Coca-Cola’s New 3D Times Square Sign Invokes Inceptionism

September 2, 2017 by Steven Dufresne 58 Comments

Coca-Cola has updated their sign in Times Square, and this one has a mesmerizing 3D aspect to it, giving the spooky feeling you get from watching buildings curl up into the sky in the movie, Inception. That 3D is created by breaking the sign up into a 68’x42′ matrix of 1760 LED screens that can be independently extended out toward the viewer and retracted again. Of course, we went hunting for implementation details.

On Coca-Cola’s webpage listing the partners involved in putting it together, Radius Displays is listed as responsible for sign design, fabrication, testing and installation support. Combing through their website was the first step. Sadly we found no detailed design documents or behind-the-scenes videos there. We did find one CAD drawing of a Moving Cube Module with a 28×28 matrix of LEDs. Assuming that’s accurate then overall there are 1,379,840 LEDs — try ordering that many off of eBay. EDIT: One behind-the-scenes video of the modules being tested was found and added below.

So the patent hunting came next, and that’s where we hit the jackpot. Read on to see the results and view the videos of the sign in action below.

Continue reading “Coca-Cola’s New 3D Times Square Sign Invokes Inceptionism” →

An Environmentally Conscious, Solar-Powered Throwie

September 1, 2017 by James Hobson 24 Comments

The basic throwie is a a type of street art/graffiti/vandalism — depending on where you stand — consisting of a coin cell, an led, and a magnet taped together. Seeking to be a slightly more eco-friendly troublemaker, [Alaric Loftus] has kindly put together an Instructable on how to build a solar-powered throwie!

In order to be the best maker of mischief possible, [Alaric Loftus] tried a number of different products to find one that was hackable, supplied the right voltage, had the right form factor, and cheap enough to literally throw away. Turns out, garden path lights hit that sweet spot. Once [Alaric Loftus] has drilled a hole in the light and opened it up, de-soldering the stock LED, attaching some leads to the contacts and sticking it into the freshly-drilled hole is simply done. Hot-gluing a strong magnet on the bottom completes the throwie.

[Alaric Loftus] also advises that drilling the LED hole slightly smaller and sealing up any cracks with hot glue will strengthen its water resistance — because if it’s worth doing, it’s worth doing it right.

We’ve featured some really cool — even creepy — takes on the throwie concept, but please don’t contribute any further to e-waste buildup.

Control Thy LED

August 29, 2017 by Inderpreet Singh 50 Comments

In a previous article, I discussed LEDs in general and their properties. In this write-up, I want to give some examples of driving LEDs and comparing a few of the most commonly used methods. There is no “one size fits all” but I will try and generalize as much as possible. The idea is to be able to effectively control the brightness of the LED and prolong their life while doing it. An efficient driver can make all the difference if you plan to deploy them for the long-haul. Let’s take a look at the problem and then discuss the solutions. Continue reading “Control Thy LED” →

Color Sensor From An RGB LED And A Photocell

August 29, 2017 by Dan Maloney 27 Comments

When you need to quantify the color of an object, you’ve got quite a few options. You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to basics and build this reflective RGB sensor from an LED and a photocell.

The principle behind [TechMartian]’s approach is simplicity itself: shine different colored lights on an object and measure how much light it reflects. If you know the red, green, and blue components of the light that correspond to maximum reflectance, then you know the color of the object. Their sensor uses a four-lead RGB LED, but we suppose a Neopixel could be used as well. The photosensor is a simple cadmium sulfide cell, which measures the intensity of light bouncing back from an object as an Arduino drives the LED through all possible colors with PWM signals. The sensor needs to be white balanced before use but seems to give sensible results in the video below. One imagines that a microcontroller-free design would be possible too, with 555s sweeping the PWN signals and op-amps taking care of detection.

And what’s the natural endpoint for a good RGB sensor? A candy sorter, or course, of which we have many examples, from the sleek and polished to the slightly more hackish.

Continue reading “Color Sensor From An RGB LED And A Photocell” →

Clever Battery Holder Hack Makes Brilliant Earrings

August 15, 2017 by Donald Papp 6 Comments

A ‘googly eye’ with hole for LED leads on one side, slot for coin cell on the other. Black disk for pupil removed.

We love seeing a thing get used effectively for other than its intended purpose, and this DIY LED Earrings project is a great example. [IdunnGoddess] liked the idea of making light-up LED earrings powered by a small coin cell, but an enclosure and power connection for the battery were sticking points. The solution? A googly eye after a few minor modifications turned out to be perfect.

A googly eye resembles a thin, flat, hollow plastic bulb. Choose one that’s just a bit bigger than the coin cell, and cut a slot in one end and a small hole in the other. The LED leads go into the hole, and the coin cell slides into the slot. The result? A lightweight battery holder for an attached LED, and as a bonus the hacked googly eye is a clean and super smooth surface that can easily be painted or decorated to make it part of the design. The video embedded below demonstrates the process and showcases a few sample designs.

Continue reading “Clever Battery Holder Hack Makes Brilliant Earrings” →

Rushing The Design And Construction Of LED Centerpieces

August 11, 2017 by Donald Papp 7 Comments

‘Dragon Flame’ RGB LED table centerpieces, by [Alex Lao]

Sometimes the most important thing is getting something done.

[Alex Lao] was recently in such a situation. His sister was getting married and he designed, built, and delivered twenty RGB LED table centerpieces in a rush. There were no prototypes made, and when the parts arrived all twenty were built all at once over a single weekend. These table centerpieces are illuminated by RGB LEDs and battery-powered, but have an option to be powered by a wall adapter.

[Alex] helpfully shared some tips on reducing the production risks and helping ensure results in such a limited time frame. His advice boils down to this: reduce the unknowns. For Alex this meant re-using code and components from a previous project — even if they were not optimal — so that known-good schematic and footprint libraries could be used for the design.

From one perspective, the PIC32 microcontroller inside each lamp is overkill for an LED centerpiece. From another perspective, it was in fact the perfect part to use because it was the fastest way for [Alex] to get the devices working with no surprises.

For an added perspective on needing to get production right the first time on a much larger scale, be sure to check out getting an installation made up of 25,000 PCBs right the first time.

Know Thy LED

August 8, 2017 by Inderpreet Singh 82 Comments

The invention of the LED is one of the most important discoveries of our times. They are everywhere, from our flashlights to household lighting and television sets. We don’t need to tell you that a project with more blinkies is better than a project with fewer blinkies. But an LED is not simply an LED; the sheer variety of LEDs is amazing, and so in this write-up, we’ll take a closer look at how to choose the right LED for your next masterpiece. Continue reading “Know Thy LED” →