Hackaday Prize Entry: Economical Bionic Leg

October 6, 2017 by 9 Comments

When it comes to high-tech bionic legs for amputees, all the cool stuff is titanium, carbon fiber or other, more exotic materials. With carbon fiber “blades” all the rage, it’s easy to forget that simpler technologies still work, and could be made to work even better with the addition of some inexpensive electronics. The Economical Bionic Leg project is the result of that idea.

Project creators [PremJ20] and [G.Vignesh] aren’t kidding about bringing the cost of these bionic legs down. The target goal is $60 per, with stainless steel and silicon rubber as a cheaper alternative to carbon fiber — the rubber would be molded to fit the amputated region. The heart of the project is a Particle Photon development board, with a flex sensor and accelerometer monitoring the prosthesis and supplying data to the cloud. It’s essentially a basic prosthetic leg with a monitoring system built in. Placing a sensor cuff on the regular leg, the artificial limb’s flexibility can be fine-tuned to match the two.

Will this inexpensive bionic leg ever compete in the Olympics, like [Oscar Pistorious] run in the 2012 London event? Probably not — the tech that goes into artificial limbs has the same amount of material science going into it as F1 racing and turbojet design. Still, this is a very cheap way to bring tech into something that desperately needs to be cheaper, and it’s a great Hackaday Prize entry, to boot.

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Retrotechtacular: Hacking Wartime Mail

October 6, 2017 by 33 Comments

I’m guessing you got quite a few e-mails today. But have you ever had a v-mail? That sounds like some new term for video e-mail, but it actually dates back to World War II. If you are in Europe, the term was Airgraph — not much more descriptive.

If you make a study of war, you’ll find one thing. Over the long term, the winning side is almost always the side that can keep their troops supplied. Many historians think World War II was not won by weapons but won by manufacturing capability. That might not be totally true, but supplies are critical to a combat force. Other factors like tactics, doctrine, training, and sheer will come into play as well.

On the other hand, morale on the front line and the home front is important, too. Few things boost morale as much as a positive letter from home. But there’s a problem.

While today’s warfighter might have access to a variety of options to communicate with those back home, in World War II, communications typically meant written letters. The problem is ships going from the United States to Europe needed to be full of materials and soldiers, not mailbags. With almost two million U.S. soldiers in the European Theater of Operations, handling mail from home was a major concern.

British Mail Hack

The British already figured out the mail problem in the 1930s. Eastman Kodak and Imperial Airways (which would later become British Airways) developed the Airgraph system to save weight on mail-carrying aircraft.  Airgraph allowed people to write soldiers on a special form. The form was microfilmed and sent to the field. On the receiving end, the microfilm was printed and delivered as regular mail.

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“The Cow Jumped Over The Moon”

October 6, 2017 by 12 Comments

[Ash] built Moo-Bot, a robot cow scarecrow to enter the competition at a local scarecrow festival. We’re not sure if Moo-bot will win the competition, but it sure is a winning hack for us. [Ash]’s blog is peppered with delightful prose and tons of pictures, making this an easy to build project for anyone with access to basic carpentry and electronics tools. One of the festival’s theme was “Out of this World” for space and sci-fi scarecrows. When [Ash] heard his 3-year old son sing “hey diddle diddle, the cat and the fiddle…”, he immediately thought of building a cow jumping over the moon scarecrow. And since he had not seen any interactive scarecrows at earlier festivals, he decided to give his jumping cow a lively character.

Construction of the Moo-Bot is broken up in to three parts. The skeleton is built from lumber slabs and planks. The insides are then gutted with all of the electronics. Finally, the whole cow is skinned using sheet metal and finished off with greebles to add detailing such as ears, legs, spots and nostrils. And since it is installed in the open, its skin also doubles up to help Moo-bot stay dry on the insides when it rains. To make Moo-Bot easy to transport from barn to launchpad, it’s broken up in to three modules — the body, the head and the mounting post with the moon.

Moo-Bot has an Arduino brain which wakes up when the push button on its mouth is pressed. Its two OLED screen eyes open up, and the MP3 player sends bovine sounding audio clips to a large sound box. The Arduino also triggers some lights around the Moon. Juice for running the whole show comes from a bank of eight, large type “D” cells wired to provide 6 V — enough to keep Moo-Bot fed for at least a couple of months.

Check out the video after the break to hear Moo-bot tell some cow jokes – it’s pretty funny. We’re rooting for it to win the competition — Go Moo-bot.

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BOM Cost Optimization And Tindie Badge Engineering

October 6, 2017 by 16 Comments

For the last few months, I’ve been up to my neck in electronic conference badges. This year, I created the single most desirable badge at DEF CON. I also built a few Tindie badges, and right now I’m working on the logistics behind the Hackaday SuperConference badge. Sit tight on that last one — we’re doing something really, really special next month.

Most badge projects are one-off production runs. This is to be expected from a piece of hardware that’s only meant to be distributed at a single event. The Tindie badge is different. It’s now a thing, and we’re building multiple badges for all the cons and conferences Hackaday and Tindie are attending for the rest of the year. This means I have the opportunity to do hardware revisions on the Tindie badge. Right now I’ve built three versions of the Tindie and we’ve distributed about two thousand of these kits at DEF CON, Maker Faire New York, and the Open Hardware Summit.

