Hack a Day
Lord Vetinari’s clock strikes again

Inspired by the maddening timepiece from Discworld, this clock keeps time, but anyone watching the seconds tick by may be mentally unstable for it. [Renaud Schleck] built the stuttering clock using very few components. He undertook the build after being inspired by the version which [Simon Inns] built.
The clock itself is a run-of-the-mill item which uses one battery to keep time. We’re always impressed by how these dirt-cheap things remain so accurate over the long haul — but we digress. The method of attack uses coil injection to drive the hands. [Renaud] used one of the microcontrollers from the MSP430 Launchpad, along with the clock crystal which also shipped with the kit, to gain control of the mechanism. The crystal triggers an interrupt which does the actual time-keeping. The seconds hand is driven rather sporadically based on an algorithm explained in his write-up.
You can watch the uneven ticking in the video after the break. Despite that visually disturbing functionality, the short and long ticks balance each other and the correct time continues to be displayed.
[via Reddit]
Filed under: clock hacks
Layer One: a call for papers
It is that time of the year again! Layer one, the annual security conference is just around the corner. They’ve issued their call for papers so if you have something interesting, you’ll want to get a hold of them. If you haven’t heard of the conference before, take a few seconds to just stroll back in time and see some of the cool stuff they’ve shown off. We love seeing their cool hackable badges every year and we know this year won’t be any different.
Filed under: cons
Add speed control to a DIY CNC machine

[Jesse Merritt] bought a manual speed controller for his router. It’s used in the CNC mill he build and he figured, why not add the ability for the computer to control the speed.
The speed controller is a $20 unit from Harbor Freight. It comes with an On/Off switch and knob which adjusts the power going to the router. [Jesse] pulled off the knob and milled a gear which takes its place. The second gear is attached to the horn of a hobby servo mounted on the side of the speed controller. The video after the break demonstrates an Arduino driving the servo based on a potentiometer input as well as commands from the CNC controller board he’s using.
Design files for the gears and the Arduino code which drives the servo is available from his Github repository.
Filed under: cnc hacks
Converting an IBM PCjr joystick to USB

Seeing this IBM joystick again really brings back memories. But it can be used on a modern system thanks to this USB conversion project.
This particular model had a connector which is foreign to us. It looks like a boxy USB-A plug, but has an eight-pin sockets which looks like it’s 0.1″ pitch. You could try to make your own male connector using a dual-row pin header, but [Gruso] just went ahead and lopped off the end of the cable. He managed to dig up the pin-out for the device and found that it could be wired up to a gameport — the connector being the only real difference. He gutted a USB gameport adapter, removing the DB15 connector and soldering directly to the board. The boxy old peripheral has just enough room to house that PCB.
If you’re looking for a few more details than this build album provides check out [Gruso's] comments in the Reddit thread.
Filed under: peripherals hacks
Help Hackaday build a custom gaming controller for a good cause
We are going to make a custom gaming controller for a child with Muscular Dystrophy. His name is Thomas and he loves minecraft. This is a project that I have been wanting to do for years. I’m just beginning now, and you can join in on the project and offer your thoughts in our forums. We’re starting with Thomas, but ultimately, we’d like to develop a collection of fairly simple to construct open source game controllers.
For people who have a physical disability, gaming can have a profound psychological impact. Sometimes it is the only place where they can go and be on a level playing ground with their peers. Often custom gaming controllers are quite expensive, especially when you start to leave the standard xbox/playstation form factor.
Now, with 3d printer in hand, I’m able to kick out prototypes much faster and easier than I had ever imagined. I can design something in a matter of minutes, then print it out to see how it feels. Once I get something nailed down, I can refine the design to be easier to assemble, and to fit stock parts you could harvest from an xbox controller (they have an official windows driver, which is nice).
Here’s a quick video of me playing with a prototype idea. You can see I start by laying out all the standard game inputs from the controller, then I toss a slab of imaginary plastic on there and start sculpting. You would want to put velcro on the bottom of this so it would stay in place on a lap board at the perfect comfortable angle.
This is, in no way, a finished prototype. It was just a quick sculpt to get my idea down. Though I only constructed one half of the controller, you can imagine how easily you could position two units like this so that your hands could rest on top of them.
Join in on the forums and help me come up with some more designs that might help!
Filed under: 3d Printer hacks, Featured, lifehacks, Medical hacks
Giant resistor-shaped Ohmmeter

