below is the schematic we created in EAGLE and a parts list.

Continue reading “Flickering LED Circuit”