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Hands On With The Odroid C2; The Raspberry Pi 3 Challenger

March 16, 2016 by 116 Comments

A couple of weeks ago we covered the launch of the Odroid C2, a single board computer from the Korean company Hardkernel in the same form factor and price segment as the Raspberry Pi 3. With four ARM Cortex A53 cores at 2GHz and 2Gb of DDR3 on board it has a paper spec that comfortably exceeds that of the Pi 3’s 1.2GHz take on the same cores and 1Gb of DDR2. This could be a board of great interest to our readers, so we ordered one for review.

The parcel from Korea arrived in due course, the C2 in its box inside it well protected by a sturdy cardboard outer packaging. We had ordered a couple of extras: a micro-SD card preloaded with Ubuntu and a USB power lead (more on that later), both were present and correct.

When unpacking the board it is immediately obvious how closely they’ve followed the Raspberry Pi form factor. There are a few differences, no camera or DSI connectors, the SD card in a different place, a power jack where the Pi has its audio jack, and oddly the network port is the other way up. Otherwise it looks as though it should fit most Pi cases. Of course the only case we had to hand was a PiBow which are cut for specific Pi models, so sadly we couldn’t test that assertion.

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Hacker Straightens Own Teeth

March 16, 2016 by 49 Comments

So you say your wonky smile has you feeling a bit self-conscious? And that your parents didn’t sock away a king’s ransom for orthodontia? Well, if you have access to some fairly common fab-lab tools, and you have the guts to experiment on yourself, why not try hacking your smile with DIY braces?

First of all: just – don’t. Really. But if you’re curious about how [Amos Dudley] open-sourced his face, this is one to sink your teeth into. A little research showed [Amos] how conventional “invisible” braces work: a 3D model is made of your mouth, each tooth is isolated in the model, and a route from the current position to the desired position is plotted. Clear plastic trays that exert forces on the teeth are then 3D printed, and after a few months of nudging teeth around, you’ve got a new smile. [Amos] replicated this hideously expensive process by creating a cast of his teeth, laser scanning it, manipulating the teeth in 3D modeling software, and 3D printing a series of intermediate choppers. The prints were used to vacuum mold clear plastic trays, and with a little Dremel action they were ready to wear. After 16 weeks of night and day wear, the results are pretty amazing – a nicely aligned smile, and whiter teeth to boot, since the braces make great whitening trays.

Considering how badly this could have turned out, we’ve got to hand it to [Amos] for having the guts to try this. And maybe he’s onto something – after all, we’ve advocated for preemptive 3D scanning of our bodies recently, and what [Amos] did with this hack is a step beyond that.

[LupusMechanicus], thanks for the tip!

Pick Locks Like In The Movies: Using A Bobby Pin

March 15, 2016 by 44 Comments

Sure, many of us don’t hold our hair in place with bobby pins, but just in case we need to break into a secure location, like the broom closet we locked ourselves out of, it wouldn’t hurt to know how to use them to pick a lock.

There are worse things you can make a lockpick set out of. After you’ve secured two bobby pins, one for the tension wrench and one for a small hook pick. To make the small hook simply flatten the pick and remove the rubber cap from the side without waves; this is the small hook. To make the tension wrench, bend the second pin in half. Simple.

The guide also functions as a very good beginner tutorial on lock-picking, covering the types of simple locks one is likely to encounter, and the various shortcomings of their construction that could impede efforts to open them. The whole site is a good resource for those who enjoy the art.

After that it is standard lock picking. Put torsion on the barrel and prod those pins into place with your reconfigured fashion accessories.

The Origin Of QWERTY

March 15, 2016 by 73 Comments

There are very few things that are surrounded with as much hearsay and rumor as the origins of the QWERTY layout of typewriters and keyboards. The reason behind the QWERTY layout isn’t as simple as ‘so the bars for each letter don’t collide with each other.’ That’s nonsense – it would make far more sense to improve the mechanism before changing the arrangement of the keyboard around.