The fun of having a giant resistor-shaped Ohmmeter is that it reads back the resistance by displaying the color code. If you’re not too hot with decoding those bands there’s a helper band to the right which will display the value numerically.
All of the electronics are housed in the opaque part of the resistor, making for a nice low-profile base. The bent leads are hollow and allow [Sebastian] and his friend to run power and measurement leads through to the power connector on the back and the pair of banana jacks near the front. Each translucent ring houses an RGB LED, except for the one on the right which has four 7-segment display modules embedded in it. An ATmega168 takes the measurements using its Analog to Digital Converter (ADC) to read the value from a voltage divider. You can see a quick demo of the Ohmmeter in the video after the jump.
This would be a fun thing to pair with that giant breadboard.
Filed under: Microcontrollers
Hackerspace intro: Metrix Create:Space in Seattle, Washington

Instead of a video, the members of Metrix Create:Space in Seattle, Washington posted a self-guided virtual tour. There is a link to a professional photographer in the area that specializes in this kind of thing. We assume he’s a member and would love to know if he hacked his own setup to capture the spherical panoramas.
The image above looks toward the front entrance. To the right is a cafe type counter which even offers a menu board listing membership prices but also time rentals on things like one hour in the solder room. The tour includes shots from 11 vantage points highlighting each portion of the space. This includes everything you might expect (3d printing, laser cutting, electronic prototyping) but a few you don’t. There’s a toddler-safe play area (we hear that the Kansas City hackerspace has one of these too), and a huge pick and place machine.
Filed under: Hackerspaces
University research dollars poured into developing a Holodeck

It may seem like this would be an early April Fool’s joke, but the image above shows serious research in action. [Ben Lang] recently had the chance to interview the director of a program that wants to make the Holodeck a reality. The core goal of the research — called Project Holodeck — is to develop an affordable multi-player virtual reality experience outside of the laboratory. We’ve heard speculation that Sony and Microsoft will release their next-gen systems in 2013; we’d rather wait for this to hit the market.
[Nathan Burba] is the director of the program. It’s part of the University of Southern California Games Institute and brings together students of Interactive Media, Cinema Arts, and Engineering. The hardware worn by each player is shown off at the beginning of the video after the break. Most of the components are commercially available (a Lenovo laptop worn in the backpack, PlayStation controllers, etc.) but the stereoscopic display which gives each eye its own 90-degree view was developed specifically for the project.
After seeing the in-game rendered footage we can’t help but think of playing some Minecraft with this equipment. We just need some type of omni-directional treadmill because our living room floor space is very limited.
Filed under: Virtual Reality
[Limor] from Adafruit to hang out with President [Obama]
In a positive twist on the usual publicity events that our administration has experimented with over the years, President [Obama] will be hosting a google+ hangout with some lucky people to discuss, well, whatever matters. It is nice to see the people running the country finally getting to grips with some technology. It is still scary to hear how many people making the laws about data still don’t even use a computer.
[Limor] from Adafruit was selected as one of the few that would get to ask the President some questions. She will be focusing on manufacturing and small businesses. We think she’s a great candidate to do so. We’ve watched her go from someone who just did some really well documented hacks to someone who runs a successful business focusing on open information and education (and gadgets of course). You can also submit your own questions, and if they get enough votes, the president will answer them.
Filed under: news
Build an eye tracking headset for $90

Eye tracking is a really cool technology used in dozens of fields ranging from linguistics, human-computer interaction, and marketing. With a proper eye tracking setup, it’s possible for a web developer to see if their changes to the layout are effective, to measure how fast someone reads a page of text, and even diagnose medical disorders. Eye tracking setups haven’t been cheap, though, at least until now. Pupil is a serious, research-quality eye tracking headset designed by [Moritz] and [William] for their thesis at MIT.
The basic idea behind Pupil is to put one digital camera facing the user’s eye while another camera looks out on the world. After calibrating the included software, the headset looks at the user’s pupil to determine where they’re actually looking.
The hardware isn’t specialized at all – just a pair of $20 USB webcams, a LED, an infrared filter made from exposed 35mm film negatives, and a 3D printed headset conveniently for sale at Shapeways.
The software for Pupil is based on OpenCV and OpenGL and is available for Mac and Linux. Calibration is easy, as seen in the videos after the break, and the results are amazing for an eye tracking headset thrown together for under $100.
Filed under: digital cameras hacks
Automatic, custom Eagle schematics

