Spinning Holographic POV Christmas Tree Of Death

December 27, 2022 by Joseph Long 11 Comments

[Sean Hodgins] really harnessed the holiday spirit to create his very own Giant Spinning Holographic Christmas Tree (of Death). It’s a three-dimensional persistence-of-vision (POV) masterpiece, but as a collection of rapidly spinning metal elements, it’s potentially quite dangerous as well. As [Sean] demonstrates, the system can display other images and animations well beyond the realm of mere holiday trees.

Initial experiments focused on refining the mechanical structure, bearings, and motor. A 1/2 horsepower A.C. motor was selected and then the dimensions of the tree were “trimmed” to optimize a triangular frame that could be rotated at the necessary POV speed by the beefy motor. A six-wire electrical slip ring allows power and control signaling to be coupled to the tree through its spinning central shaft.

The RGB elements are SK9888 LEDs also know as DotStar LEDs. DotStar LEDs are series-chainable, individually-addressable RGB LEDs similar to NeoPixels. However, with around 50 times the pulse width modulation (PWM) rate, DotStars are more suitable for POV applications than NeoPixels. The LED chain is driven by a Raspberry Pi 4 single board computer using a clever system for storing image frames.

If deadly rotational velocity is not your cup of tea, consider this slower spinning RGB Christmas tree featuring a DIY slip ring. Or for more POV, may we suggest this minimalist persistence-of-vision display requiring only a few LEDs and an ATtiny CPU.

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A Christmas-themed LEGO train engine and coal car

ESPHome Powers Festive Lego Train Set

December 27, 2022 by Robin Kearey 5 Comments

While the basic concept of LEGO bricks might have changed little since the mid-20th century, some components such as motors and sensors are still affected by technological progress and end up obsolete and unsupported. [Travis] ran into this problem when he was building a festive train setup and realized he didn’t have the speed controller to match his train engine. Without that part, the engine would only run at full speed and derail as soon as it hit a curve. The official speed controller had been discontinued and was hard to find, so [Travis] had to resort to building his own.

The basic components needed were an H-bridge driver to operate the motor and an ESP8266 to generate PWM signals. In order to keep the bricky appearance of the train engine intact, [Travis] hollowed out a few cheap imitation LEGO bricks to house the electronics. He also cut out slots for JST connectors, which are far more convenient to work with than LEGO’s brick-style connectors.

The ESP8266 runs ESPHome, which enables [Travis] to control the entire setup using Home Assistant. The train is programmed to run a few laps at the top of the hour and play choo-choo sounds from a mini MP3 player hidden in the coal car. That car also holds a standard AA battery holder to power the system, which makes it easy to swap the batteries without having to partially disassemble the train.

There are various ways to control LEGO creations using standard computer platforms: we’ve seen the ESP32 powering a LEGO tank, for instance. If you need a bit more computing power, there’s even an official LEGO Raspberry Pi HAT.

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Virtual Yule Log Brings Old Tradition To The Web

December 15, 2022 by Lewin Day 2 Comments

Yule Log broadcasts are a bit of an American tradition, though similar content has also been broadcast around the world. They consist of a video of a log burning in a fireplace, ideally merrily so, and often feature Christmas carols or other holiday songs to help create a festive mood. [Joshua Gross] wanted to bring that tradition up to date, and thus built a Yule Log website with the help of some creative technologists.

WebYuleLog.com, as the project is known, features several web-based recreations of the Yule Log concept. They are charming little creations built with different techniques, from the AI-generated to those hewn from simple, pure HTML and CSS. They range from cute 8-bit-esque tributes to burning firewood, to the ethereal and unrecognizable thought bubbles of an image-generating neural network. We’re pretty sure one of them is a oblique reference to an old Excel 97 Easter Egg, too.

It’s funny how much can be achieved within a modern browser window. Once upon a time, you were lucky to get a few GIFs and an obnoxious looping MIDI soundtrack.

This Gun Should Be Banned During The Month Of December

December 13, 2022 by Jenny List 10 Comments

Do you play Whamageddon? It’s a pastime for the month of December, something like the Game, in which you lose when you are exposed to the 1984 Wham! Christmas classic, Last Christmas. Such is the pervasive nature of Christmas music at this time of year, it’s extremely difficult not to encounter a bit of unexpected Wham! during the month. At Tkkrlab hackerspace in the Netherlands, they evidently take their Whamageddon seriously. Seriously enough it seems, to weaponise it, because one of their members has created a Wham! gun.

