Nearspace Environmental Chamber

November 16, 2013 by 30 Comments

vacuum

If you’re going to send some hardware up to 100,000 feet, where atmospheric pressure is 1% of what we enjoy on the surface and temperatures swing down to where Fahrenheit and Celsius don’t matter anymore, you might want to do a bit of testing to make sure everything works before launch. With a few bits of PVC, though, that’s a piece of cake.

There were several environmental conditions to take into consideration; the near vacuum experienced by high altitude balloons would be replicated by a refrigerator compressor, the increased solar flux is simulated by a light bulb, and the cold temperatures provided by a chunk of dry ice.

For a proper high altitude, low temperature environmental chamber the test payload should be cooled down via radiation with tubes filled with liquid nitrogen embedded in the walls. This is the NASA way of doing things, but for the budget of $200, [arko]’s chamber simulates a high altitude environment just fine.

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Should All Quadrotors Look Like This?

November 16, 2013 by 53 Comments

In recent years, quadrotors have exploded in popularity. They’ve become cheap, durable, and can do some really impressive things, but are they the most efficient design? The University of Queensland doesn’t think so.

Helicopters are still much more efficient and powerful due to their one big rotor, and with the swashplate mechanism, perhaps even more maneuverable — after all did you see our recent post on collective pitch thrust vectoring? And that was a plane! A few quick searches of helicopter tricks and we think you’ll agree.

The new design, which is tentatively called the Y4, or maybe a “Triquad” is still a quadrotor, but it’s been jumbled up a bit, taking the best of both worlds. It has a main prop with a swashplate mechanism, and three smaller rotors fixed at 45 degree angles, that provide the counter torque — It’s kind of like a helicopter with three tails.

Regarding efficiency, the researchers expect this design could achieve an overall increase of about 25% in performance, compared to that of a standard quadrotor. So, they decided to test it and built a quad and a Y4 as similar as possible — the same size, mass, batteries, arms, and controller board. The results? The Y4 had an increased run time of 15%! They think the design could very well make the 25% mark, because in this test study, the Y4 was designed to meet the specifications of the quad, whereas a more refined Y4 without those limitations could perhaps perform even better.

Unfortunately there’s no video we can find, but if you stick around after the break we have a great diagram of how (and why) this design works!

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Original NES Advantage Controller Stuffed With Clone NES

November 16, 2013 by 4 Comments

famiclone-inside-NES-advantage

Like all good hackers [Osgeld] makes regular appearances at the thrift store to scavenge for raw materials. This summer he was lucky enough to come across a couple of NES clone games. These are controllers that emulate the original Nintendo Entertainment System by connecting to a television using composite video. The mechanics of the controllers were pretty much shot, but he knew he could do something with the boards inside. It was a small gamble at a dollar apiece anyway.

As you can see above, he upgraded a vintage NES Advantage controller by stuffing it full of the emulator hardware. To start he disassembled the arcade-like peripheral and gave everything a thorough cleaning. Since he was going to be soldering onto the PCBs anyway he upgraded the controller by swapping out the original switches for a different set of tactile switches. The large base provided plenty of room for [Osgeld] to fit the emulator (with included ROMs) and now he’s Playing with Power.

The NES Advantage is a very nostalgic controller. Even the Ghostbusters hacked on it!

FT230X Brings USB Charging Detection To The Serial IC Game

November 16, 2013 by 4 Comments

FT230XS-breadboard

Here’s a new chip from FTDI which brings a nice little feature to the USB-to-serial converter family: charging detection. That means that it is capable of detecting when a battery charger is connected. What does that actually mean? The top of the datasheet gives you the short version, but let’s look at the investigation [Baoshi] undertook to test the full extent of this particular feature. We agree with him that the listed capability leaves those in the know with a lot of questions:

USB Battery Charger Detection. Allows for USB peripheral devices to detect the presence of a higher power source to enable improved charging.

