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21 Nov 04:02

Raspis and Arduinos for FM Broadcast Streaming

by Brian Benchoff

radio

The biggest Internet provider in Portugal needed a system to turn FM broadcast stations in Angola, Cabo Verde, and Mozambique into a web stream. Like every good project, the people in charge of the engineering turned to Hackaday staples – Raspberry Pis, Arduinos, and TP-Link routers, all stuffed into an awesome modular rackmount cabinet

Each module in this gigantic rackmount system includes an Arduino, a Raspberry Pi, a Silicon Labs Si4705 FM receiver chip, and a TI USB audio capture chip that allows the Pi to turn the audio out from the radio receiver into an audio stream. All the Pis are connected to a 24 port Ethernet switch and to a separate master Raspi that converts data received from each module into an icecast stream.

The engineering behind each module is pretty impressive – they’re all hot swappable, have remote shutdown capability, and have voltage divider on the backplane to detect where in the rack it’s placed. It’s a very cool piece of engineering and a very cool example of using off-the-shelf hardware to do something that could be much, much harder.


Filed under: Arduino Hacks, radio hacks, Raspberry Pi
16 Nov 02:40

Substitutions

INSIDE ELON MUSK'S NEW ATOMIC CAT
14 Nov 16:28

radondoran: Bill Nye The Science Guy, “Atoms” (1997).















radondoran:

Bill Nye The Science Guy, “Atoms” (1997).

11 Nov 15:45

Puntins





Puntins

07 Nov 10:56

Augmented Reality Breadboarding

by Adam Fabio

ar-breadboard

[Scott] sent in this tantalizing view of the what could be the future of bread boarding. His day job is at EquipCodes, where he’s working on augmented reality systems for the industrial sector. Most of EquipCodes augmented reality demos involve large electric motors and power transmission systems. When someone suggested a breadboard demo, [Scott] was able to create a simple 555 led blinker circuit as a proof of concept. The results are stunning. An AR glyph tells the software what circuit it is currently viewing. The software then shows a layout of the circuit. Each component can be selected to bring up further information.

The system also acts as a tutor for first time circuit builders – showing  them where each component and wire should go. We couldn’t help but think of our old Radio Shack 150 in 1 circuit kit while watching [Scott] assemble the 555 blinker. A breadboard would be a lot more fun than all those old springs! The “virtual” layout can even be overlayed on real one. Any misplaced components would show up before power is turned on (and the magic smoke escapes).

Now we realize this is just a technology demonstrator. Any circuit to be built would have to exist in the software’s database. Simple editing software like Fritzing could be helpful in this case. We’re also not sure how easy it would be working with a tablet between you and your circuit. A pair of CastAR glasses would definitely come in handy here. Even so, we’re excited by this video and hope that some of this augmented reality technology makes its way into our hands.


Filed under: Virtual Reality
07 Nov 10:56

Guitar Amp Turned Tool Cabinet

by James Hobson

amp cabinet

While HANDMADE.hackaday was a rather ephemeral experiment, we still come across some mighty fine examples of handmade projects that we think deserve to grace the pages of Hack a Day. As is the case with this beautifully repurposed guitar amp turned tool cabinet.

After gutting the original amp, [Max] set to bending some 22ga steel plate into drawers. He enjoys using that particular gauge because its fairly easy to cut and bend, while still being rigid enough for most applications. Once content with the bending jobs, he attached ball bearing roller slides to the sides and installed the drawers. Making use of the original amp face for the top drawer he cleaned up all the edges and gave it some new paint — it’s a beautifully crafted example of what you can do with a bit of sweat and elbow grease!

And for the audiophiles, don’t worry — the amp wasn’t functional before it was cannibalized for its casing.

[Via Reddit]


Filed under: tool hacks
07 Nov 10:51

Homemade Nixie Tubes

by James Hobson

home-made nixie tubes

Do you love Nixie Tubes? Upset that they aren’t really manufactured anymore, and the cost of old ones is rising? Why not make your own? That’s exactly what [Dalibor] of the Czech Republic is up to, including blowing the glass tubes himself!

