RFID Jacket Flashes the Crowd at Make Fashion 2014

RFID-DRESS

The [RADLab team] has created an eye-opening RFID jacket for Make Fashion 2014. For this project, [Dan Damron, Chris Zaal, and Ben Reed] of RADLab teamed up with designer [Laura Dempsey] to create a jacket which responded both to a dancer on the runway and the audience itself. RADLab stands for Radio Frequency Identification Application Development Lab, so you can probably guess that RFID was their weapon of choice for interaction. We’ve got a bit of RFID experience here at Hackaday, having recently used it at The Gathering in LA. The [RADLab team] didn’t skimp on processing power for this jacket. A BeagleBone Black running Debian controls the show. The BeagleBone receives data from a Thingmagic M6e 4 port UHF RFID Reader. The M6e is connected to 4 directional antennas. The BeagleBone responds differently depending on which RFID card is read, and which antenna reads it. With the data processed, the BeagleBone then issues commands to a teensy 3.0, which controls  WS2811 “Neopixel” addressable RGB LEDs sewn into the jacket.

During the fashion show, the jacket wearer danced with a second model who had RFID tags sewn into his t-shirt. The LED clusters on the front, back and sleeves of the jacket would light up, and change color and flash frequency based upon which tag and antenna got a read. Once the performance was over, the audience was encouraged to pick up tags and interact with the jacket themselves. The software was still very much beta, so the [RADLab team] monitored everything via WiFi and restarted the software when necessary.

[Read more...]

Making OLEDs In The Kitchen Sink

oled

When [Ian] first set out to create a homebrew OLED, he found chemical suppliers that wouldn’t take his money, manufacturers that wouldn’t talk to him, and researchers that would actively discourage him. Luckily for us, he powered through all these obstructions and created his own organic LED.

Since at least one conductor in an OLED must be transparent, [Ian] settled on ITO – indium tin oxide – for the anode. This clear coating is deposited on glass, allowing it to conduct electricity and you can buy it through a few interesting suppliers. For the cathode, [Ian] is using a gallium-indium-tin eutectic, an alloy with a very low melting point that allowed him to deposit a small puddle in his OLED stack.

With the anode and cathode taken care of, the only thing left was the actual LED. For this, [Ian] had some success with MEH-PPV, a polymer that is capable of electroluminescence. On top of this is a film of PEDOT:PPS, another polymer that serves to block electrons.

The resulting yellow-green blob of an OLED actually works, and is at least as good as some of the other homebrew semiconductor illumination projects we’ve seen around here. This is only a start, though, and [Ian] plans on putting a whole lot more time into his explorations of organic LEDs.

 

Reverse Engineering Candle Flicker LEDs, Again

LED

Flickering candle LEDs are seemingly everywhere these days, and like all fads, someone has to take a very close look at the engineering behind them.

[cpldcpu] had earlier taken a look at the controller chip in these candle flicker LEDs by measuring the current used and developing a statistical model of how these LEDs flicker. That’s math, of course, and much more fun can be had by decapsulating one of these flicker LED controller chips. It’s not very advanced tech; the LED controller is using a 1 or 2um process and a pair of RC oscillators, but it appears there could be a hardware random number generator in the silicon of this chip.

Earlier, [Cpldcpu] had taken a look at the tiny controller in these flickering LEDs and determined they used a linear feedback shift register to generate pseudorandom LED intensities. The new teardown seems to confirm that a linear feedback shift register is being used to drive the flickering LED.

Custom chips are only one way to skin a cat, or flicker a LED, and PICatout used the the tiniest PIC microcontroller (French, translation) to create his own flickering LED. Seems like making a few custom flickering LED throwies shouldn’t be too hard.

Breadboardable WS2812 LEDs

LED

Hackaday sees a ton of projects featuring the WS2812 series of digitally controllable RGB LEDs, in the form of bare chips, RGB LED strips, or some form of Adafruit’s NeoPixels. All these WS2812 LED products have one thing in common – they’re chip LEDs, making some projects difficult to realize. Now there’s a new member of the WS2812 family – a through-hole LED version - that should be available through the usual sources sometime later this year.

The key difference between these and the usual WS2812 LEDs is the packaging; these are 8mm LEDs with pins for power, ground, data in, and data out. With the preexisting libraries, this 8mm LED should work just the same as any other WS2812 LED.

Aside from a through-hole package, these new LEDs are very diffuse and aren’t as blinding as the normal chip LEDs. If you want to pick up a few of these LEDs, they’re available here, 13 LEDs for $15. There’s a lot of potential here for RGB LED cubes, something we hope to see sooner rather than later.

Ridiculously Over-Powered Quadrotor Spotlight Kills Battery, Blinds People

dscn0887

Flying quadrotors at night is awesome — but being in the dark tends to be a problem for not crashing them… Tired of not being able to get successful GoPro videos, [Diode] decided to strap a light to his quadrotor. A 3000+ lumen, 50W LED to be precise.

He found the 50W LED for $20 online with the driver! The only problem was it gets super hot. He salvaged a heat sink from an Xbox 360 which helps to keep the temperature at bay… but also increases the weight of the quad by a bit too much. Luckily his quadrotor is pretty powerful — but with the added weight, and 50W power drain, his flight time went from 15 minutes… to about 3 minutes.

Three of the most awesome minutes ever! Just watch the following video — the night-time possibilities are endless!

[Read more...]

Light Your Way to the Correct Resistor

click-and-see

Who doesn’t have issues with component storage (seriously, tell us your secret in the comments)? IF you can get your spare parts organized, it’s still quite difficult to figure out where you actually squirreled them away. Labeling drawers is one thing, but what if you have hundreds or thousands of drawers (we’re looking at you, every Hackerspace that’s been around for more than a few months). This project adds a digital cue to well-organized parts storage by lighting up the component drawer for stock selected from your computerized inventory (translated).

The idea is that all of your parts are assigned a drawer space on the computer. When you go into the index and select a part, the assigned drawer is illuminated by an LED. The setup here is a breakout board for an I2C LED driver which interfaces with a Raspberry Pi, but the concept should be easy to implement with just about any system.

Need help getting to the point where you’re organized enough to implement this? So do we. Maybe revisiting this storage roundup will help.

Hack All the Things in the Time You Save with This LED Pomodoro Timer

Do you want to use your time more productively but are tomato-averse? [Robin]‘s LED Pomodoro timer could be the perfect hack for you.

The Pomodoro Technique is a time management solution developed in the late 1980s. The basic idea is to spend a very focused 25 minutes performing some activity such as working or studying and then take a 5-minute break. Many of its proponents use a tomato-shaped kitchen timer to alert them to switch between the two states, but [Robin] wanted to make his own and learn along the way.

First, he wanted to use an ATtiny85 and learn about its features. Specifically, he used its timers, PWM, and low-power sleep mode. [Robin] used Charlieplexing to drive a total of six LEDs. When the timer starts, five yellow LEDs are driven high to indicate each 5-minute slice of work time. A red LED is lit during the 5-minute break.

[Robin] also explored compact PCB design and fabrication. All components are SMD and his board is 4cm square. [Robin] is using this SMD buzzer for discrete feedback. He included a footprint for a six-pin ISP header and programmed it with pogo pins. The timer is completely interrupt-driven: one click of the tactile button starts the work counter, and the buzzer sounds when time is up. A second click starts the break counter.

[Robin] has made everything available in his GitHub repo and encourages you to use it. Time’s a-wastin’!