Obviously the chip will be able to tell when a charger is connected, alerting the device when it’s time to start lapping up the extra milliamps. But what type of chargers will actually trigger the detection circuit? After rigging up the test circuit shown above he ran through several scenarios: connected directly to the PC USB port, via externally powered and non-powered USB hubs, and with multiple wall wart chargers. Full results of the tests are included in the post linked above.

[via Dangerous Prototypes]

20 Android Tablets Form An Interactive Photo Collage

November 15, 2013 by 20 Comments

You might not have a small army of unused tablets lying around, but if you did, you should try turning them into what Minn calls a “Giant Interactive Photo Array Display:” A Giant IPAD. Har har.

[Minn’s] first step was to hit eBay, hoping to find a score of low-priced, broken-yet-easily-repairable tablets. The only ones available (and for cheap), however, were resistive touch screens with narrow viewing angles. After waiting patiently for nearly half a year, [Minn] hit the capacitive touch jackpot: snagging a pile of 10″ and 7″ Android tablets. The frame is custom made to provide a solid surface for mounting and enough depth for the tablets to fit correctly. Rather than form his own brackets to hold each device, [Minn] re-purposed some IKEA cupboard handles, screwing them into the MDF backboard and clamping the tablets to them with bolts that press against the case. An adhesive rubber bumper stuck to the top of the bolts prevents any damage.

Providing power to the diverse collection required another custom solution; two 5V 10A supplies and one 9V 16A supply fit into an accompany box safely deliver the needed juice. [Minn] chose an app that will grab photos from cloud storage so he can update the collection without having to dig around inside the frame. See the result in a video below! Want to try this project but only have one tablet to spare? The in-wall tablet mount might help.

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Automated Aquarium Is Kitchen-Sinky

November 15, 2013 by 16 Comments

fishtankAutomation

People have been converting their old Power Macs and Mac G5s into fish tanks for a few years now, but [Hayden’s] Internet-enabled tank is probably the most awesome ever crammed into an aquarium along with the water and the fish—and we’ve seen some fascinating builds this summer. After gutting the G5 and covering the basic acrylic work, [Hayden] started piling on the electronics: a webcam, timed LED lighting, an LCD for status readouts, filter and bubble control via a servo, an ultrasonic sensor to measure water levels, thermometer, scrolling matrix display, an automatic feeding mechanism, and more. He even snuck in the G5’s old mainboard solely for a cool backdrop.

The build uses both a Raspberry Pi and an Arduino Mega, which sit underneath the tank at the base. The Pi provides a web interface written in PHP and jQuery, which presents you with the tank’s status and allows changes to some settings. Nearly every component received some form of modification. [Hayden] stripped the webcam of its case and replaced the enclosure with a piece of acrylic and a mountain of silicone, making it both waterproof and slim enough to fit in the appropriate spot. Though he decided to stick with an Amazon-bought Eheim fish feeder, he disabled the unit’s autofeed timer and tapped in to the manual “feed” button to integrate it into his own system.

It’d take half of the front page to explain the rest of this thing. We’ve decided to let the aquarium tell you the rest of its features in the video below. Yeah…it can talk.

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Producing Ozone At 3500 RPM

November 15, 2013 by 16 Comments

motor

Motors are fun, and high voltage even more so. We’re guessing that’s what went through [brazilero2008]’s mind when he put together an electrostatic motor using upcycled parts he found lying around.

The electrostatic rotor works by connecting a very high voltage, low current power supply – in this case an industrial air ionizer – to a set or rotors surrounding a plastic rotor. The hot electrodes spray electrons onto the rotor, which are picked up by the ground electrodes. If the system doesn’t arc too much, you have yourself a plastic rotor that spins very, very fast.

[brazilero]’s device is made out of an aluminum turkey pan, a few acrylic tubes, and a few cardboard disks; all stuff you can find in a well-stocked trash can. After completing the device, it was taken apart and finished and screwed onto a beautiful painted jewelry box. Very cool for something you can make out of trash, and dangerous enough to be very interesting.

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