leds

160 Articles

Hackaday Podcast 045: Raspberry Pi Bug, Rapidly Aging Vodka, Raining On The Cloud, And This Wasn’t A Supercon Episode

December 6, 2019 by 5 Comments

Hackaday editors Mike Szczys and Elliot Williams talk over the last three weeks full of hacks. Our first “back to normal” podcast after Supercon turns out to still have a lot of Supercon references in it. We discuss Raspberry Pi 4’s HDMI interfering with its WiFi, learn the differences between CoreXY/Delta/Cartesian printers, sip on Whiskey aged in an ultrasonic jewelry cleaner, and set up cloud printing that’s already scheduled for the chopping block. Along the way, you’ll hear hints of what happened at Supercon, from the definitive guide to designing LEDs for iron-clad performance to the projects people hauled along with them.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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Beam Me Up To The PCB Space Ship

October 19, 2019 by 15 Comments

This project would fit in perfectly with #BadgeLife if someone could figure out a way to hang it from their neck. Inspired by Star Trek’s Starship Enterprise, [bobricius] decided to design and assemble a miniature space ship PCB model, complete with 40 blinking LEDs controlled by an ATtiny85.

While the design uses 0603, 0802, 3014, 4014, and 0805 LEDs, some substitutions can be made since the smallest LEDs can be difficult to solder. The light effects include a green laser, plasma coils, a deflector with scrolling blue LEDs, and the main plate and bridge for the space ship.

The LEDs are controlled by charlieplexing, a technique for driving LED arrays with relatively few I/O pins, different from traditional multiplexing. Charlieplexing allows n pins to drive n2−n LEDs, while traditional multiplexing allows n pins to drive (n/2)2 LEDs. (Here is the best explanation of Charlieplexing we’ve ever seen.)

Especially with the compiled firmware running on the MCU, the PCB model makes for an impressive display.

The only catch? Your Starship Enterprise can’t actually fly.

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Infinity Icosahedron Is Difficult To Contemplate Even Looking Right At It

February 17, 2019 by 13 Comments

Cubes and pyramids are wonderful primitive three-dimensional objects, but everyone knows that the real mystical power is in icosahedrons. Yes, the twenty-sided polyhedron does more than just ruin your saving throws in tabletop RPGs – it can also glow and look shiny in your loungeroom at home.

[janth]’s build relies on semitransparent acrylic mirrors for the infinity effect, lasercut into triangles to form the faces of the icosahedron. The frame is built out of 3D printed rails which slot on to the acrylic mirrors, and also hold the LED strips. [janth] chose high-density strips with 144 LEDs per meter for a more consistent effect, and added frosted acrylic diffusers to all the strips for a clean look with less hotspots from the individual LEDs.

An ESP32 runs the show, and the whole assembly is epoxied together for strength. The final effect is very future disco, and it’s probably against medical advice to stare at it for more than 5 minutes at a time.

The infinity effect is a popular one, and we’ve seen a beautiful cube build by [Heliox] in recent times. Of course, if you do manage to build an actual portal through time and space, and not just a lamp that looks like one, be sure to send us a tip. Video after the break.

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Let’s Look At Some Cool Old LEDs

December 14, 2018 by 17 Comments

LEDs are now a mature technology, with all manner of colors and flavors available. However, back in the 1970s, it was early days for this fledgling display tech, and things looked very different. [IMSAI Guy] happened to work at the optoelectronics division of Hewlett-Packard during their development of LED displays, and has a handful of prototypes from those heady days.

The video is a great look at not only vintage display hardware, but also rarely seen prototypes that seldom left the HP offices. Matrix, 7-segment and even 16-segment devices are all in attendance here. There’s great macro photography of the packages, including the now-forgotten bubble displays as well as hermetically sealed glass packages. The parts all have a uniquely 1970s look, drenched in gold plating and otherwise just looking very expensive.

