Wednesday, March 5, 2014 - 01:01Interrupt Free V-USB
[Tim's] new version of Micronucleus, Micronucleus 2.0, improves upon V-USB by removing the need for interrupts. The original Micronucleus was a very small implementation of V-USB that took up only 2KB. Removing the need for interrupts is a big leap forward for V-USB.
For those of you that do not know, “V-USB is a software-only implementation of a low-speed USB device for Atmel’s AVR® microcontrollers, making it possible to build USB hardware with almost any AVR® microcontroller, not requiring any additional chip.” One tricky aspect of using V-USB is that the bootloader requires interrupts, which can lead to messy problems within the user program. By removing the need for interrupts, Micronucleus 2.0 reduces the complexity of the bootloader by removing the need to patch the interrupt vector for the user program.
With the added benefit of speeding up the V-USB data transmission, Micronucleus 2.0 is very exciting for those minimal embedded platforms based on V-USB. Go ahead and try out Micronucleus 2.0! Leave a comment and let us know what you think.
Filed under: Microcontrollers
Tuesday, March 4, 2014 - 22:01Public Transportation Display
[Adrian] and [Obelix] wanted to have an easy way to know when to expect the public transportation, so they hacked an LED dot matrix display to show arrival times for stops near their dorm.
They found the display on Ebay with a defective controller which they replaced with an ATmega328p. They connected the display to the internet by adding a small TP-Link MR3020 router and connecting it to the ATmega328p via a serial line. Their local transportation office’s web page is polled to gather wait times for the stops of interest. All rendering of the final image to display to the dot matrix display is done on their PC, which then gets pushed through to the MR3020, which in turn pushes it out to the ATmega328p for final display.
[Adrian] and [Obelix] warn about setting proper watchdog timers on the display driver to make sure bugs in the controller don’t fry the dot matrix elements. Their ATmega328p dot matrix driver code can be found on [Adrian]‘s GitHub page.
Check out a video of the display in action after the jump.
Tuesday, March 4, 2014 - 19:00Retrotechtacular: Lighting the Way for Talkie Pictures with Optical Sound Recording
This week’s Retrotechtacular is a 1943 Encyclopædia Britannica film focusing on optical sound reproduction for motion pictures. Both the sound and the images are recorded on film, which is only affected by light. Therefore, the sound waves must be converted to changes in light.
This is done the way you might expect: the sound waves hit a microphone and the changes in current are amplified and used to control the intensity of light falling on the film. Three types of soundtracks are described and wonderfully demonstrated at the end of the film.
All three types are made from a series of thin bars of light, and the corresponding current value is represented by changes in either their length or their width. In the Unilateral Variable Area recording, the bars extend from the right side of the sound track. Bilateral Variable Area recorded bars emanate uniformly toward the edges from the center. In Variable Density recording, all of the bars extend from the left to right extremes, but their thickness varies.
Variable Density recording is done with a light valve, which contains a pair of delicate metallic ribbons in a magnetic field that move like shutters when the sound current flows through them. The light coming through to the film is varied by the slot created in the space between the ribbons. The light patterns are changed back to sound through a photoelectric cell, which converts the variations in light back to changing current. These changes are amplified and run through a loudspeaker. Be sure to watch to the end to catch a demonstration of the recording methods, set to what we’re pretty sure is Camille Saint-Saëns’ Danse Macabre.
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.
Filed under: Retrotechtacular
Tuesday, March 4, 2014 - 16:00Woodhouse Controls Your House, Avoids Danger Zone
[Pat] may not be the world’s most dangerous secret agent, but he does have Woodhouse taking care of his home. [Pat] has been upgrading his sonic screwdriver home automation system these past few months. Waking up to a chilly room led him to start hacking a thermostat interface. [Pat] found that his furnace only needed one 24VAC wire to be shorted to a common during a call for heat. [Pat] was lucky in that his thermostat was low voltage. While researching a thermostat hack, we made the painful discovery that our thermostat is 120VAC, so watch for that if you try this one at home.
[Pat] connected his thermostat leads to a relay controlled by a Raspberry Pi. The Pi would read a temperature sensor and set the relay accordingly. That was fine for a quick hack, but opening an SSH window to change the temperature isn’t the most convenient thing in the world. Enter an old Asus Transformer Prime tablet. [Pat] coded up an Android Holo style interface using AJAX along with HTML/CSS/jQuery and PHP. OpenMic+ constantly listens for voice commands, and fires them off to Tasker tasks as needed. He calls the results Woodhouse, and the interface is very slick. The tablet controls and graphs temperature, [Pat's] media center, and his lights. Woodhouse is even [Pat's] right hand man when getting ready for those intimate moments. We can’t wait to see what [Pat] comes up with next.
