Hackaday Prize Finalist: A Portable SDR

November 5, 2014 by 74 Comments

No other project to make it to The Hackaday Prize has people throwing money at their computer screen hoping something would happen than [Michael Colton]’s PortableSDR. It’s a software defined radio designed for coverage up to 30MHz. Amateur radio operators across the world are interested in this project, going so far as to call this the first Baofeng UV-5R killer. That’s extremely high praise.

[Michael] was kind enough to sit down and answer a few questions about how his entry to The Hackaday Prize has gone. You can check that out below, along with the final round video of the project. Anyone who wants their own PortableSDR could really help [Michael] out by taking this survey.

Continue reading “Hackaday Prize Finalist: A Portable SDR” →

Reinventing The Wheel Makes For A Better Wheel…

November 5, 2014 by 40 Comments

When robots take over the earth, it will be important that they maneuver across various types of terrain quickly and effectively. Bipedal motion is a tricky feat to accomplish for machines, so [Carter Hurd] decided, why not invent a better wheel? Even wheels can be improved, right?

Making excellent use of the prototyping capabilities of a 3D printer, [Carter] designed a set of bulb-shaped mechanisms which act effectively to drive themselves around on a smooth surface. The bulb is split radially into a series of wedge slices which can articulate outward, transforming the robot into something of a spiky razor-beast, able to tear through piles of fall leaves or wakes of loose sand. In order to unfurl itself however, the shaft driving the central mounting plate of the wedges has to fight the robot’s own weight. To solves this, [Carter] modified his design so that the rest of the wedges would unfold around the one supporting the load, the wheels would then rotate to shift the weight, allowing the last piece to extend.

[Carter] shows a proof of concept from earlier this year, explaining his hinge design which stretches a tendon-like connector in order to tension the wedges in one state or the other. Since then it looks like his transforming wheel has evolved a bit. You can get a better view of his robot in action here :

Continue reading “Reinventing The Wheel Makes For A Better Wheel…” →

Atari Video Game Burial Hits Ebay

November 5, 2014 by 47 Comments

1983 was the year of the great video game crash, and after the chiefs of Atari realized they had produced more copies of Pac-Man than consoles sold, these games, along with other ‘treasures’ were loaded into trucks, shipped out to the desert, and buried in a New Mexico landfill. Last year, these consoles were rescued. Now, thanks to the efforts of the Tularosa Basin Historical Society, these cartridges are for sale again.

Want to grab your own copy of E.T., Asteroids, Star Raiders, or Centipede rescued from a landfill in a desert? Here’s a link to the seller on eBay, with the highest auction being E.T., in box, going for $400 with nine days left. The auction comes with a certificate of authenticity from the city of Alamogordo.

This is only the first batch of cartridges and boxes rescued from the dump, with the Tularosa Basin Historical Society putting at least another 700 items up for sale if this batch goes well.

With the rousing success of this bit of dumpster diving, we must point out another techno-archeological myth/legend: there are several thousand Apple Lisas in a Utah landfill, just waiting for someone to come in and pick through the remnants of an Apple tax writeoff.

Ultra-powerful Pneumatic Hand Dryer

November 4, 2014 by 34 Comments

Have you been let down by the inadequate performance of a hand dryer? We know that feel. [tesla500] recently installed a centralized compressed air system and decided he might as well do something interesting it, so he built an ultra-powerful hand dryer that rivals the performance of any hand dryer on the market.

[tesla500] set out to make a clone of the Dyson Airblade. He started out with a simple prototype out of milled aluminum with one nozzle. Even with just one nozzle the hand dryer performed incredibly well. Next he designed a Solidworks model with a smaller nozzle gap (50um) and 4 total nozzles which has even better performance and emulates the airflow of the Airblade.

The dryer was originally controlled with a foot-activated pneumatic valve, but it severely restricted airflow. [tesla500] decided to use a 3/8″ solenoid valve instead, which solved the airflow restriction. According to [tesla500], the dryer works even better than the Airblade when running at full pressure, although he notes that you might need to watch out if you have any open wounds on your hands.

Using A Headphone Jack As A UART

November 4, 2014 by 38 Comments

We’ve seen audio ports being used to establish a communications channel between a computer and a microcontroller before, but nothing quite as slick as this. [Gordon] is using a webpage running on a tablet to send Javascript to a microcontroller where the entire program is interpreted.

[Gordon] is using the Espruino Pico, a board that’s on Kickstarter right now. This tiny board is built around a javascript interpreter, allowing code to be written and updated on the fly without mucking around with bootloaders.

This technique can be expanded to provide bidriectional communication between a microcontroller and a computer. On the project Github, [Gordon] used the microphone pin on a TRRS jack to sent data to a computer. It needs two more resistors, but other than that, it’s as simple as the one-way communications setup.

[Gordon] put together a few demos of the program, including one that will change the color of some RGB LEDs in response to input on a webpage.

Continue reading “Using A Headphone Jack As A UART” →

SDR: Satellite Death Receiver

November 4, 2014 by 18 Comments

Halloween may be over, but [happysat] has found a way to listen to the dead. Satellites, that is, specifically those in the 136-138 MHz and 150-400 MHz ranges. He’s using an RTL-SDR dongle and a QFH antenna to detect the death throes of decommissioned navigation and space research satellites.

[happysat] was listening to NOAA/Meteor on the 137MHz band when he made this discovery. When a satellite is near end of life, the last bit of fuel is used to push it into graveyard orbit. This doesn’t always work, however, and when the light is just right, a chemical reaction makes the long-dead batteries conduct and these satellites in purgatory transmit once more.

They’re not sending out anything proprietary useful, just unmodulated carrier that sometimes interferes with currently operational satellites on the 136-138 MHz band. [happysat] captured some audio from two of the oldest satellites that are still broadcasting, and links to a TLE set of dead satellites he created. Check out his frequency database for SDR# as well. Don’t have a weather satellite-capable antenna? Build one!

[via /r/RTLSDR]

A Tiny Arcade Machine With Tinier Buttons

November 4, 2014 by 15 Comments

Building a MAME machine around a Raspberry Pi has been the standard build for years now, and tiny versions of full-sized arcade machines have gone from curiosity to commonplace. [diygizmo] just built one of these tiny arcades, but the fit and finish of this one puts it above all others. There’s a real, miniature joystick in there, along with 3D printed adapters for tact switches to make this one look like a lilliputian version of a full size standup MAME cabinet.

The entire enclosure is 3D printed, and most of the electronics are exactly what you would expect: A Raspberry Pi, 2.5″ LCD, and a battery-powered speaker takes up most of the BOM. Where this build gets interesting is the buttons and joystick: after what we’re sure was a crazy amount of googling, [diygizmo] found something that looks like a normal arcade joystick, only smaller. Unable to find a suitable replacement for arcade buttons, [diygizmo] just printed their own, tucked a tact switch behind the plastic, and wired everything up.

Add in some decals, paint, and the same techniques used to create plastic model miniatures, and you have a perfect representation of a miniature arcade machine.