Tubular Tape Gun “Sketches” Furniture You Can Never Sit On

October 29, 2015 by 37 Comments

Sometimes you just need a life-sized model. When you do, reach for your (highly modified) tape gun and get drawing.

As the Protopiper team describes it, the “gun” is a computer-aided hand held fabrication device for imagining layouts of large objects — the main example they give is furniture. Want to make sure that couch will fit? Why not spend 10 minutes building a tape model of it?

Sound crazy? Kind of, but the device itself is rather ingenious. It takes normal tape, measures it, and rolls it into tube form, which results in a surprisingly strong structure allowing you to build 3D shapes quite easily. From a design point of view it’s quite brilliant.

From the mechanism that rolls the tape into a structural tube to the winged end-connectors that allow you to easily attach to another tube or structure, the whole thing must have gone through many design iterations to get right. We’re impressed.

Alternatively for printing extremely large shapes, why not build a building sized delta-bot?

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Embed With Elliot: Going ‘Round With Circular Buffers

October 29, 2015 by 51 Comments

Why Buffer? Because buffers cut you some slack.

Inevitably, in our recent series on microcontroller interrupts, the question of how to deal with actual serial data came up. In those examples, we were passing one byte at a time between the interrupt service routine (ISR) and the main body of code. That works great as long as the main routine can handle the incoming data in time but, as many people noted in the comments, if the main routine takes too long the single byte can get overwritten by a new one.

The solution? Make some storage room for multiple bytes so that they can stack up until you have time to process them. And if you couple this storage space with some simple rules for reading and writing, you’ve got yourself a buffer.

So read on to see how to implement a simple, straightforward circular buffer in C for microcontrollers (or heck, for anything). Buffers are such a handy tool to have in your programming toolkit that you owe it to yourself to get familiar with them if you’re not already.

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Even If I Could Take Off, I Could Never Get Past The Tractor Beam!

October 29, 2015 by 25 Comments

Finally our childhood dreams of a working tractor beam are coming to fruition! It’s called acoustic levitation and it actually uses highly concentrated sound waves to float small objects by essentially creating an acoustic force field.

The concept is nothing new, in fact we first covered it back in 2014 — but since then they’ve made leaps and bounds in their research. Back then they could just levitate dust. Now we’re moving onto small objects, like googly-eyes! It’s perceivable that with powerful enough speakers, larger objects will soon be harnessed…

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Secret Radio Stations By The Numbers

October 29, 2015 by 124 Comments

One thing has stayed with the James Bond movie franchise through the decades: Mr. Bond always has the most wonderful of gadgets. Be it handheld, car-based, or otherwise, there’s always something to thrill that is mostly believable.

The biggest problem with all of those gadgets is that they mark Commander Bond as an obvious spy. “So Mr. Bond, I see you have a book with many random five character groups. Nothing suspicious about that at all!” And we all know that import/export specialists often carry exploding cufflinks or briefcases full of unknown electronics in hidden compartments.

Just as steganography hides data in plain sight, the best spy gadgets are the ones that don’t seem to be a spy gadget. It is no wonder some old weapons are little more than sticks or farm implements. You can tell a peasant he can’t have a sword, but it is hard to ban sticks.

Imagine you were a cold war era spy living in a hostile country with a cover job with Universal Exports. Would you rather get caught with a sophisticated encryption machine or an ordinary consumer radio? I’m guessing you went with the radio. You aren’t the only one. That was one of the presumed purposes to the mysterious shortwave broadcasts known as number stations. These were very common during the cold war, but there are still a few of them operating.
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3D Printed Helix Displays Graphics In 3D

October 29, 2015 by 39 Comments

It looks like [Michel David] and his team at volumetrics.co have really upped their game: the game being production of a 3D volumetric video display.

We’ve covered an earlier version of the same technique, and still the best technical explanation of what they’re up to is to be found at their old website. But it’s a simple enough idea, and we expect that all of the difficulty is in making the details work out. But if you look at their latest video (just below the jump), we think that you’ll agree that they’ve ironed out most of the wrinkles.

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400 Transistors And 1800 Resistors Form This 1967 Personal Computer

October 29, 2015 by 58 Comments

What kind of computer could you build in 1967? Well, if you were reading Wireless World (a UK magazine) and had a good bit of spare cash, you could build [Brian Crank’s] Wireless World Computer. You only needed 400 germanium transistors, 1800 resistors, and an odd number of capacitors, switches, diodes, and neon bulbs. You also needed a good bit of patience, we suspect.

In 1967, the computer cost about 50 pounds to build (perhaps $125 at 1967 exchange rates which would now be about $900 in today’s money). To save parts (and thus money and build complexity), the computer used a trick: it processed data one bit at a time. Many older computers did this, including another UK computer named EDSAC.

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Tiny Radio Tracks Your Balloons

October 28, 2015 by 38 Comments

The name of the game in rocketry or ballooning is weight. The amount of mass that can be removed from one of these high-altitude devices directly impacts how high and how far it can go. Even NASA, which estimates about $10,000 per pound for low-earth orbit, has huge incentives to make lightweight components. And, while the Santa Barbara Hackerspace won’t be getting quite that much altitude, their APRS-enabled balloon/rocket tracker certainly helps cut down on weight.

Tracksoar is a 2″ x .75″ x .5″ board which weighs in at 45 grams with a pair of AA batteries and boasts an ATmega 328P microcontroller with plenty of processing power for its array of on-board sensors. Not to mention everything else you would need like digital I/O, a GPS module, and, of course, the APRS radio which allows it to send data over amateur radio frequencies. The key to all of this is that the APRS module is integrated with the board itself, which saves weight over the conventional method of having a separate APRS module in addition to the microcontroller and sensors.

As far as we can see, this is one of the smallest APRS modules we’ve ever seen. It could certainly be useful for anyone trying to save weight in any high-altitude project. There are a few other APRS projects out there as well but remember: an amateur radio license will almost certainly be required to use any of these.