The followup video breaks out the microscope and powers up the displays. [IMSAI Guy] shares some useful tips on how to best tinker with unknown LED parts, as well as knowledge about the chemical compounds and manufacturing processes involved in LED production. If you don’t know your III-V compounds from your II-VI compounds, prepare to learn.

It’s always interesting to take a look back, and even better to get a peek at the experiments of engineers of the past.

If you’re wondering about applications of this hardware, we’ve seen messageboards and watches before. Video after the break.

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Ghost Rider Costume Is Smoking Hot

October 26, 2018 by 20 Comments

It’s that spooky time of year once again, with pumpkins and cobwebs as far as the eye can see. This year, [Mikeasaurus] has put together something really special – a Ghost Rider costume with some amazing effects.

The costume starts with the skull mask, which started with a model from Thingiverse. Conveniently, the model was already set up to be 3D printed in separate pieces. [Mike] further modified the design by cutting out the middle to make it wearable. The mask was printed in low resolution and then assembled. [Mike] didn’t worry too much about making things perfect early on, as the final finish involved plenty of sanding and putty to get the surface just right. To complete the spooky look, the skull got a lick of ivory paint and a distressed finish with some diluted black acrylic.

With the visual components complete, [Mike] turned his attention to the effects. Light is courtesy of a series of self-blinking LEDs, fitted inside the mask to give the eye sockets a menacing orange glow. However, the pièce de résistance is the smoke effect, courtesy of a powerful e-cigarette device and an aquarium pump. At 225W, and filled with vegetable glycerine, this combination produces thick clouds of smoke which emanate from the back of the wearer’s jacket and within the skull itself. Truly stunning.

[Mike] reports that the costume is scary enough that he has been banned from answering the door as Ghost Rider. We think it’s bound to be a hit, regardless. For another epic mask build, check out the Borderlands Psycho. Video after the break. Continue reading “Ghost Rider Costume Is Smoking Hot” →

Unphotogenic Lighting As A Feature

September 12, 2018 by 13 Comments

Have you ever taken a picture indoors and had unsightly black bars interrupt your otherwise gorgeous photo? They are caused by lighting which flickers in and out in its normal operation. Some people can sense it easier than others without a camera. The inconsistent light goes out so briefly that we usually cannot perceive it but run-of-the-mill camera phones scan rows of pixels in sequence, and if there are no photons to detect while some rows are scanned, those black bars are the result. Annoying, right?

What if someone dressed that bug of light up as a feature? Instead of ruining good photos, researchers at the University of California-San Diego and the University of Wisconsin-Madison have found out what different frequencies of flicker will do to a photograph. They have also experimented with cycling through red, green, and blue to give the effect of a poorly dubbed VHS.

There are ways an intelligent photographer could get around the photo-ruining effect with any smartphone. Meanwhile DSLR cameras are already immune and it won’t work in sunlight, so we are not talking about high security image protection. The neat thing is that this should be easy to replicate with some RGB strips and a controller. This exploits the row scanning of new cameras, so some older cameras are immune.

PCB Junk Drawer Turned Into Blinky Mosaic

August 16, 2018 by 7 Comments

We’ve all got a box full of old PCBs, just waiting to be stripped of anything useful. [Dennis1a4] decided to do something with his, turning it into an attractive mosaic that he hung on the wall of his new workshop. But this isn’t just a pile of old PCBs: [Dennis1a4] decided to use the LEDs that were on many of the old boards, creating a blinky junk build. That’s kind of neat in itself, but he then decided to go further, building in an IR receiver so he could control the blinkiness, and a PIR sensor that detected when someone was near the mosaic.

This whole setup is controlled by an ATMega328p  that is driving a couple of PCF8575 port expanders that drive the LEDs. These blink in Morse code patterns. [Dennis1a4] also used an array of DIP switches on one of the boards to randomize the patterns, and wired in a pizeo buzzer on another board to make appropriate bleepy noises.

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