Starting with a compressed-air kit gun (we think that’s a sealant cartridge gun, for Anglophones) because of its comedy plastic-firearm-like appearance, they’ve put in an AliExpress audio sample player module and a speaker. Add a suitably hazard-warning paint job, and Wham! Any unwary visitor might be ambushed and lose their Whamageddon game before they can even pop the cap on a refreshing bottle of Club-Mate.

It’s all a bit of seasonal fun, but deadly serious if the dulcet tones of George Michael are anathema to you. Don’t get mad, get equal, never visit a Dutch hackerspace in December without first fixing your noise cancelling headphones.

Build Your Own Mini Fogging Cauldron

December 3, 2022 by Lewin Day 12 Comments

The best cauldrons are full of bubbling, steamy potions of great magical potential. We don’t have many of those in the real world, though, so sometimes we have to make do with a simulacra. [wannabemadsci] has built just that, with this fogging cauldron prop that uses no fog fluid or dry ice, running solely with water instead.

The heart of the build is a piezo element that vibrates at ultrasonic frequencies to atomize water. They’re available from websites like AliExpress complete with a driver circuit to energize the piezo element. The water is delivered from a wetted fiber wick, and quickly becomes a fog when the piezo is energized.

The disk was installed in a custom PVC water cup with the wetted wick, along with the electronics. The assembly was then lowered into an off-the-shelf plastic cauldron party favor to complete the look. The trick is to mount the piezo element sideways to get a nice-looking distribution of fog. A green LED was installed to light the cauldron from within.

The resulting effect is a sinister-looking glowing cauldron with a steady stream of fog emanating from the top. It’s a great piece of Halloween decor, and as a bonus, it doesn’t require any fancy chemicals to make it work. If you’re thirsty for more, be sure to check out the winners of last year’s Halloween Hackfest. Video after the break.

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Hanging Christmas Lights With No Ladder And No Fuss

December 3, 2022 by Lewin Day 25 Comments

Getting up on a ladder to hang Christmas lights is a great way to hurt yourself if you’re not careful, and winter conditions only add to the peril. One enterprising hacker has whipped up a neat way to avoid ladders entirely, by hanging their lights while planted safely on the ground.

The build uses hefty magnets and triangle eye bolts, attached at regular intervals to the string of Christmas lights. The magnets are used to hold the lights to metal roof siding, while the hooks allow the lights to be lifted into place using a hook on a large extendable pole. Washers, spacers, and screws are used to attach the magnets and hooks to the lights.

For a layout that follows the lines of a simple peaked roof, this hack works great. For more complicated installations, you might still have to climb up a ladder. We’ve featured great primers on getting started with advanced Christmas light displays before, if you’re looking to up your game.

Meanwhile, no matter how much you enjoy seasonal decoration brinkmanship, don’t even think about watching Deck the Halls (2006). Danny Devito has saved a lot of films, but he couldn’t save this. Happy holidays!

Bike-Riding Skeleton Stalks The Streets On Halloween

November 11, 2022 by Lewin Day 10 Comments

Stationary pumpkins and motionless skeletons aren’t enough to scare people these days. If you want to really create a fright on Halloween, you need something more convincing. This bike-riding skeleton from [rc jedi] might just do the trick.

A few neat tricks make this impressive build surprisingly simple in nature. Propulsion is via a scrapped electric scooter drivetrain hidden in the sidecar. This not only propels the rig, but the third wheel means there’s no need to do any fancy balancing work to keep the bike upright. Steering is via a big chunky servo mounted to the bike frame which controls the handlebars. Regular RC gear handles remote control of the steering and drive.

The skeleton itself was an off-the-shelf buy, that was modified to have more flexibility in its joints. The hands were attached to the handlebars, and the feet attached to the pedals, so it appears to pedal the bicycle as it moves down the road. A dog skeleton rides along in the sidecar as a spooky companion.

A skeleton prowling the streets by BMX is a wonderfully spooky sight. We’ve seen some other great skeleton builds before, too, from the canine to the musical variety. Video after the break.

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