It’s a simple fact that for every circuit you design, someone else has done it before. If you’re working on a high altitude balloon project, there’s already a project out there with a microcontroller, barometric pressure sensor, and an SD card somewhere out there in a corner of the Internet. Google will only help so much if you want to copy these previous builds, which led [Ben] to come up with a better solution. He took dozens of building blocks for basic digital projects and put them all into one really great interface called HackEDA.
The premise is simple: most electronic projects are just electronic Lego. You connect your microcontroller to a sensor, add in a battery, throw in a few caps and resistors for good measure, and hopefully everything will work. HackEDA takes all those basic building blocks – microcontrollers, power sources, and sensors – and creates a custom Eagle schematic with all the parts your project needs
HackEDA is still very much in beta, so there aren’t a whole lot of building blocks to choose from. That said, being able to generate an Eagle schematic with all the parts necessary for your next project is a boon. With this, all you need for a final circuit board is to create a new board file, hit the autorouter, and spend a half hour fixing whatever mess the autorouter made.
Filed under: software hacks
The Firecracker Crossbow
If there are two things that we love at [HAD], giant German firecrackers, and medieval weapons would have to be close to the top of this list. This clever hack gives us both, with a toy crossbow capable of both lighting and launching firecrackers to a safe distance. We didn’t see a blooper reel, but being ready to run in case of a malfunction is probably a good idea as well.
The post has some pictures of the mechanism, but at its heart, this hack consists of ripping up a grill igniter, and placing the contacts into a shortened-stock toy crossbow. Safety is of course encouraged, as much as it can be with this type of device. It’s especially important here as apparently “firecracker” roughly translates in German to “small sticks of high-explosive,” or possibly “road flare.”
Be sure to check out this modded crossbow in action in the video after the break!
Filed under: toy hacks, weapons hacks
Hands on with the super tiny arudino: FemtoDuino
We originally heard about the FemtoDuino last year. It looked good enough and tiny enough, but we didn’t really have a need for it. Recently though, we started on a new project (which you can follow on the forums!) which required an easy modification to an existing circuit. Space and weight were quite important so we decided to pick up a couple femtoduinos at $25 each, and give them a try.
These things are tiny. Their foot print is 20.7×15.2mm. You can see in the picture below, with a quarter for reference. Tiny. Frankly, there’s not much to say about them. They’re an Atmega328 that is arduino compatible. I plan on using my redbull Arduino to program this thing, since you need to bring your own serial interface.

If you’re anything like me, you have atrociously sloppy soldering and shaky shaky hands. I was a bit concerned about actually getting those wires soldered in without bridging the pads. I was able to pull it off though. Here’s a video so you can see how horrible my soldering technique and equipment are.
I really don’t have any complaints about this thing, it works just like an arduino but smaller. The closest thing to a complaint is that the silk screening is a bit blurry making it difficult to read which pins are what. It isn’t horrible, but it isn’t perfect either. We really couldn’t think of much else so we decided a haiku would cover it.
one arduino
much smaller than a quarter
Femtoduino
Of course, if you want to follow along and see if I end up with complaints, you can watch me build these battling star wars themed R/C cars.
Filed under: arduino hacks, reviews
Cracking a SAM7XC cryptographic coprocessor

[Adam Laurie] spent time tearing into the security of the SAM7XC chip produced by Atmel. Even if he hadn’t found some glaring security holes just reading about his methodology is worth it.
The chip is used in a secure RFID system. The chip is added to the mix to do the heavy lifting required when using encryption. [Adam] grabbed a couple of open source libraries to put it to the test. The firmware is locked down pretty tight, but his explorations into the content of the RAM yield a treasure trove of bits. After investigating the sample code for the chip he’s shocked to learn that it uses RAM to store the keys at one point. The rest of his journey has him dumping the data and sifting through it until he gets to the “Master Diversification Key”. That’s the big daddy which will let him decrypt any of the tags used.
He reported his findings to Atmel in September of 2011. Their response is that they have no way of protecting RAM from exploit. [Adam] asserts that the problem is that the sample software wasn’t designed with the vulnerability of RAM in mind. The keys should never be stored there specifically because it is vulnerable to being dumped from a running system.
Filed under: security hacks
Automatic volume control puts the kibosh on loud TV commercials

If you’re having a hard time tuning out those loud commercials why not let your electronics project do it for you? This is an Arduino-based setup which adjusts television volume when it goes above a certain threshold. It uses a microphone, rather than a direct audio signal, so you can set it based on what is actually heard in the room.
The control scheme uses the IR LED and IR receiver seen on the breadboarded circuit above. The receiver lets you teach your volume up and down buttons from your remote control to the system. The one failing we see in the design is that the volume level is hard-coded, requiring you to flash new code to make adjustments (perhaps an enterprising reader could add a potentiometer for making easy adjustments?).
We can’t help but be reminded of the setup which reads the closed caption info to mute topics you’ve added to a blacklist.
Filed under: arduino hacks, home entertainment hacks
Script lets you import Eagle boards for use in FreeCAD

