Giant D20 Is A Critical Hit In More Ways Than One

September 24, 2017 by James Hobson 18 Comments

[Mikael Vejdemo-Johansson] is a member of the NYC Resistor hackerspace and an avid fan of a D&D themed improv theatre called The Campaign. To show his appreciation, he decided to gift them a Christmas present: a giant D20. The original plan called for integrated LEDs to burst alight on a critical hit or miss, or let out pulses if it landed on another face. Cool, right? Well, easier said than done.

[Vejdemo-Johansson] figured a circle of 4 tilt sensors mounted on the one and twenty face would be enough to detect critical rolls. If any of the switches were tilted beyond 30 degrees, the switch would close. He mounted eight ball-tilt switches and glued in the LEDs. A hackerspace friend also helped him put together an astable multivibrator to generate the pulses for non-critical rolls.

This… did not work out so well. His tilt sensor array proved to be a veritable electronic cacophony and terribly sensitive to any movement. That and some other electronic troubles forced a shelving of any light shows on a critical hit or miss. [Vejdemo-Johansson] kept the pulsing LEDs which made for a cool effect when shining through the mirrored, red acrylic panes he used for the die faces. Foam caulk backer rods protect as the die’s structure to stop it from being shattered on its first use.

Before The Campaign’s next show, [Vejdemo-Johansson] managed to stealthily swap-out of the troupe’s original die with his gift, only for it to be immediately thrown in a way that would definitely void any electronic warranty. Check out the reveal after the break (warning, some NSFW language)!

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Need A Night-Light?

September 19, 2017 by Lauren Faris 36 Comments

[Scott] created an LED candle in preparation for the big mac daddy storm (storms?) coming through. Like millions of other people in Florida, he was stuck at home with his roommates when an oncoming hurricane headed their way. Worrying about blundering about in the dark when the power inevitably went out, they set off to gather up all of the candles they had lying around. Realizing the monstrous pile of candles and matches looked more and more like a death wish, the decision was made to create a makeshift light out of what components they had on hand. Now, not having access to any outside sources for parts means that you are going to have a bare bones model.

That being said, this straightforward light only takes a couple of seconds to put together. Jury rig a couple of AA or AAA batteries up, then slap on a resistor, LED, and jumper to get that sucker running. Wrap electrical tape around the whole thing, or even try duct tape, whatever gets the job done. A little paper hat on top of it will diffuse the light and bada bing, bada boom, you’re all done. Generally though, soldering directly onto a battery is not a wise idea. So, if you want to get fancy, perhaps a better alternative is to have a battery casing as shown below.

This LED candle is a clear option if your home isn’t a micro warehouse for electronic components (apparently it is frowned upon to clog up your garage for projects), and you have limited time. However, if you have a number of extra minutes lying around before your windows blow in, see if you can top the brightest flashlight ever made (thus far). Continue reading “Need A Night-Light?” →

A Lightsaber, With Rave Mode

September 16, 2017 by James Hobson 21 Comments

How often after being exposed to Star Wars did you dream of having your own working lightsaber? These days — well, we don’t quite have the technology to build crystal-based weapons, but tailor-made lightsabers like redditor [interweber]’s are very much real.

Piggybacking off the Korbanth Graflex 2.0 kit — a sort of bare-bones lightsaber ready to personalize — [interweber] is using a Teensy 3.5 to handle things under the hilt. Instead of taking the easy route and cramming everything into said handle, a 3D printed a cradle for the electronics and speaker keep things secure. The blade is made up of two meters of APA102 LEDs.

As well as all the sound effects appropriate to ‘an elegant weapon for a more civilized age’, a cluster of buttons handle the various functions; , playing and cycling through music(more on that in a second), changing the color of the lightsaber — Jedi today, Sith tomorrow — enabling a flickering effect that mimics Kylo Ren’s lightsaber, color cycling, and a…. rave mode?

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We Are Now At DEFCON 2

September 16, 2017 by James Hobson 18 Comments

If you had a working DEFCON meter that reported on real data, would it be cool or distressing?

Before we get ahead of ourselves: no, not that DEF CON. Instructables user [ArthurGuy] is a fan of the 1983 movie War Games, and following a recent viewing –hacker senses a-tingling — he set to work building his own real-time display.

