In GPS technology, the phrasing “COCOM Limits” is also used to refer to a limit placed to GPS tracking devices that should disable tracking when the device realizes itself to be moving faster than 1,000 knots (1,900 km/h; 1,200 mph) at an altitude higher than 60,000 feet (18,000 m). This was intended to avoid the use of GPS in intercontinental ballistic missile-like applications. Some manufacturers apply this limit literally (disable when both limits are reached), other manufacturers disable tracking when a single limit is reached.
Somewhat of a problem for homemade space programs?
A potato powered transistor oscillator with light dependent resistor, which gets its power from potato battery. Low power circuit is based off Forrest Mims light-dependent oscillator.
an experimental art project that explores sounds and visuals through DIY electronics, circuit bending, and self-made instruments; utilizing electronic salvage and reclaimed materials as a platform for audio-video expedition.
They start ‘em young in Detroit. Here’s “hackerbaby” Aiden at i3 Detroit, armed and adorable, and ready for this weekend’s Maker Faire Detroit. Go, Aiden!
Perfect eavesdropping on a quantum cryptography system – The stated goal of quantum key distribution (QKD) is to grow a secret key securely between two parties with a minimum of additional assumptions. The number of assumptions has been continuously reduced, from requiring the validity of quantum mechanics in early QKD, to more general constraints on the laws of physics in device-independent QKD. Despite steady theoretical progress in dealing with known limitations of current technology, in practice the security of QKD relies not only on the quantum protocol but on the physical implementation. A variety of attacks have been conceived to exploit weaknesses of current systems. Here we demonstrate the first full field implementation of an eavesdropper attacking an established QKD connection. The eavesdropper obtains the complete ‘secret’ key, while none of the results measured by the legitimate parties indicate a breach in security. This confirms that non-idealities in physical implementations of QKD can be fully exploitable.
More and more books keep being released about our favorite little microcontroller, the Arduino. Apress offers a new one tomorrow entitled Arduino Robotics. Written by Josh Adams, John-David Warren, and Harald Molle, it’s a monster 628 pages and will teach you, according to the book’s description, how to use your Arduino to control a variety of different robots, while providing step-by-step instructions on the entire robot building process. You’ll learn Arduino basics as well as the characteristics of different types of motors found in robotics. You also discover controller and failsafe methods, and learn how to apply them to your project. The book starts with basic bots and moves into more complex projects, including a GPS-enabled robot, a robotic lawnmower, a fighting robot, and even a DIY Segway-clone.
Some of you are likely familiar with co-author JD Warren. He’s the creator of the RC lawnmower on the cover of MAKE Volume 22. I also interviewed JD and co-author Josh in The Latest in Arduino Episode 2.
I’ll be reviewing this new book in more detail in next month’s The Latest In Arduino Episode 3. From my early scan of the book, I think you’re going to be very happy with the level of detail provided, and I’ll be sure to offer specific examples. So stay tuned.
Automate your world with remote control. From pet care to power outlets, from toys to telepresence, we’ll show you how to add a joystick, push-button, twist-knob, or timer to just about anything.
In the future, credit card fulfillment hangs from a lanyard. Vendors at Maker Faire.
The folks over at Intuit are offering this deal to makers and crafters selling at Maker Faire Detroit. If you accept credit card transactions on Visa, MasterCard, and Discover cards, on July 30th and 31st, using your mobile phone or tablet and Intuit GoPayment, it’s free during the Faire. No transaction fees! They’ll even give you a GoPayment card swiper that attaches to your mobile device.
Here are the full details:
1. Before Maker Faire, visit this page. To take advantage, you must sign up on this special Maker Faire page!
2. A list of GoPayment compatible phones and tablets is available on the site. Be sure to check and see if your mobile device is listed.
3. Click “Give it a Try” to complete the GoPayment application. You’ll be approved in a matter of seconds and will get an email from Intuit with instructions for getting started.
4. Download the free GoPayment App from the Apple App Store, Android Market, or Blackberry App World.
5. You should receive the free GoPayment swiper in the mail. If you don’t receive it before Maker Faire, no worries, there will be one waiting for you on registration day.
When we say free, we mean free. This special offer comes without a commitment and no additional monthly or annual fees will kick in after the weekend. Give us a try and if you happen to love GoPayment you can keep using it post-Maker Faire and only pay-per-use at our standard rates. Email GoPayment_Help@intuit.com for more info or reach out to us on Facebook.
We’re looking forward to Maker Faire Detroit and hope to help you make the most of this great event!
The printable ball-and-socket unit that makes up this tentacle is really just a prototype in the early development of Thingiverse user Misguided’s not-so-misguided (IMHO) project to develop a printable tentacle arm. Everything about his description makes me happy, so I’ll just quote it entirely:
I’m trying to make a mind controlled tentacle and this is where I’m at so far.
Right now, the ball and socket joints are a little too loose, and the movement isn’t very good (partly due to the weight of the parts).
Also the sockets are a little stiff and fragile when printed with PLA.
Once all that is sorted, I’ll hook it up to some servos and the obligatory Arduino.
Ben Delarre shared his story with Make about the origins and future of Circuitbee, a service that allows you to embed schematics on websites.
