Hackaday’s Wikipedia Page Needs Help

June 23, 2014 by Mike Szczys 42 Comments

Hey, did you know we have a Wikipedia page? We didn’t either. Until today you could search for “Hackaday” and nothing would come up. That’s because it’s listed as “Hack a Day” and it hadn’t seen any TLC in at least a couple of years.

Here’s the great thing about Wikipedia, they want factual information so they discourage people with Conflicts of Interest from editing the pages. That means that having the Hackaday Staff edit the page is a sticky issue. I did indeed edit the page in order to add more sections (History, Hackaday Projects, Accolades) to make it easier for the community to work on the article. I disclosed this in the “Talk” section, requested the logo be uploaded, and began a discussion suggesting the page be moved.

Ethically this is about all I think we should do. It’s up to you now. We’d love to see a well-written, immaculately cited Wikipedia article for this great thing we’re all involved in.

Delving Deep Into High Speed Digital Design

June 21, 2014 by Will Sweatman 29 Comments

scope capture showing ringing affect in a high speed digital signal

In high speed digital circuits, fast doesn’t necessarily mean “high clock rate”. [Jack Ganssle] does an excellent job at explaining how the transition time of signals in high speed digital circuits is just as important as the speed of the signal itself. When the transition time is large, around 20 nanoseconds, everything is fine. But when you cut it down to just a few nanoseconds, things change. Often you will get a ringing effect caused by impedance mismatch.

As the signal travels down the trace from the driver and hits the receiver, some of the signal will get reflected back toward the driver if the impedance, which is just resistance with a frequency component, does not exactly match. The reflected signal then heads back to the driver where the impedance mismatch will cause another reflection. It goes back and forth, creating the ‘ringing’ you see on the scope.

[Jack Ganssle] goes on to explain how a simple resistor network can help to match the impedance and how these should be used in circuits with fast transition times, especially where you will be taking readings with a scope. As the scope probe itself can introduce impedance and cause the ringing.

In case you didn’t pick up on it, [Jack Ganssle] also happens to be one of the judges for The Hackaday Prize.

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Super Simple Way To Re-use Plastic Bottles

June 20, 2014 by James Hobson 42 Comments

One of our tipsters just sent in a fascinatingly simple trick for re-using plastic bottles and turning them into useful plastic string. It’s in Russian but between the translated English subtitles and visual demonstration, it’s quite easy to understand.

YouTube DIY survivalist [Адвокат Егоров] makes a lot of really cool tutorial videos on anything from making knives, forming parts with heated PVC pipe, making rings out of coins, or even how to increase the yield of your potato farm (what?). In this one he shows us how to make a very simple jig using a small piece of aluminum extrusion which can slice a plastic bottle into long ribbons which can then be used for many different things.

The jig is adjustable and you can easily produce different widths of the ribbon with ease. Why would you want plastic ribbon? He uses it as twine for tying things (it’s very strong), as well as a grip for his tools — simply by wrapping it around the handle of something tightly, and then using a hot air gun, you can form it in place to create a plastic handle.

Again, the video is in Russian, but you can translate the subtitles — it kind of helps.

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The Unity ‘Candle’ With A 30 Foot Flame

June 17, 2014 by Brian Benchoff 20 Comments

candle

[Quinn]’s friends were getting married, and while the couple wanted something like a ‘unity candle’ ceremony, they though simple candles were entirely unimpressive and ultimately not very entertaining for the guests. They decided a unity fireball would be a much better representation of their relationship, and were lucky enough to have a good friend that could build one.

The design of [Quinn]’s unity candle consisted of a control box with two key switches, a giant button, and the gigantic propane fueled candle set well back from the bride, groom, and guests at the ceremony. The candle itself releases the entire contents of an accumulator tank over a hot surface igniter, creating a thirty foot fireball without a visible pilot light, or the loud jet-like sound you would get from a traditional ‘poofer’.

As with all giant fireballs in front of an audience, safety was of the highest concern. [Quinn] didn’t use a full propane tank for this build, instead, a new, purged, and never used tank was used as an accumulator, storing just enough propane for one giant fireball. All the valves, regulators, and plumbing were rated for LP, and [Quinn] even filled out the proper forms and got the local fire department to sign off on it. It’s safer than [Caleb]’s Mario fire flower, but you still shouldn’t try this at home.

Video of the ceremony below.

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The In-Circuit SD Card Switch

June 8, 2014 by Brian Benchoff 20 Comments

SDISP

For nearly every problem, it’s possible to engineer a solution, even if you’re dealing with an extraordinarily niche problem that might only apply to yourself. [Joel] wanted to be able to program the microSD card in his BeagleBone with a new bootloader or file system without removing the SD card from the target board. This is a peculiar requirement, and it’s highly doubtful a product or even a circuit exists for such a function. This meant [Joel] would need to roll his own board to accomplish the task.

The board is remarkably simple, housing a single microSD socket, two expansion headers for a microSD sniffer for a computer and an embedded board, an FTDI header, and a pair of 4-bit multiplexer/demultiplexers. The operation of the device is fairly straightforward: send a signal down the FTDI cable, and the board switches the onboard SD card from one device to another.

[Joel] has a video of his screen that shows him pulling off in-circuit SD card reading and writing. You can check that out below.

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How A Maker Proposes

June 6, 2014 by James Hobson 30 Comments

proposal

[Sefi Attias] just sent us a heartwarming little video of how he proposed to his girlfriend [Tania] — using a little help from technology and other makers.

As a maker, [Sefi] was always building things which impressed [Tania], so he thought it was only fitting to make the proposal a one-of-a-kind maker experience.

He started by designing the engagement ring himself, to be 3D printed. It’s an amazingly complex little thing made up of the repeating words of the quote “I will betroth you to me forever”. It was almost too complex in order to print — but they managed to do it in wax, which allowed them to create a mold and then cast the final part in white gold. Once complete, they set a diamond in place to cap it all off.

The second step was the proposal, which was made possible using a quadrotor, a strip of RGB LEDs, and a long camera exposure. To show it off in real-time to [Tania] they setup a projector and screen on the side of the street, providing a surreal window into the park behind them. It was all made possible with the help from over 20 people from the XLN Makerspace and SkyLens (the quadrotor people).

Oh yeah, and she said yes.

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The Electrostatic Theory Of Metal Whiskers

May 27, 2014 by Brian Benchoff 90 Comments

wiskers Thanks to that wonderful ROHS stuff the EU passed more than a decade ago, we should be seeing a few high-profile failures of electronic components due to tin whiskers. These tiny hair-like extrusions of metal found most commonly in lead-free solder have destroyed billion dollar satellites and shut down nuclear reactors, despite no one knowing exactly how these whiskers form. Now there’s a new theory of metal whisker formation (abstract, unless you have access to APS) that actually has predictive power. Here’s the free version of the paper

[V. G. Karpov] from the University of Toledo suggest these whiskers are formed by differences in charge induced by metallurgical anomalies – contamination, differences in the grain of the solder, and oxides. Because of the difference in charge, the whiskers are extruded, for lack of a better word, out from the surface of the solder.

The theory of whisker growth is generally consistent with observed rates of whisker growth and other properties. With this theory, it should even be possible to grow tin whiskers. Why anyone would want to do that other than, ‘because it’s cool’ is anyone’s guess, but there you go.