He’s chosen the Z568 nixie tubes to copy, as they are his favorite style of nixie. To create the display he has etched the digits and housing out of 0.3mm stainless steel sheet — which potentially means if he gets the hang of making the tubes, he could actually produce them to sell! To perform the glass blowing, he scored a Heathway glassblowing lathe off eBay – but unfortunately he hasn’t documented much of anything on making the glass tubes, which is too bad because we think that would be equally fascinating as the nixie displays themselves. On his first attempt with a properly sealed tube, the nixie worked and he even recorded striking voltage values very similar to industry tubes — not bad for something made in a backyard shed!

He has since then continued refining this art and is entering a glass-art contest called “When Prague Meets Shanghai” with a beautiful entry dubbed the ShanghaiTime Nixie Clock.

If this post seems vaguely familiar, it’s because this isn’t the first time we’ve posted an article about homemade nixie tubes, but we think [Dalibor's] is by far the most elegant! Stick around after the break to see one of his first test videos — You might even think he’s cheating, the tubes look so professional!


Filed under: misc hacks
04 Nov 19:37

GimBall Bounces off Trees and Comes Back for More

by Adam Fabio

gimball

We’ve seen a lot of flying robots over the years, and for many of them, intimate contact with a stationary object would be a very, very bad thing. [The Laboratory of Intelligent Systems], at EPFL in Switzerland designed GimBall to not only take impacts in stride, but to actually use them as navigational aids. This is similar to an insect bouncing off an obstacle in nature.

GimBall’s design is a bit of a departure from the norm as well. Contra-rotating airplane propellers provide thrust while countering torque. It appears that the propellers are driven by two separate brushless outrunner motors, which would allow for yaw control via mismatched torque. Directional control is provided by a 4 articulated vanes on the bottom of the craft. Standard RC servos move the vanes. While not as common as quadcopters today, this “tail sitting” design has been around for decades. The Convair XFY “Pogo” is a good example of an early tail sitter design.

What makes GimBall so novel is its exoskeleton. A carbon fiber gimbal encircles the entire craft. Around the gimbal is a geodesic sphere made up of carbon fiber rods and plastic joints. The sphere acts like a shock absorber, allowing GimBall to harmlessly bounce off objects. The gimbal ensures that impacts won’t upset the craft’s attitude. Check out the video after the break to see how these two systems form an impressive shell which completely separates GimBall’s chassis from the outside world. GimBall can actually use its shell to “rotate” around obstacles.

During a recent test, GimBall was unleashed in a forest with only a compass heading as guidance. It was able to travel several hundred meters, bouncing off trees and plants along the way.  [The Laboratory of Intelligent Systems] members hope that GimBall will one day be helpful in unstructured situations, such as searching for victims of building collapses.

[Thanks Jayson!]


Filed under: drone hacks
03 Nov 00:56

Corner of 2025 and Park Avenue!

nyc,DeLorean,back to the future,new york city

Submitted by: Unknown

02 Nov 22:53

Photo





02 Nov 22:31

Sweet Teenage Mutant Ninja Turtle Shell Backpacks | Geekologie

01 Nov 02:15

Photo





23 Oct 01:58

colorful-author: dacadaca: A FRIEND JUST POSTED THIS ON...



colorful-author:

dacadaca:

A FRIEND JUST POSTED THIS ON FACEBOOK AND I JUST

I DON’T EVEN WANT TO KNOW HOW AMAZING THIS KID WILL BE WHEN HE GROWS UP

i cant wait until this kid gets on tumblr

21 Oct 12:49

Walter is a Robot Head Built From Scratch.

by Adam Fabio

walter

[Chris] has put together a robot head that is impressive at first sight. [Chris’] robot, Walter II, becomes even more impressive when you realize that [Chris] built every single part from scratch. Many of Walter’s parts were created using machines [Chris] built himself. Walter is a robot neck and head. His upper neck joint is based upon three bevel gears.Two steppers drive the side gears. When the steppers are driven in the same direction, Walter’s head nods. When they are driven in opposite directions, the head turns. The end result allows Walter’s head to be panned and tilted into almost any position.

