With Independence Day just around the corner, American hackers are likely to find themselves blowing things up in the name of Independence. It’s all great fun but it can also be dangerous. The standard ignition method of “use a lighter and run away really fast” is not exactly safe. Instead of lighting your fireworks the old-fashioned way, why not follow [Facelesstech's] example and build your own infrared controlled remote igniter?

The first step was to decide how to actually ignite the firework fuse. [Facelesstech] had seen others use a car cigarette lighter for this purpose and he decided to follow in their footsteps. He started by removing the cigarette lighter from his own car and pulling it apart. Only one component was needed for this hack. The main heating element is a small disk with a “stem” on the end. If you apply 12V to the stem and attach the outer edge of the disk to ground, the igniter will quickly become hot.

[Facelesstech] originally thought he could just solder some wires to the device. However, the heating element gets so hot that the solder just melts every time it’s turned on. He then got creative and drilled a hole in a small block of wood that fits the heating element. The element is bolted into the wood and the bolt is used as a conductor for the electrical power.

The heating element is powered via a 12V relay. The relay is controlled by an Arduino Nano. The Nano allows two modes of operation. With the first mode, you simply press a button and the Nano will start a five second timer. The idea is to give you enough time to run to a safe distance before the firework is ignited. This isn’t much different from the old-fashioned method, but it does give you a slightly extended fuse. The second mode is where the project really shines. The Nano is also hooked up to an infrared receiver. This allows [Facelesstech] to press a button on an old television infrared remote control to active the igniter. This is a clever solution because it allows you to get to a safe distance without having to run a long wire. It’s also simple and inexpensive. Be sure to watch the video test of the system below.

[Thanks Dale]

[Dennis Adams'] wreath lights project looks pretty good. But he did some amazing coding to produce a whole set of interesting animated patterns that really seal the deal for the project. Don’t miss the video after the break where he shows off all of his hard work.

He started with a string individually addressable LEDs. These are the 12mm variety like what Adafruit sells (we’ve seen them popping up in a number of projects). To mount each pixel he tried a several different prototypes before settling on a ring that was 14″ in diameter. The design was laser cut from acrylic, with sets of staggered holes to host each ring of LEDs. The final touch was to add ping-pong balls to diffuse the light.

As we mentioned earlier, the light patterns really add the finishing touch to the project, but there is more functionality there too. [Dennis] rolled in the ability to monitor a Twitter feed with the wreath. When he gets a new tweet, a different animation will let him know about it.

[Thanks Chris]

[Jason] and his father took advantage of a week off of work over Thanksgiving to design and build a Christmas light decoration that can flash fancy patterns. He calls it the Uno Christmas Tree. It’s sixteen strands of lights draped between a pole and the ground to form the shape of a tree. The main controller is an Arduino UNO, but what really makes this work is a mechanical relay board with sixteen channels.

Using trigonometry they figured out that the decoration would be fifteen feet tall and have a five-foot radius at the base. A pipe was installed to act as the trunk, with an old toilet flange at the top and stakes at the bottom to anchor the lights. They all make their connections at the controller box using extension cords that were labelled with channel numbers. You can see the final product in the video after the break. But you’ll also want to watch the clip on [Jason's] blog which shares the sonic symphony created when the mechanical relays really start working.

This is just one example of several pairs of spooky eyes which light up [Vato Supreme's] bushes this Halloween. The quick and inexpensive build process make it a perfect diy decoration.

Each eye is made up of a ping-pong ball and an LED. But that alone won’t be very spook as the entire ball will glow rather brightly. So he spiced things up a bit by masking off the shape of a pupil and spraying the balls black. The vertical slit seen in white above will glow red like a demon in the night.

The LEDs are driven by an ATtiny85 running the Arduino bootloader. [Vato] found there was plenty of space two write code which fades the eyes in and out using PWM. This happens at random intervals for each of the four pairs he is driving.

We’ve seen a similar project that used oversized LEDs as the eyes. But we really like the idea of using a diffuser like this one. See it in action after the break.

Halloween is just around the corner, so of course we’re looking forward to a bunch of awesome costumes put together by Hackaday readers. In an effort to match his voice to his costume, [Phil Burgess] over at Adafruit (and former Hackaday alumnus) put together an Arduino-powered voice changer to give his voice the gravitas of [James Earl Jones] or the lightheartedness of a member of the Lollipop Guild.

If you’ve ever played with a turntable, you’ll know playing a 33 RPM record at 45 or 78 RPM turns your treasured copy of Dark Side of the Moon into a lighthearted aural experience with a pitch that is much too high. Likewise, playing a single at 33 or 16 RPM means those once dulcet tones are now recordings of tormented souls in an acoustic hell.

[Phil]‘s voice changer operates on the same principle by recording sounds from a microphone into a circular array and playing them back at a different rate; faster if the desired effect is a Munchkin, and slower if this year’s Halloween costume will be a Sith lord.

The completed build incorporates a 10k pot to dynamically change the timbre of the voice changer, as well as an Adafruit Wave Shield to play back a few pre-recorded sounds of lightsabers clashing. In all, a very cool project for your Halloween costume that’s also a very good introduction to DSP and real-time audio modifications with a microcontroller.