Filed under: home hacks
Tuesday, March 4, 2014 - 13:01TDOA (Time Difference of Arrival) Directional Antenna
We have posted articles in the past on directional antennas such as Yagi antennas used for transmitter hunting otherwise known as fox hunting. Those types of antennas and reception suffer from one major drawback, which is as you get close to the transmitter the S meter will go full scale. At which time the transmitted signal appears to be coming from all directions. To correct for this problem you need to use clever signal attenuators or change to a poor receiving antenna as well as tuning off frequency effectively making your receiver hard of hearing so that only the direct path to the transmitter is loudest.
There is another popular type of antenna that you can build yourself called a TDOA which stands for Time Difference of Arrival. [Byon Garrabrant N6BG] shared a short video tutorial on the functionality of his home built TDOA antenna. Effectively this is an active antenna that uses a 555 chip or, in [Byon’s] case, a PIC chip to quickly shift between two receiving dipole antennas at either end of a shortened yardstick. In his explanation you learn that as the antenna ends move closer or farther from the source a 640 Hz generated audio tone will go from loud to very soft as the antennas become equal distance from the source. This type of directional reception is not affected by signal strength. This means you can be very close to a powerful transmitter and it will still function as a good directional antenna.
The current circuit diagram, BOM and source code are all available on [Byon’s] TDOA page.
The reason [Byon] used a programmable PIC instead of the 555 for his design is because he wants to add a few more modifications such as feeding back the audio output to the PIC in order to programmatically turn on a left or right LED indicating the direction of the transmitter. Furthermore, he plans on adding a third antenna in a triangular configuration to programmatically control a circle of 6 LEDs indicating the exact direction of the signal. When he finishes the final modifications he can drive around with the antenna array on his vehicle and the circle of LEDs inside indicating the exact direction to navigate.
We look forward to seeing the rest of the development which might even become a kit someday. You can watch [Byon’s] TDOA video after the break.
Filed under: radio hacks
Tuesday, March 4, 2014 - 10:01RFID Jacket Flashes the Crowd at Make Fashion 2014
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.
Filed under: wearable hacks
Tuesday, March 4, 2014 - 07:00Coolant Hose Grippers Keep Your Components in Place
Whether you have shaky hands when working on tiny components, or just need more control and flexibility, we think this “third hand” gripper using coolant hose is an ingenious solution compared to the little metal ones you can buy.
Not surprisingly this isn’t an original idea. In fact, Sparkfun actually sells it as a kit. That being said… it’s rather expensive — especially when you can build [Frank Zhao's] version for less than $15.
He’s using a cutting board, three machinery style coolant hoses, and a handful of fasteners from the hardware store. You can use the accessories from a regular metal third hand, but [Frank] also shows us how to recreate them using a few washers, some steel strapping, and a wing nut and bolt.
[Mr. Zhao] is no stranger to Hack a Day either — we’d almost call him an inadvertent contributor we’ve shared so many of his hacks! Just take a look at his tiny USB business card, his awesome LED pocket watch, a detailed reflow oven build, or even his IR based augmented reality setup.
Filed under: how-to
Tuesday, March 4, 2014 - 04:00Forget Stopping Bullets – Vest Warms You While Stopping Taser
[Bruce Wayne][Shenzhen] wanted a garment that would protect him from a jolt, while keeping him toasty in the cold weather. Well that’s not it at all, these are merely two of his projects using the same material in different ways.
We’re going to start with the infrared image on the right. This is a vest with chest and back pieces made of carbon tape totaling two meters of the material swirled on each side. Hook it to a power source and the carbon tape warms the wearer. Portability is something of an issue as each “element” takes 36 W of power (3A at 12V). Click through for advice on how to interface the tape with the power source.
Onto the main event… avoiding electrical shock when you get all up in the grill of that mall cop you’re hated for years. [Shenzhen's] jacket is really just an ordinary long-sleeved coat. But he separated the lining at the bottom seam and used fusible material to hold the carbon tape in place. The carbon tape provides a better conductor than your skin, preventing the shock from stunning you as it was intended. This really is the thing of superheroes, or former editors who should have known better.