A second pair of motors raise and lower Walter’s neck via a chain drive. What isn’t immediately visible is the fact that a system of gears and belts maintains the tilt on Walter’s head as his lower neck joint is actuated. For example, if Walter’s head is facing directly forward with his neck raised, one would expect him to be facing the ground when the neck is lowered. The gear/belt system ensures that Walter will still be facing forward when the neck joint reaches its lower limit. All this happens without any movement of the neck motors. [Chris] definitely put a lot of thought into the mechanical design of this system.

The mechanics help keep the electrical system simple. Two Arduino Nanos run Reprap teacup firmware. This means that Walter’s native language is actually G-code. One Arduino controls the bevel gear joint (X and Y in the G-code). A third Arduino controls the neck raise/lower (Z in G-code). A tower of stepper drivers complete the system.  We think the head and neck would look great on top of a track drive system.  Number Five is Alive!

[Thanks Jon]


Filed under: robots hacks
20 Oct 00:05

You Don't Need Millions of Dollars

Masters of Doom is the story of John Carmack and John Romero creating the seminal games Wolfenstein 3D, Doom, and Quake.

Masters-of-doom-book-cover

It's an amazing work on so many levels – but primarily because of the exhaustive research the author undertook to tell this story.

To re-create the story of the Two Johns, I conducted hundreds of interviews over six years, often with each person on multiple occasions. After moving to Dallas in the fall of 2000 for research, I became known in offices, barbecue joints, and bars around town as “the guy writing the Book.” John Romero and John Carmack each spent dozens of hours in person answering my most picayune questions: how they were feeling, what they were thinking, what they were saying, hearing, seeing, playing. What they and others couldn’t recall, I unearthed from websites, newsgroups, e-mails, chat transcripts, and magazines (though I drew from some of these articles, I made a point of getting the gamers’ own versions of what happened as well). I also played a delirious amount of games: at home, online, and at a couple tournaments (yeah, I lost).

I spent six months transcribing all my taped interviews. From this material, I assembled a narrative of dialogue and description that re-creates the events as faithfully and accurately as possible. As often as appropriate, I told the story from each person’s point of view to give readers the different perspectives.

It's unusual to find a book about a contentious, complex friendship and business relationship that both parties sign off on – and even a decade later, regularly recommend to people interested in their personal back stories. But it is a testament to just how right Kushner got this story that both Romero and Carmack do. This is exactly the sort of meticulously researched, multiple viewpoint biography that you'd want to read about important people in your industry. In that sense, it's kind of the opposite of the Jobs biography, which I liked well enough, but it presented one viewpoint, and often in a very incomplete, sloppily researched way. I would kill to read a book this good about Jobs.

In a way, I grew up with these guys. I am almost exactly the same age they are. I missed the Wolfenstein 3D release because I was still in college, but come December 1993, there I was, bursting with anticipation waiting for the release of Doom along with every other early PC gamer. And who gave Doom its name? Oddly enough, Tom Cruise did.

I've had a lifelong love affair with first person shooters since encountering Wolf3D and Doom. I played about every Doom engine game there was to death. I even had a brief encounter with Romero himself on the modem based multiplayer hub DWANGO where I proverbially "sucked it down". And after the Internet hit around '95, I continued to follow Quake development obsessively online, poring over every .plan file update, and living the drama of the inevitable breakup, the emergence of GLQuake and 3D accelerators, and the road to Quake 3.

It is also an incredibly inspiring story. Here's a stereotypical group of geeky programmers from sketchy home backgrounds who went on to … basically create an entire industry from scratch on their own terms.

