[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.

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.

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.

• T1, T2: 2N3904 transistors
• T3: LTR-3208E phototransistor
• LED1, LED2: 10mm diffused yellow LEDs
• R1: 5kohm resistor
• R2, R3: 50ohm resistors
• IC1: Atmel ATtiny13
• Source: 2xAA battery case with batteries

[aballen] wanted to light the jack-o’-lantern this year with something that didn’t actually require fire. After searching for a project that was cheap and yielded decent results, he ended up just making his own. This project utilizes an ATtiny13 and two LEDs, red and orange.  The overall build is quick and simple with some very basic code for the flickering. If you really want it more enclosed, there is this similar project using a cheap electric candle. Of course, not everyone has the time or desire to make one that is this realistic. You could always just go the easy way, no microcontroller required.

Why limit it to just lighting up your pumpkin though? Lets take a stroll through Evil Mad Scientist Laboratories hallways and see the Snap O Lantern or the dark detecting pumpkin and the Cyclonolantern.