Hackaday Links: Sunday, June 30th, 2013

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The race is on to squeeze cycles out of an 8MHz AVR chip in order to better drive the WS2811 LED protocol.

[Asher] doesn’t want to buy charcoal aquarium filters if he can just build them himself. He filled a couple of plastic drink bottles with charcoal, cut slots in the sides, and hooked them up to his pump system. A gallery of his work is available after the break.

Is the best way to make microscopic sized batteries to 3d print them? Harvard researchers think so. [Thanks Jonathan and Itay]

The Ouya gaming console is now available for the general public. [Hunter Davis] reports that the Retrode works with Ouya out-of-the-box. If you don’t remember hearing about it, Retrode reads your original cartridge ROMs for use with emulators.

Making a cluster computer out of 300 Raspberry Pi boards sounds like a nightmare. Organization is the key to this project.

Hackaday alum [Jeremy Cook] is working on an animatronic cigar box. Here he’s demonstrating it’s ability to listen for voice commands.

A Kelvin clips is a type of crocodile clip that has the two jaws insulated from each other. [Kaushlesh] came up with a way to turn them into tweezer probes.

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Air-powered Gripper Design Makes Them Easy To Produce

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This invertebrate gripper uses air pressure to grab onto objects. The secret is all in the design. But you don’t have to reinvent the wheel. If you’ve got a 3D printer you can follow this guide to make your own.

The gripper is made of silicone. The trick is in designing an inner structure that deforms in one direction when pressurized. To make one or one hundred, simply download the design files and 3D print a mold. The process from there is much like the silicone band prototyping process we looked at back in March. The two-part silicone is mixed and poured in the mold. You also need to pour some on a flat surface. We were under the impression that uncured silicone would not stick to cured silicone but we were wrong. The two parts are glued together with a fresh batch of the mix. After everything has set up you can pierce the bladder with a hose in order to inject air.

Below you can see the star-shaped version being tested. There’s also a Harvard research video which shows a similar design lifting an egg.

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Retrotechtacular: Bell Labs Introduces A Thing Called ‘UNIX’

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Modern operating systems may seem baroque in their complexity, but nearly every one of them  – except for Windows, natch – are based on the idea of simplicity and modularity. This is the lesson that UNIX taught us, explained perfectly in a little film from Bell Labs in 1982 starring giants of computation, [Dennis Ritchie], [Ken Thompson], [Brian Kernighan], and others.

At the time this film was made, UNIX had been around for about 10 years. In that time, it had moved far from an OS cloistered in giant mainframes attached to teletypes to slightly smaller minicomputers wired up to video terminals. Yes, smallish computers like the Apple II and the VIC-20 were around by this time, but they were toys compared to the hulking racks inside Bell Labs.

The film explains the core concept of UNIX by demonstrating modularity with a great example by [Brian Kernighan]. He took a short passage from a paper he wrote and found spelling errors by piping his paper though different commands from the shell. First the words in the paper were separated line by line, made lowercase, and sorted alphabetically. All the unique words were extracted from this list, and compared to a dictionary. A spell checker in one line of code, brought to you by the power of UNIX.

Google Science Fair Finalist Explains Squid-inspired Underwater Propulsion

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Meet [Alex Spiride]. He’s one of the fifteen finalists of the 2013 Google Science Fair. A native of Plano, Texas, [Alex] entered his squid-inspired underwater propulsion system in the 13-14 year old category.

The red cylinder shown in the image inlay is his test rig. It is covered well on his project site linked above. You just need to click around the different pages using the navigation tiles in the upper right to get the whole picture. The propulsion module uses water sprayed out the nozzle to push the enclosure forward. The hull is made of PVC, with a bladder inside which is connected to the nozzle. The bladder is full of water, but the cavity between it and the hull is full of air. Notice the plastic hose which is used to inject pressurized air, squeezing the bladder to propel the water out the nozzle. Pretty neat huh?

We think [Alex’s] work stands on its own. But we can’t help thinking what the next iteration could look like. We wonder what would happen if you wrapped that bladder in muscle wire? Would it be strong enough to squeeze the bladder?

You can see all fifteen finalists at the GSF announcement page. Just don’t be surprised if you see some of those other projects on our front page in the coming days.

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