That’s not the only fallacious argument for the creation of QWERTY. It’s also been called a marketing ploy; Stephen Jay Gould popularized the idea of the QWERTY keyboard being as it is so a salesman could peck out TYPE WRITER on the top row [1]. This also makes little sense. Why would the top row and not the home row be so privileged as to contain all the letters the make up the name of the machine. For that matter, wouldn’t a sales pitch be more impressive if TYPE WRITER were typed with one hand?

This doesn’t mean there’s not a method behind the madness of QWERTY – it’s just not as simple as jammed typewriter mechanisms or appeasing the wishes of salesmen in the 1870s. QWERTY didn’t come out of thin air, though, but folk tale history of this keyboard layout is sadly deficient.

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SDRAM Logic Analyzer Uses An AVR And A Dirty Trick

March 15, 2016 by 58 Comments

We often see “logic analyzer” projects which are little more than microcontrollers reading data as fast as they can, sending it to a PC, and then plotting the results. Depending on how fast the microcontroller is, these projects range from adequate to not very useful.

At first glance, [esot.eric’s] logic analyzer project has an AVR in it, so it ought to be on the low end of the scale. Then you look at the specs: 32 channels at 30 megasamples per second. How does that work with an AVR in it?

The answer lies in the selection of components. The analyzer uses a 128MB SDRAM DIMM (like an older PC might use for main memory). That makes sense; the Arduino can’t store much data internally. However, it isn’t the storage capacity that makes this choice critical. It seems [esot.eric] has a way to make the RAM “free run”.

The idea is to use the Arduino (or other host microcontroller) to set up the memory. Some of the memory’s output bits feedback to the address and data lines. Then the microcontroller steps aside and the SDRAM clocks samples into its memory by itself at the prevailing clock rate for the memory.

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Prime Numbers Are Stranger Than You Thought

March 14, 2016 by 135 Comments

If you’ve spent any time around prime numbers, you know they’re a pretty odd bunch. (Get it?) But it turns out that they’re even stranger than we knew — until recently. According to this very readable writeup of brand-new research by [Kannan Soundararajan] and [Robert Lemkein], the final digits of prime numbers repel each other.

More straightforwardly stated, if you pick any given prime number, the last digit of the next-largest prime number is disproportionately unlikely to match the final digit of your prime. Even stranger, they seem to have preferences. For instance, if your prime ends in 3, it’s more likely that the next prime will end in 9 than in 1 or 7. Whoah!

Even spookier? The finding holds up in many different bases. It was actually first noticed in base-three. The original paper is up on Arxiv, so go check it out.

This is a brand-new finding that’s been hiding under people’s noses essentially forever. The going assumption was that primes were distributed essentially randomly, and now we have empirical evidence that it’s not true. What this means for cryptology or mathematics? Nobody knows, yet. Anyone up for wild speculation? That’s what the comments section is for.

(Headline photo of researchers Kannan Soundararajan and Robert Lemke: Waheeda Khalfan)

Engineer Humanity’s Future: The 2016 Hackaday Prize

March 14, 2016 by 61 Comments

Today we are proud to launch the 2016 Hackaday Prize. Build Something That Matters and you’ll contribute positively to humanity’s future by expand the frontiers of knowledge and engineering. You’ll also score recognition of your skills, and position yourself to land one of 105 cash prizes totaling over $300,000. Choose a technology issue facing humanity today and build a project that fixes, improves, or bypasses the problem.

You have the talent, the energy, and the capacity to change the world. Make the time and make a difference.

The Hackaday Prize is a competition synonymous with creating for social change. Using your hardware, coding, scientific, design and mechanical abilities, you will make big changes in people’s lives. Every idea has impact, and a massive force of ideas creates real change. This year we have more power than ever before to recognize the engineering projects that are solving problems: One hundred finalists will get $1,000 each for their efforts. This flat prize structure encourages collaboration rather than direct competition. Team up on each others’ projects and improve your overall chances of making it into the finals.

But it doesn’t stop there. From one hundred finalists, five will rise to be named top winners. Our expert judges will carefully review each of 100 world-changing final entries, choosing a grand prize winner to receive $150,000. Second place will be awarded $25,000, with $10k, $10k, and $5k going to third, fourth, and fifth.

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