Shareware. Romero was familiar with the concept. It dated back to a guy named Andrew Fluegelman, founding editor of PC World magazine. In 1980, Fluegelman wrote a program called PC-Talk and released it online with a note saying that anyone who liked the wares should feel free to send him some “appreciation” money. Soon enough he had to hire a staff to count all the checks. Fluegelman called the practice “shareware,” “an experiment in economics.” Over the eighties other hackers picked up the ball, making their programs for Apples, PCs, and other computers available in the same honor code: Try it, if you like it, pay me. The payment would entitle the customer to receive technical support and updates.

The Association of Shareware Professionals put the business, largely domestic, between $10 and $20 million annually—even with only an estimated 10 percent of customers paying to register a shareware title. Forbes magazine marveled at the trend, writing in 1988 that “if this doesn’t sound like a very sound way to build a business, think again.” Shareware, it argued, relied not on expensive advertising but on word of mouth or, as one practitioner put it, “word of disk.” Robert Wallace, a top programmer at Microsoft, turned a shareware program of his called PC-Write into a multimillion-dollar empire. Most authors, however, were happy to break six figures and often made little more than $25,000 per year. Selling a thousand copies of a title in one year was a great success. Shareware was still a radical conceit, one that, furthermore, had been used only for utility programs, like check-balancing programs and word-processing wares. [Shareware] had never been exploited for games.

Does anyone even remember what shareware is? What is the equivalent to shareware today? Distributing software yourself on the Internet? Sort of. I'd say it's more analogous to the various app stores: Google Play, Apple App Store, Windows Store. Going directly to the users. But they found shareware games didn't work, at least initially:

When it came time to distribute the games, Scott took a long, hard look at the shareware market. He liked what he saw: the fact that he could run everything himself without having to deal with retailers or publishers. So he followed suit, putting out two text-based games in their entirety and waiting for the cash to roll in. But the cash didn’t roll; it didn’t even trickle. Gamers, he realized, might be a different breed from those consumers who actually paid for utility shareware. They were more apt simply to take what they could get for free. Scott did some research and realized he wasn’t alone; other programmers who had released games in their entirety as shareware were broke too. People may be honest, he thought, but they’re also generally lazy. They need an incentive.

Then he got an idea. Instead of giving away the entire game, why not give out only the first portion, then make the player buy the rest of the game directly from him? No one had tried it before, but there was no reason it couldn’t work. The games Scott was making were perfectly suited to such a plan because they were broken up into short episodes or “levels” of play. He could simply put out, say, fifteen levels of a game, then tell players that if they sent him a check he would send them the remaining thirty.

You know how game companies spent the last 5 years figuring out that free games with 100% in-app purchases are the optimum (and maybe, only) business model for games today? The guys at id had figured that all out twenty seven years ago. Those sounds you hear in the distance are a little bit of history repeating.

Id Software was more than a unique business model that gave almost all the power to the programmers. It was the explosive combination of shareware delivery with a particular genius programmer inventing new techniques for PC games that nobody had seen before: John Carmack. It may sound prosaic and banal now, but smooth scrolling platforming, texture mapped walls, lighting models, and high speed software 3D rendering on a PC were all virtually unheard of at the time Carmack created the engines that made them commonplace.

Carmack_Headshot_PR_660

Carmack, like Abrash, is a legend in programming circles, and for good reason. The stories in this book about him are, frankly, a little scary. His devotion to the machine borders on fanatical; he regularly worked 80 hour weeks and he'd take "vacations" where it was just him and a computer alone in a hotel room for a whole week – just for fun, to relax. His output is herculean. But he also realizes that all his hard work is made possible by a long line of other programmers who came before him.

Al had never seen a side scrolling like this for the PC. “Wow,” he told Carmack, “you should patent this technology.

Carmack turned red. “If you ever ask me to patent anything,” he snapped, “I’ll quit.” Al assumed Carmack was trying to protect his own financial interests, but in reality he had struck what was growing into an increasingly raw nerve for the young, idealistic programmer. It was one of the few things that could truly make him angry. It was ingrained in his bones since his first reading of the Hacker Ethic. All of science and technology and culture and learning and academics is built upon using the work that others have done before, Carmack thought. But to take a patenting approach and say it’s like, well, this idea is my idea, you cannot extend this idea in any way, because I own this idea—it just seems so fundamentally wrong. Patents were jeopardizing the very thing that was central to his life: writing code to solve problems. If the world became a place in which he couldn’t solve a problem without infringing on someone’s patents, he would be very unhappy living there.