After about two thousand units, I think we finally have this down. This is how I designed three versions of hardware in as many months and cut the BOM cost of each badge in half. This is bordering on a marginally impressive piece of engineering, and a great lesson on BOM cost optimization.

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Running The SNES Classic Mini Emulator On The Raspberry Pi

October 6, 2017 by 30 Comments

Unless you’ve been living under a rock, you’d be familiar with Nintendo’s hugely popular Classic Mini consoles. Starting with the NES, and now followed with the SNES, the consoles ship in a cute, miniature enclosure and emulate Nintendo classics using the horsepower of modern ARM chips. These consoles use an emulator that has been created especially for the purpose by Nintendo, in house – and [Morris] [krom] wanted to see if he could take the emulator on the SNES Classic Mini and run it on the Raspberry Pi.

Yes, there are already SNES emulators on the Raspberry Pi. But anyone interested in the nuts and bolts of emulation can see the clear interest in the tricks and techniques Nintendo are using to achieve the feat. In particular, Nintendo engineers have the benefit of access to internal documentation that can make the job a lot easier, particularly when dealing with edge cases.

[krom] has been kind enough to share the full instructions necessary to recreate this feat. One stumbling block was the difference in hardware between the Raspberry Pi and the SNES Classic Mini – the Pi using a Broadcom GPU instead of the SNES’s Mali hardware. However, a workaround was simple enough – swapping out some libraries was all that was required. It also gives some interesting insight – it looks like the SNES Classic Mini relies on the SDL libraries to run.

While emulation of the SNES has been a largely solved problem for quite some time, it’s great to see more work going on in the field. In particular, the official Nintendo emulation is reported to be particularly adept at running games that rely on the SuperFX chip.

For another take on SNES emulation, try out your old Mario games on the HoloLens.

Thanks [Morris] for the tip!

Engineering And Artistry Meet An Untimely End At Burning Man

October 6, 2017 by 38 Comments

Burning Man is so many different things to so many people, that it defies neat description. For those who attend, it always seems to be a life-changing experience, for good or for ill. The story of one man’s Burning Man exhibition is a lesson in true craftsmanship and mind-boggling engineering, as well as how some events can bring out the worst in people.

For [Malcolm Tibbets], aka [the tahoeturner], Burning Man 2017 was a new experience. Having visited last year’s desert saturnalia to see his son [Andy]’s exhibition, the studio artist decided to undertake a massive display in his medium of choice — segmented woodturning. Not content to display a bamboo Death Star, [Malcolm] went big– really big. He cut and glued 31,000 pieces of redwood into rings of various shapes and sizes and built sculptures of amazing complexity, including endless tubes that knot and loop around and back into each other. Many of the sculpture were suspended from a huge steel tripod fabricated by [Andy], forming an interactive mobile and kinetic sculpture.

Alas, Burning Man isn’t all mellowness in the desert. People tried to climb the tripod, and overnight someone destroyed some of the bigger elements of the installation. [Malcolm] made a follow-up video about the vandalism, but you’ll want to watch the build video below first to truly appreciate the scale of the piece and the loss. Here’s hoping that [Malcolm]’s next display is treated with a little more respect, like this interactive oasis from BM 2016 apparently was.

Thanks to [Keith Olson] for the tip.

The Cambridge Z88 Lives! (As A USB Keyboard)

October 5, 2017 by 19 Comments

What did [Clive Sinclair] do next? After his line of home computers including the iconic ZX Spectrum hit the buffers and was sold to Amstrad, that is. No longer in the home computer business, he released a portable computer for the business market. The Cambridge Z88 had a Z80 at its heart, a decent keyboard, a text-only LCD display, and ran for an impressively long time on a set of AA alkaline cells. It made a handy portable word-processor, or a serial terminal thanks to its rare-for-the-time RS232 port. And it’s that port that [Spencer Owen] made use of his Z88 in a modern setting, using it as a USB keyboard.

It’s a few years old, so he used a Minimus AVR microcontroller board to provide a serial-to-USB HID keyboard interface, and to keep things tidy he’s made a poor man’s enclosure for it using Sugru. It’s not quite an amazing hardware hack, but we’re featuring it simply for its use of a Z88. Retro computers used as keyboards are a common theme, but a Z88 is a particularly eclectic choice.

If you’re not British you may only know the name [Sinclair] through Brits on the Internet waxing lyrical about their ZX Spectrum computers, but in fact the man behind them is a serial electronics entrepreneur whose career has continued since the 1960s and has touched fields as diverse as portable television and bicycles aside from the computers he is best known for. Often his products took technology to the limit of practicality, but they were and continue to be the ones to watch. If [Clive Sinclair] is working in a field his products may not always hit the right note when released, but you can guarantee that you’ll be buying the same thing from the big boys within a few years. The Z88 is a classic Sinclair product, a little before its time in 1988 and pushing the technology a little too far, but delivering a truly portable and capable computer with a meaningful battery life a couple of decades before you’d find the same attributes from all but a few other niche manufacturers.

Not had enough USB HID devices? How about a Morse key? And if [Spencer] rings a bell, he’s the originator of the RC2014 retrocomputer we reviewed last year.