Have you ever designed an electronic schematic then wanted to share it on your blog? Or wanted help improving your circuit on a forum? Ever peered at a tiny/massive image of a circuit on a website and wondered why on earth there wasn’t a better alternative?
We have. Back in 2010 we were working on our first major electronics project, the Illuminatrix, an array of 256 RGB LEDs that were to show animations created by people all over the world at the Burning Man festival. It involved using a lot of technology we’d never used before, so we weren’t quite sure about our circuit designs.
We tried posting on blogs and forums trying to explain our schematic and the problems we were having with it. This proved more difficult than we expected: describing a circuit in words is really hard, so we tried to post an image of our schematic instead, and our schematic project files.
This involved a lot of messing around with capturing JPEGs of the schematic and uploading all the project’s symbol libraries and schematic files. But of course people willing to help didn’t necessarily have the right software, or the JPEG was too small to read usefully, or too large to post on many of the forums. We thought that there must be a better way to share schematics, to discuss them, and to show them to people while writing about them. It turned out there wasn’t anything out there that would help us do this, so being the ambitious fools that we are we set out to create it.
CircuitBee is like YouTube for your circuit schematics. You upload your Eagle or KiCAD schematics, we crunch the numbers and create an online embeddable version of your schematic. You can pan and zoom, and mouse over components in your circuits for more details .
We’re still at an early alpha stage right now, so you’ll have to forgive any hiccups we have going forward. But you can get started immediately by visiting Circuitbee and signing up for an account. Then simply upload your schematic files, any associated library files, and let our servers do the hard work. Within a few minutes your schematic should be ready to embed on your site or forum.
Eventually we plan to add lots more useful features like downloading original schematic files, searching for components within schematics and adding notes and annotations to your circuits. We want to make it easier for all of us to communicate our circuit design ideas and to help each other improve our designs.
We hope to make CircuitBee into the most useful service for hobby electronics enthusiasts, so we’re going to keep the service free for as long as we can. We’ll need your help to reach our goals though, so please let us know what you think of the site, what needs improving and what else we can do to make learning about electronics and sharing your designs easier than ever before.
If you want to make a screw of wood, the first tool you would think baout is a lathe. But you can also make a screw on a scroll saw. In fact, I was stunned to learn of a surprising technique for using a scroll saw to make nested screws from a single cylinder of wood. These four helices were cut by Steve Garrison, who was the first to think of this, as far as I know.
They nest inside of each other beautifully, because they started out that way. Steve’s website explains the technique, which is so simple that anyone can make a basic screw in minutes. Simply tilt the scroll saw table, clamp a piece of wood to the table to serve as a fence, and push a dowel through the blade while twisting it. To make a smooth spiral cut, first mark a spiral on the dowel, to guide you in controlling the twist as you push. Use a “spiral” blade, which has teeth on all sides, because different parts of the rotating wood hit opposite sides of the blade. In general, the top of the blade will trace one spiral on the cylinder’s surface and the bottom of the blade will trace another. What Steve realized is that by varying the table tilt and the distance from the blade to the cylinder’s center line, you have two parameters for adjusting where those two helices lie on the surface. There are multiple combinations of these parameters which make the two surface spirals coincide. In other words, the blade can always come out of the same spiral from which it enters, while cutting in at various depths.
Because these surfaces are cut by a moving line, all the spirals are examples of ruled surfaces and, more specifically, are types of generalized helicoid.
I have found this a great puzzle to hand to a woodworker and ask them how they think is was made.
More:
See all of George Hart’s Math Monday columns
The next episode of our streaming show and tell Make: Live is a special broadcast from Maker Faire Detroit, live from the Henry Ford this Friday. Join us as we celebrate the kickoff of a weekend of making in the Mitten at the worlds largest DIY festival.
Make: Live 13 – Maker Faire Detroit
Friday July 29th, 5:30pm ET/2:30pm PT
Watch at makezine.com/live or on UStream
Please join us in the UStream chat or mark tweets with #makelive to interact live with the show.
We also give away a fabulous prize from Digi-Key to one chat member who can solve our photo challenge.
Clever idea from Japanese firm SoftEther, whose press release is available in English onlyvia machine translation as of this writing. The video pretty much conveys the idea, however. QUMA is rather like an artist’s figure-drawing mannequin with sensors in the joints that report all the articulations through a USB cable. Appropriate software can then position a character’s rigging to match, which seems like it would be both faster and more intuitive than dragging bones around a screen with a mouse.
Niklas Roy has built an addictive-looking 70′s-style videogame system that is “controlerless” like an Xbox Kinect, yet charmingly low-rez like Pong.
What I found interesting when I developed this game, is, that it could have been made already in the seventies. The technology that I used for it is (in a way) similar to what Atari used for the first Pong. It becomes even more awkward, if you think that the electronic components for capturing and evaluating a video signal are cheaper than the rotary game controllers that Atari used.
The game is programed with AVR-GCC on an ATmega8 microcontroller that runs with 16MHz. The controller gets basic videosignal synchronisation information from an LM1881 sync separator that triggers two hardware interrupts. One for a new image, the other one for a new line. The controller evaluates the brightness around the pixel (/ball) via its comparator input. Drawing the white image overlay is realized with a simple pull-up resistor in the signal line.
Niklas has shared the source code here. Now, please give us a schematic, because I want to build one!