In that spirit, Carmack regularly releases his old engines under GPL for other programmers to learn from. Don't miss Fabien Sanglard's epic deconstruction of the Doom 3 codebase, for example. That's only one iteration behind the current id engine which was used for Rage and (apparently) will be used for the upcoming Doom 4.

One of my very favorite quotes of all time comes at the end of the book.

Carmack disdained talk of highfalutin things like legacies but when pressed would allow at least one thought on his own. “In the information age, the barriers just aren’t there,” he said. “The barriers are self-imposed. If you want to set off and go develop some grand new thing, you don’t need millions of dollars of capitalization. You need enough pizza and Diet Coke to stick in your refrigerator, a cheap PC to work on, and the dedication to go through with it. We slept on floors. We waded across rivers.”

And indeed they did, as the book will attest. Both @ID_AA_Carmack and @romero are still lifelong, influential, inspiring members of the game and programming communities. They are here for the long haul because they love this stuff and always have.

The ultimate point of Masters of Doom is that today you no longer need to be as brilliant as John Carmack to achieve success, and John Carmack himself will be the first to tell you that. Where John was sitting in a cubicle by himself in Mesquite, Texas for 80 hours a week painstakingly inventing all this stuff from first principles, on hardware that was barely capable, you have a supercomputer in your pocket, another supercomputer on your desk, and two dozen open source frameworks and libraries that can do 90% of the work for you. You have GitHub, Wikipedia, Stack Overflow, and the whole of the Internet.

All you have to do is get off your butt and use them.

[advertisement] Hiring developers? Post your open positions with Stack Overflow Careers and reach over 20MM awesome devs already on Stack Overflow. Create your satisfaction-guaranteed job listing today!
20 Oct 00:00

Reverse Identity Theft

Leandro Pereira

History of my life.

I asked a few friends whether they'd had this happen, then looked up the popularity of their initials/names over time.  Based on those numbers, it looks like there must be at least 750,000 people in the US alone who think 'Sure, that's probably my email address' on a regular basis.
16 Oct 01:20

futureisfailed: 1381660201741.gif

16 Oct 01:19

goes54667752: iPhone cover KATANAiPhoneカバー...





goes54667752:

iPhone cover KATANA
iPhoneカバー 刀
現代を生きるサムライの必須アイテム。柄の部分はモバイルバッテリーになっています。クライアントとの打ち合わせも終わったし、さっそく部長に報告でござる。

08 Oct 14:51

No, Not the Bottom One! Whoa...Impressive!

Leandro Pereira

Jengato.

No, Not the Bottom One!  Whoa...Impressive!

Submitted by: Unknown

Tagged: gif , kittens , cute , jenga
08 Oct 03:15

Photo



08 Oct 03:10

Photo



06 Oct 14:30

09.30.2013

Archive
Cyanide and Happiness, a daily webcomic
06 Oct 14:08

(Please Don’t) Build a Jet Engine from a Toilet Paper Holder

by Adam Fabio

colin

Turbo charger Jet Engines have long been considered one of the holy grails of backyard engineering. This is with good reason – they’re hard to build, and even harder to run. Many a turbo has met an untimely end from a hot start or oil starvation. [Colin Furze] however, makes it look easy. [Colin] is a proponent of crazy hacks – we’ve featured him before for his land speed record holding baby carriage, and his pulse jet powered tea kettle.

In his latest video set, [Colin] takes a toilet brush holder, a toilet paper roll holder, a few plumbing fittings, and of course a small turbocharger from the scrap yard. Somehow he converts all of this into a working jet engine. The notable thing here is that there is no welding. Some of the joints are held together with nothing more than duct tape.