Filed under: wearable hacks
Tuesday, March 4, 2014 - 01:00Remote Control Anything With A PS3 Controller
When looking for a remote control for your next project, you might want to look in your living room. Wii controllers are a hacker’s favorite, but wagging an electronic wand around isn’t the greatest for remote control planes, cars, tanks, and multicopters. What you need for this is dual analog controls, something every playstation since the 90s has included.
[Marcel] created a replacement electronics board for the Sony DualShock 3 controller for just this purpose. With this board, an XBee, and an old controller, it’s easy to add dual analog control and a whole lot of buttons to any project using an XBee receiver.
The replacement board is based on the ATMega328p uC, includes a Lipo charge circuit and power supply, and inputs for the analog sticks and all the button boards inside the DualShock controller.
Yes, we have seen an earlier version of [Marcel]‘s project before, but this time he’s added a few new features – the rumble now works and thanks to multiple people unable or unwilling to spin a few boards, [Marcel] has put up an Indiegogo campaign.
Monday, March 3, 2014 - 22:00Atomic Powered Robots and Records Played With Optics
If you were a child of the 80′s or early 90′s you probably remember Magic Mike. He went by many names, but he always said the same thing “I am the atomic powered robot. Please give my best wishes to everybody!” [Oona's] version of Mike had been malfunctioning for a few years. He’d stopped talking! She decided he needed more input, so she disassembled Mike to reveal the flesh colored plastic box in the center of his chest. This talkbox was used as a sound module in several toys. Before the days of cheap digital playback devices, sounds were recorded in a decidedly analog fashion. [Oona] found that Mike’s voice and sound effects were recorded on a tiny phonograph record in his chest. The phonograph was spun up by an electric motor, but the playback and amplification system was all mechanical, consisting of a needle coupled to a small plastic loudspeaker. The system was very similar to the early phonograph designs.
Mike’s record contained two interwoven spiral tracks. Interwoven tracks is a technique that has been used before, albeit rarely on commercial albums. One track contained Mike’s voice, the other the sound of his laser gun. The track to be played would be chosen at random depending upon where the needle and record stopped after the previous play. The record completely sidetracked [Oona's] repair work. She decided to try to read the record optically. She started with a high resolution image (image link) of the record, and wrote some Perl code to interpolate a spiral around the grooves. The result was rather noisy, and contained quite a bit of crosstalk. [Oona] tried again with laser illumination using a Lego train set. Unfortunately the Lego train / laser system wasn’t smooth enough to get a good image. In the end she used a bit of Gimp magic and was able to pull better audio from her original image. We never did find out if she put poor Mike back together though.
Filed under: toy hacks
Monday, March 3, 2014 - 19:01Hot or Not? Find Out How to Calculate Component Heat and Why You Should
How hot are your key components getting? There’s a good chance you’ve built a project and thought: “Well I guess I better slap a heat sink in there to be safe”. But when working on a more refined build you really need to calculate heat dissipation to ensure reliability. This is actually not tough at all. The numbers are right there in the datasheet. Yes, that datasheet packed with number, figures, tables, graphs, slogans, marketing statements, order numbers… you know right where to look, don’t you?
Hackaday has you covered on this one. In under 10 minutes [Bil Herd] will not only show how easy these calculations are, he’ll tell you where to look in the datasheets to get the info you need quickly.
Above, [Bil] used his bench as a whiteboard to illustrate the thermal resistance equation. In this case each resistor symbol represents part of the heat dissipation. You must consider all places where heat can be transferred: (from left to right) the component die (junction) to the component case, the component case to a heat sink, and the heat sink to ambient air. He illustrates each of these dissipation points in the video.
An example of the junction-to-case is shown to the right. This is a TO-3 case which has had the lid cut off. It’s a much simpler way to look at a chip die than trying to decap a component with a plastic case.
Make with the Math Already!
Okay, okay, we’re getting there. The math is not hard… just multiplication and addition, so hang on a minute more.
Gather the following values: maximum power you plan to use with this component, maximum heat rating of the part, maximum ambient air temperature in which this component will be used, and the theta values from the datasheets. Theta, which is a measure of degrees per watt, is often listed as a symbol: Θ Multiply theta by the max wattage and you will know how much temperature to add to your equation
Datasheets: Finding Θ and Temperature
Because [Bil] does such a great job in the video we’re giving you the quick version here. Temperature generating components will include a maximum operating temperature like the one shown below (click through for full datasheet) which is for a linear regulator:
The theta for “Juntion-to-Case” is found a bit further down the same datasheet in the Electrical Characteristics table. Datasheets will also provide a “Junction-to-Ambient” value (also shown below but not used in our calculations) used to calculate how much power you can use without any type of active or passive cooling. This answers the question of: “do I need a heat sink?”.
