Why Is There Liquid Nitrogen On The Street Corner?

July 21, 2015 by James Hobson 107 Comments

Any NYC hackers may have noticed something a bit odd this summer while taking a walk… Giant tanks of the Liquid Nitrogen have been popping up around the city.

There are hoses that go from the tanks to manholes. They’re releasing the liquid nitrogen somewhere… Are they freezing sewer alligators? Fighting the Teenage Mutant Ninja Turtles? Or perhaps, cooling our phone lines??

Luckily, we now have an answer. Popular Science writer [Rebecca Harrington] got to investigate it as part of her job. As it turns out, the liquid nitrogen is being used to pressurize the cables carrying our precious phone and internet service in NYC. The cables have a protective sheath covering them, but during construction and repairs, the steam build up in some of the sewers can be too much for them — so they use liquid nitrogen expanding into gas to supplement the pressurized cables in order to keep the them dry. As the liquid nitrogen boils away, it expands 175 times which helps keep moisture out of the cables.

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Vintage Electronics Magazines Predicted Our Current Future

July 13, 2015 by Gregory L. Charvat 57 Comments

Do you remember the magazine Popular Electronics? What about Radio Electronics? These magazines were often the first exposure we had to the world of hacking. In December we learned that Americanradiohistory.com has gone to the trouble of scanning nearly every copy of both, and continues to add many many others — posting them online for us to enjoy once more. Since then we’ve been pouring through the archive pulling out some of the best in terms of nostalgia, entertainment, and fascinating engineering.

Yes much of this material is very dated; CB Radios, all-mighty computers, phasors, stun guns, levitating machines, overly complex circuits for simple tasks, and aviator eyeglasses. But found among all of this, many innovative mixed-signal circuits and other interesting ideas that have been developed into our tech-centric world. Many of those modern inventions you’ve welcomed into your life actually started long-long ago in the forward-thinking hacks shown off in these publications. The Google Glass precursor seen above is but one example. Keep reading to see the early roots of the tech we tend to think of as “new”.

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CD Execution Chamber Sends Old Discs Off With A Bang

July 10, 2015 by Dan Maloney 22 Comments

Welded steel safety cage? Check! Polycarbonate blast shield? Check! Vacuum cleaner motor wired to an inviting red button? Double check! Stack of CDs to dispose of as destructively as possible? [Firas Sirriyeh] has got you covered with his CD Terminator 1.0.

While [Firas’s] build log is a little short on descriptive text, there’s really no need for it. His pictures tell the tale. The combination media shredder and interactive performance art piece is a stoutly constructed affair, which you’d want anything capable of flinging razor-sharp plastic and Mylar shrapnel to be. [Firas] has displayed his CD execution chamber at the Jerusalem Mini Maker Fair 2015 (in Hebrew; English link) and the Musara Mix Festival where the must-see video after the break was shot (mildly NSFW language). Some CDs give up the ghost very quickly, but one held out for a remarkable long time before finally exploding; you can see it flexing and warping in a way that almost appears to be slow-motion.

For those who’d rather not fuss with all that bothersome safety, there’s always this automatic CD launcher to play with.

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Shapeshifting Material For Weather Adaptive Structures

July 10, 2015 by Dan Maloney 14 Comments

Where [Isaac Newton] had his apple (maybe), [Chao Chen] found inspiration in a pine cone for a design project that lead to a water-sensitive building material. He noticed the way some pine cones are sensitive to water, closing up tight when it rains, but opening up with dry conditions. Some dissection of a pine cone revealed [Mother Nature’s] solution – different layers that swell preferentially when exposed to moisture, similar to how a bimetallic strip flexes when heated. [Chao Chen’s] solution appears to use balsa wood and a polystyrene sheet laminated to a fabric backing to achieve the same movement – the wood swells when wet and pulls the laminate flat, but curls up when dry.

As [Chao] points out, the material is only a prototype, but it looks like a winner down the road. The possibilities for an adaptive material like this are endless. [Chao] imagines a picnic pavilion with a roof that snaps shut when it rains, and has built a working model. What about window shutters that let air and light in but close up automatically in that sudden summer storm? Self-deploying armor for your next epic Super Soaker battle? Maybe there are more serious applications that would help solve some of the big problems with water management that the world faces.