Calling this a working jet engine is not really an overstatement. As every backyard jet jockey knows, the first goal of DIY jets (aside from not hurting yourself) is self-sustaining. Turbines are spun up with air hoses, vacuums, or leaf blowers. The trick is to turn the fuel on, remove the air source, and have the turbine continue spinning under its own power. Once this happens, your engine is performing the same “Suck, Squeeze, Bang, Blow” combustion process an F-18 or a 747 uses.

All this doesn’t mean the engine can do anything useful beyond keep itself running. This is where the second goal of backyard jet engines come in – thrust. You need a usable amount of thrust before you can strap that engine to a go-cart and go cruising around the neighborhood.

[Colin’s] jet is built and tested over a two video set. the first outlines how to build it, and the second shows the jet running. As a safety note, [Colin] has hinted in the YouTube comments that there will be a third video in the series showing how he had an incident with a gas leak, and it led to him being put “out of action for a week”. Needless to say – don’t try this particular engine build at home.

[Thanks James!]


Filed under: Engine Hacks
29 Sep 14:19

Fire & Ice: A Walk Inside an Ice Cave Next to the Mutnovsky Volcano in Northern Russia

by Christopher Jobson

Fire & Ice: A Walk Inside an Ice Cave Next to the Mutnovsky Volcano in Northern Russia Russia landscapes ice glaciers

This amazing shot was captured last year by photographer Denis Budkov in an ice cave near the Mutnovsky volcano in an area of northern Russia. Known for an abundance of precipitation the area is often covered in several meters of snow and ice that cover mountain streams like this creating vast caves that look like something out of a science fiction movie. This particular cave was nearly 300m (980 ft.) long and several photographers in Budkov’s group also snapped a few amazing shots. The photographer also captured this jaw-dropping photo of some tourists in front of a volcanic explosion earlier this year. The power of depth of field, right? (via Russia Travel Blog)

21 Sep 10:33

Mario plays piano with a little help from Raspberry Pi

by Adam Fabio

mario-piano

[David] has created his own live robot band to play live versions of the music and sound effects of NES games. Most of us who grew up in the 80’s and 90’s have the music of Nintendo games burned into our brains. While there have been some amazing remixes created over the years, [David] has managed to do something truly unique. Armed with an emulator, some software prowess, and a pair of Raspberry Pis, [Dave] created a system that plays game music and sound effects on analog instruments. A Yamaha Disklavier player piano handles most of the work through a connection to a Raspberry Pi. Percussion is handled by a second Pi.  Snare drum, wood block, and tambourine are all actuated by a custom solenoid setup.

The conversion process all happens on the fly as the game is played. [Dave] says the process has about ½ second of lag when played live, but we’re sure that could be fixed with some software tweaks.

We especially like the inclusion of Super Mario Brothers 2, as the intro music seems to have been written for piano. There have been offline conversions before, but hearing (and seeing) the original music played “live” on a real piano is something special.

One note on the sound. If it sounds as if the piano is “stepping on itself” at times, it is. The Piano is handling both background music and sound effects. Mario’s jumps and skid sounds fall right in the same octaves as the music.

[via BoingBoing]


Filed under: musical hacks, nintendo hacks
20 Sep 11:41

Advanced Transcend WiFi SD Hacking: Custom Kernels, X, and Firefox

by Adam Fabio

ts-wifi-advanced

[Dmitry] read about hacking the Transcend WiFi cards, and decided to give it a try himself.   We already covered [Pablo's] work with the Transcend card. [Dmitry] took a different enough approach to warrant a second look.

Rather than work from the web interface and user scripts down, [Dmitry] decided to start from Transcend’s GPL package and work his way up. Unfortunately, he found that the package was woefully incomplete – putting the card firmly into the “violates GPL” category. Undaunted, [Dmitry] fired off some emails to the support staff and soldiered on.

It turns out the card uses u-boot to expand the kernel and basic file system into a ramdisk. Unfortunately the size is limited to 3MB. The limit is hard-coded into u-boot, the sources of which transcend didn’t include in the GPL package.