Finally, you want to look at values from the heat sink being used. [Bil] looks at the datasheet of a heat sink which lists a thermal resistance of 25.8Θ with the chart below on the left showing how that number may be altered with moving air (a fan). The chart to the right covers the use of interface agents like thermal grease, and a mica pad (for electrical insulation) with thermal grease. Both of those values are circled but only one will be used in the calculation.
Putting It All Together
If we assume an ambient air temperature of 38 C (100 F) and a maximum power of 2 W all of the numbers we need have been collected.
Max Temp = Junction + Mica/Grease + Heat Sink + Ambient
Max Temp = (4Θ * 2W)º + (0.4Θ * 2W)º + (25Θ * 2W)º + 38º
Max Temp = 8º + 0.8º + 50º + 38º
Max Temp = 96.8º
The maximum temperature rating for this part is 125 C, which means that this part is being properly cooled. [Bil] goes one step further in the video, showing how to calculate how much more reliable the properly cooled part will be.
- Texas Instruments LM317-N Datasheet (PDF)
- Texas Instruments App Bulletin for mounting TO-3 packages (PDF)
- AAVID THERMALLOY 7173DG heat sink example
Monday, March 3, 2014 - 16:003D Printed Zipper Saves the Day!
[Amr] recently built a 3D printer and came across his first practical application for it – his jacket’s zipper broke!
What we like about this project is [Amr] goes through the entire design process to finished product in his video. He starts by showing us the failed zipper, explaining where and why it failed, and then identifies the design features he needs to keep in order to make a functional replacement. To help accomplish this he checks out the Wikipedia article on zippers which shows an excellent animation of what happens inside of the zipper.
Now confident in his knowledge of all things zipper, he begins to model his replacement using SolidWorks, which is an industry standard among 3D CAD packages — for more information on how to use SolidWorks, we’ve been covering it in our 3D Printering articles!
Once satisfied with his 3D model, he tries to print it, but since it’s so small it pops off the bed mid-print. He adds a brim feature to the part and then it prints perfectly, in just over 30 minutes. We’re not sure if it was his first design iteration, but the zipper works on his jacket first try!
Of course we know he could have gone into town and bought a replacement zipper — but where’s the fun in that? Have you ever repaired something trivial just because? Let us know in the comments!
Monday, March 3, 2014 - 13:01Gritz: An Open Source Speed Reading Tool
Here’s a hack to help you increase your reading speed. Gritz is an open source text file reader, which reduces the need to look around the screen. Words pop up one at a time, but at a configurable pace.
[Peter Feuerer] got the idea for Gritz from Spritz, a commercial product for speed reading. The creators of Spritz took three years to develop their software, and recently released a demo. They claim people can read at 1000 WPM using this technology. Spritz is taking applications for access to their APIs, which will allow developers to integrate the software into their own applications. However, a fully open source version with no restrictions would be even better.
Using Gritz, [Peter] claims to have read a book with a 75% improvement in his reading speed. He admits it’s not perfect, and there’s still much development to do. Gritz is written in Perl, uses Gtk2 for its GUI, and comes with instructions for running on Linux, OS X, and Windows. It’s released under the GPL, so you can clone the Github repo and start playing around with accelerated reading.
Filed under: lifehacks
Monday, March 3, 2014 - 12:00Searching For Makers In Washington DC
Despite there being an inordinate amount of techies and tech companies in the Washington, DC/Northern Virginia area, there aren’t really that many hacker/makerspaces, or really anywhere else for tinkering, building, and generally futzing around with a soldering iron. [Zach] thought it was time for a change and is now organizing the second Make DC an informal get together to show off your latest projects and builds. Here’s the best part: Hackaday is coming, and we’re bringing some sweet swag.
Right now [Matt] has two talks lined up focused on bringing APIs into the physical world. There’s space for plenty more speakers, so if you have something to show off be sure to sign up.
The event is scheduled for Wednesday, March 19, 6:30 PM, half a block away from the Dupont Circle Metro station. Be there. You’ll get a sticker at least.
Filed under: news
Monday, March 3, 2014 - 10:01Hacking Dell Laptop Charger Identification
If you’ve ever had a laptop charger die, you know that they can be expensive to replace. Many laptops require you to use a ‘genuine’ charger, and refuse to boot when a knock off model is used. Genuine chargers communicate with the laptop and give information such as the power, current, and voltage ratings of the device. While this is a good safety measure, ensuring that a compatible charger is used, it also allows the manufacturers to increase the price of their chargers.