Making use of some spare wood, [ArthurGuy] glued and nailed together a 10x10x50cm box for the sign. Having been painted white already at some point, the paint brilliantly acted as a reflector for the lights inside each section. The five DEF CON level panels were cut from 3mm pieces of coloured acrylic with the numbers slapped on after a bit of work from a vinyl cutter.

Deviating from a proper, screen-accurate replica, [ArthurGuy] cheated a little and used WS2812 NeoPixel LED strips — 12 per level — and used a Particle Photon to control them. A quick bit of code polls the MI5 terrorism RSS feed and displays its current level — sadly, it’s currently at DEFCON 2.

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Super Simple Controller For Motorcycle LED Lights

September 9, 2017 by Anool Mahidharia 32 Comments

For automobiles, especially motorcycles, auxiliary lighting that augments the headlights can be quite useful, particularly when you need to drive/ride through foggy conditions and poorly lit or unlit roads and dirt tracks. Most primary lighting on vehicles still relies on tungsten filament lamps which have very poor efficiency. The availability of cheap, high-efficiency LED modules helps add additional lighting to the vehicle without adding a lot of burden on the electrical supply. If you want to add brightness control, you need to either buy a dimmer module, or roll your own. [PatH] from WhiskeyTangoHotel choose the latter route, and built a super simple LED controller for his KLR650 bike.

He chose a commonly available 18 W light bar module containing six 3 W LEDs. He then decided to build a microcontroller based dimmer to offer 33%, 50% and 100% intensities. And since more code wasn’t going to cost him anything extra, he added breathing and strobe modes. The hardware is as barebones as possible, consisting of an Arduino Nano, linear regulator, power MOSFET and control switch, with a few discretes thrown in. The handlebar mounted control switch is a generic motorcycle accessory that has two push buttons (horn, headlight) and a slide switch (turn indicators). One cycles through the various brightness modes on the pushbutton, while the slide switch activates the Strobe function. A status indicator LED is wired up to the Nano and installed on the handlebar control switch. It provides coded flashes to indicate the selected mode.

It’s a pity that the “breathing” effect is covered under a patent, at least for the next couple of years, so be careful if you plan to use that mode while on the road. And the Strobe mode — please don’t use it — like, Ever. It’s possible to induce a seizure which won’t be nice for everyone involved. Unless you are in a dire emergency and need to attract someone’s attention for help.

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1.5 Million Dollars Buys 850,000 LEDs And 29 Raspberry Pis

September 7, 2017 by Elliot Williams 83 Comments

You think you like RGB LEDs? Columbus, OH art professor [Matthew Mohr] has more blinkenlove than you! His ~~airport~~– convention-center-scale installation piece is an incredible 850,000 RGB LEDs wrapped around a 14-foot tall face-shaped sculpture that projection-maps participants’ faces onto the display. To capture images, there is also a purpose-built room with even illumination and a slew of Raspberry Pi cameras to take pictures of the person’s face from many angles simultaneously.

Besides looking pretty snazzy, the scale of this is just crazy. For instance, if you figure that the usual strip of 60 WS2812s can draw just about 9.6 watts full on, that scales up to 136 kW(!) for the big head. And getting the control signals right? Forgeddaboutit. Prof. [Mohr], if you’re out there, leave us some details in the comments.

(Edit: He did! And his website is back up after being DOSed. And they’re custom LEDs that are even brighter to compete with daylight in the space.)

What is it with airports and iconic LED art pieces? Does anyone really plan their stopovers to see public art? How many of you will fly through Columbus on purpose now?

Coin-Sized LED Control

September 5, 2017 by John Baichtal 10 Comments

EE and firmware developer [Enrico] had played with LEDs as a kid, burning out his fair share of them by applying too much current. With the benefit of his firmware chops, he set about creating a board that drives LEDs properly.

[Enrico]’s project centers around a Texas Instruments LM3405 buck controller. It accepts input voltage from anywhere from 3V to 20V and outputs up to 20V/15W to one or more LEDs. He built a ton of safety features into it like short-circuit and open-circuit immunity, temperature control, and auto-off switching when idle. He also created a LED board to test the maximum efficiency of the driver. It consists of four Luxeon Rebel ES diodes, one each RGB and W. The entire back of the LED board is copper, with a monster heat sink attached.

You can follow along with the Glighter-S project on Hackaday.io, or you can buy one of his boards from his Tindie store.

We’ve covered LED drivers extensively in the past, with posts on a simple 10-watt LED driver and how to design your own LED driver.