[Dmitry] was able to create his own binary image within the 3MB limit and load it on the card. He discovered a few very interesting (and scary) things. The flash file system must be formatted FAT32, or the controller will become very upset. The 16 (or 32)GB of flash is also mounted read/write to TWO operating systems. Linux on the SD card, and whatever host system the card happens to be plugged in to. This is dangerous to say the least. Any write to the flash could cause a collision leading to lost data – or even a completely corrupt file system.

[Dmitry] spent even more time fighting with kernel builds. In the end he did emerge victorious. He was able to bring up his own kernel on the WiFi SD card’s ARMv5 controller and run anything he wanted. He tested the system by booting up with X windows forwarding through an SSH tunnel over WiFi. He was even able to get Firefox running in X, albeit very slowly.  The card doesn’t even need to be in a host system – only power and ground are needed to boot and access it via WiFi.

After all this was done, [Dmitry] finally got a response back from one of Transcend’s support engineers.  They are “Uninterested” in complying with GPL, and he is “free to report this to any Linux organization” Ouch! That’s one of the most cavalier GPL violations we’ve seen in a long time.

Update: It looks like Transcend has added u-boot sources to their GPL package. However, [Dmitry] states in the comments that they are still missing kernel config and some of the module sources.


Filed under: ARM, linux hacks, peripherals hacks
15 Sep 11:57

Kites

by Wes + Tony

''Going every day hoping it gets sucked into a jet engine.''

Kites are just people wishing that they had birds as pets. That’s all.

11 Sep 01:42

PCB agitator from a broken CD-ROM drive

by Mike Szczys

pcb-agitator

Etching PCBs goes a lot better if you agitate the solution in order to carry away the dissolved copper and get fresh etchant to the area. With that in mind [Rohit Gupta] designed a mechanism in Sketch Up before realizing he was going about it the hard way. He ended up basing his agitator on a broken CD-ROM drive instead of starting from scratch.

He uses the CD sled from the drive, ditching the lens and its support structure. To get direct access to the motor that drives the tray he uses an L293D H-bridge chip. This is controlled by an MSP430G2231 microcontroller. The driver board seen in the upper right includes a voltage regulator, three status LEDs, and one user input switch. Once triggered, the sled will move back and forth, contacting an old mouse microswitch which acts as the limiting switch. We find it entertaining that [Rohit] prototyped the circuit on a breadboard, then used that success to etch the final circuit board (shown in the video below).

If you’ve been following the hacker creed and never getting rid of any junk you’ll have no problem finding a donor drive to make one of your own. But just in case you can’t get a hold of this hardware a similar agitator can be built using a hobby servo.


Filed under: tool hacks
10 Sep 12:01

Tell Us Wrestling is All Fake After Seeing a Dude Get Slammed into LEGO

Tell Us Wrestling is All Fake After Seeing a Dude Get Slammed into LEGO

Submitted by: Unknown

Tagged: ouch , gif , lego , fail nation , wrestling
10 Sep 11:09

Graffiti briefcase for stealth tagging

by Josh Marsh

briefcase-2

We’re floored by painter and engineer [Bob Partington's] graffiti briefcase, which proves how well art and tech can complement one another. Fear not, Arduino haters, [Bob]‘s case is an analog dream: no microcontrollers here.

The guts consist of 2 components: a linear drive system and a trigger assembly. The former takes advantage of a small RC motor with a chain drive which slides the can’s mounting unit along two stainless steel rods. The latter includes a custom wound solenoid plugged into a 24V cordless drill battery, which slams down 5 pounds of force onto the can’s nozzle to fire the paint.

This all fits into an otherwise inconspicuous looking briefcase to provide some urban camouflage. The final component is a stencil, which slides into a rectangular hole on the bottom of the case. The paint can sprays downward through the stencil and tags the ground at the touch of a brass button located near the handle.  [Bob] has plenty of other cool inventions you should check out that are less illegal. Or, stick it to the man by automating your tagging with Time Writer.

Thanks [David]


Filed under: hardware, misc hacks