[Xuan] built a device that spoofs this identification information for Dell chargers. In the four-part series (1, 2, 3, 4), the details of reverse engineering the communications and building the spoofer are covered.
Dell uses the 1-Wire protocol to communicate with the charger, and [Xuan] sniffed the communication using a MSP430. After reading the data and verifying the CRC, it could be examined to find the fields that specify power, voltage, and current.
Next, a custom PCB was made with two Dell DC jacks and an MSP430. This passes power through the board, but uses the MSP430 to send fake data to the computer. The demo shows off a 90 W adapter pretending to run at 65 W. With this working, you could power the laptop from any supply that can meet the requirements for current and voltage.
Monday, March 3, 2014 - 07:00USB Keyboard And Mouse For The PS4
If you’d like to play BattleCallSpaceMarine on the Playstation 4 with a keyboard and mouse – and have an unfair advantage over everyone else playing on a console – you’d normally be out of luck. Sony implemented a fair bit of software to make sure only officially licensed controllers are able to talk to the console. It took a while, but [Frank Zhao] has figured out why keyboard and mouse doesn’t work on PS4, and created a device to enable these superior input devices.
Sony engineers decided – or were told – that the PS4 shouldn’t be able to connect to any old USB device. To that end, they made the console issue challenges to a DualShock controller to make sure the official controller is always connected over Bluetooth.
[Frank]‘s device solves this problem by taking the USB output from a keyboard and mouse, doing the CRC calculations, and sending them out over Bluetooth. Because the PS4 constantly issues challenges and responses of the authentication procedure, a real DualShock controller needs to be connected to the device at all times. Still, if you want a keyboard and mouse on the PS4, this is the way to do it.
All the sources and layouts are up on [Frank]‘s github where you’re free to create your own. This isn’t a finished product quite yet; [Frank] still needs to do a redesign of the circuit. Judging from the response of his earlier attempt at keyboards and mice on the PS4, though, this may be a successful product in the works.
Filed under: playstation hacks
Monday, March 3, 2014 - 04:00The Stepper Driver Driver
The Stepstick and Pololu motor drivers are the heart of just about every Reprap electronics board, but they can go bad. The usual way of testing these things is to rig up a microcontroller on a breadboard, grab some cables, and wire something up. [Ken]‘s Easy Stepper Motor Controller is a much simpler solution to the problem of testing these drivers and could, with a bit of practice, be constructed on a single-sided homebrew PCB.
The Easy Stepper Motor Controller is a very simple board with connections to a motor, a power supply, and headers for a single Pololu or Stepstick motor driver. Two buttons and a pot control the rotation of the motor with the help of an ATtiny10, and jumpers for up to 16x microstepping are right there on the board.
There’s a video after the break showing what this stepper motor driver driver can do. It’s not much, but if you’re just testing a driver, it’s all you need.
Monday, March 3, 2014 - 01:00Hackaday Links: March 3, 2014
If you’re playing along with Twitch Plays Pokemon, you might as well do it the right way: with the smallest Game Boy ever, the Game Boy Micro. [Anton] needed a battery replacement for this awesome, discontinued, and still inexplicably expensive console and found one in a rechargeable 9V Lithium battery. You get two replacement cells out of each 9V battery, and a bit more capacity as well.
Every garden needs garden lights, right? What does every garden light need? A robot, of course. These quadruped “Toro-bots” react to passersby by brightening the light or moving out of the way. It’s supposed to be for a garden that takes care of itself, but we’re struggling to figure out how lights will do that.
Flexiable 3D prints are all the rage and now resin 3D printers are joining the fray. The folks at Maker Juice have introduced SubFlex, a flexible UV-curing resin. The usual resins, while very strong, are rock solid. The new SubFlex flexible resins are very bendable in thin sections and in thicker pieces something like hard rubber. We’re thinking custom tank treads.
Have a Google Glass? Can you get us on the list? [Noé] and [Pedro] made a 3D printed Google Glass adapter for those of us with four eyes.
Sunday, March 2, 2014 - 22:00Making OLEDs In The Kitchen Sink
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.
Filed under: chemistry hacks
Sunday, March 2, 2014 - 19:00Reverse Engineering Candle Flicker LEDs, Again
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.
Filed under: led hacks