[Christian Aurich] wanted to use his Eagle CAD circuit board design in a proper CAD program in order to design enclosures. There are already a few options along these lines, but they didn’t quite fit his needs so he developed a script to import Eagle boards into FreeCAD. The script is packaged as a python macro for FreeCAD.
In describing the shortcomings of what’s already out there [Christian] does mention the use of EagleUp to model boards in Google SketchUp. But he feels the way the data is produced by SketchUp makes these models work well with 3D printing, but says they’re not easy to use with mechanical design CAD software. He also feels that the photo-realistic renderings are useless when developing enclosures.
It’s worth mentioning that this approach is only possible because CadSoft’s migration to XML makes it dead simple to get at the data.
Filed under: cnc hacks
Digging deeper into the Apollo Saturn V LVDC

[Fran] went all-out with her reverse engineering of the Apollo Saturn V LVDC board. Regular readers will remember that she was showing of the relic early this year when she took the board to her Dentist’s office to X-ray the circuit design. Since then she’s been hard at work trying to figure out how the thing functions using that look inside the board and components. When we say ‘hard at work’ we really mean it. Not only did she explore many different theories that resulted in dead ends, she also built her own version of the circuits to make sure they performed as she theorized. Above you can see her version of the NAND/AND gates used on the hardware.
We find her explanation of how the logic devices were originally fabricated to be very interesting. They started with a ceramic substrate and used additive processes to form the traces and add the gates. We’ve embedded her video explanation after the jump.
Filed under: Microcontrollers
GLCD clock project packed with great UI and features

This Graphic LCD clock doesn’t have a fancy case, but [Gregory Wright] built in so many great features we think it will serve as inspiration for many projects to come. If he does decide to add a case it will be quite easy as there are no buttons to work around.
Without buttons how can the thing be adjusted? He decided to go with an IR remote control for all settings. This gives him a lot more options than a handful of buttons would have. Plus, heavy sleepers will need to find the remote control in order to shut off the alarm. We also think it’s interesting that the 595 shift registers he used have a low enough data high threshold (3.15V when VCC is 4.5V) that he didn’t need level converters to drive the 5V display with his 3.3V MSP430 Launchpad.
Check out his video after the break to learn about all the features he included in the UI. Our favorite is shown on the bottom right where it says “Hello World”. This is an area dedicated to a custom message for each day. He uses it to remind him about trash day (now there’s a feature!).
Filed under: clock hacks
Harry Potter location clock spies on your smart phone

The location clock found in the Harry Potter books makes for a really fun hack. Of course there’s no magic involved, just a set of hardware to monitor your phone’s GPS and a clock face to display it.
[Alastair Barber] finished building the clock at the end of last year as a Christmas gift. The display seen above uses an old mantelpiece clock to give it a finished look. He replace the clock face with a print out of the various locations known to the system and added a servo motor to drive the single hand. His hardware choices were based on what he already had on hand and what could be acquired cheaply. The an all-in-one package combines a Raspberry Pi board with a USB broadband modem to ensure that it has a persistent network connection (we’ve seen this done using WiFi in the past). The RPi checks a cellphone’s GPS data, compares it to a list of common places, then pushes commands to the Arduino which controls the clock hand’s servo motor. It’s a roundabout way of doing things but we imagine everything will get reused when the novelty of the gift wears off.
Filed under: gps hacks
Minecraft for RPi Released
Mojang, the folks behind Minecraft, have officially released Minecraft: Pi Edition. This free version of the popular game is optimized to run on the Raspberry Pi hardware, and has an API that exposes the game’s internals to a variety of programming languages.
Mojang intends this release to be an educational tool for teaching and learning programming. Since the API provides instant feedback in the game, it could be an interesting way to make learning to code fun for people of all ages.
Having access to the API on a RPi also means that the game can be connected to the real world. For example, using Python and the RPi.GPIO, pins on the GPIO header can be used for output or input. This creates a slew of possible hacks that interface with the game.
Any ideas on what you’d like to do with Minecraft on a RPi? Let us know in the comments. Also, we coincidentally just printed a minecraft axe on our 3d printer. There’s a time lapse video of it after the break!
Filed under: Raspberry Pi