Make sure you check out the video after the break, with a more decorative application that starts out looking like an [M.C. Escher] print but ends up completely different.

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The Best NiMh Charger?

July 9, 2015 by Nava Whiteford 32 Comments

[Paul Allen] has been working on the latest iteration of his NiMh battery charger and it looks amazing!

We’ve covered [Paul Allen]s awesome hacks and tutorials before, but never this project. What makes his charger so special is it’s ability to monitor and log every aspect of the charging process. Not only does it have a SD card for data logging, but it also interfaces with a Windows application for real-time monitoring as well as analysis and visualization of the charging process (Linux users don’t fret it has a serial interface too).

[Paul] doesn’t say if he plans to open hardware or kickstart the charger, but some of his older posts give us a quick peak at the gerbers. Let’s hope this awesome project makes its way into the wild soon, and hopefully we’ll be able to try it for ourselves and see if it lives up to its name.

Coin-Op Weather

July 8, 2015 by Dan Maloney 1 Comment

When you have access to your own CNC machine, you tend to make stuff first and ask questions later. That sounds like how [Rui Cabral] came up with a weather station stuffed into a miniature arcade game cabinet.

Standing only about 16 cm tall, the cabinet is quite detailed and resembles the familiar arcade form factor that has consumed countless quarters. It even appears to be made of particle board like the big boys. The screen cutout is filled by a 84×48 monochrome Nokia display, and the rest of the cabinet’s interior is stuffed with a CNC-milled PCB, temperature and humidity sensors, an RTC, and a Bluetooth module for uploading data to a phone. [Rui] even manages to work in an homage to the grand-daddy of all arcade games with a Pong splash screen.

Another good-looking display for this project might have been this ePaper badge made into a weather station. And we’ve featured even tinier arcade cabinets too, though perhaps not as functional.

[Rui] takes us on a video tour of his build after the break.

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Micro:bit — BBC Gets A Million Kids Into Embedded Dev

July 7, 2015 by Brian Benchoff 149 Comments

In the Early 1980s, the BBC launched a project to teach computer literacy to a generation of British schoolchildren. This project resulted in the BBC Micro, a very capable home computer that showed a generation exactly what a computer could do. These children then went home, turned on their ZX Spectrums, and became a generation of software engineers. Still, the BBC Micro is remembered fondly.

The computer revolution is long over, but today we suffer a sea change of embedded processors and microcontrollers. With Arduinos and Raspberry Pis, the BBC has decided it’s time to put the power of an ARM microcontroller into the hands of a million 11- and 12-year olds. The result is the Micro:bit. It’s a small microcontroller board with an ARM processor, an IMU, buttons, Bluetooth and a 5×5 LED array – exactly what you need if you’re teaching a million kids how to blink an LED.

Although the BBC has finalized the design for the Micro:bit, there are no specs at all. However, a few educated guesses can be made. The USB controller is provided by Freescale, who also provide the digital compass and magnetometer. Programming is done through a web-based, Arduino-like IDE with what appears to be a decent Micro:bit specific library. The board is also mbed compatible. Bluetooth, and apparently the ARM Cortex M0 core, is provided by a Nordic nRF51822. There are only three alligator clip-compatible I/Os, and its doubtful any student will be building anything that would be too complex for an entry level ARM. It’s also 3V logic; finally, the tyranny of 5V has fallen.

The Micro:bit is best seen as a tool that enables the relatively recent addition of a computer science curriculum in UK schools. There is now a requirement for seven-year-olds to understand algorithms and create simple programs. Previously computer education in the UK has consisted of PowerPoint. Now, secondary school students will be learning Boolean logic.

While the Micro:bit is utterly useless as a tool for doing real work, education is not real work. For blinking a few LEDs, having a device react to movement, playing with Bluetooth, and other lesser evils of electronics, the Micro:bit is great. Not everyone will become the digital technologists this initiative is trying to create, but for those who have an inclination towards semicolons and electrons, this is a great introduction to technology.