Store Your RFID Transit Card Inside Your Cellphone

July 17, 2012 by Mike Szczys 54 Comments

Check it out, this is a Boston transit pass — or at least the parts of it that matters. [Becky Stern] got rid of the rest in a bid to embed the RFID tag inside her cellphone.

The transit pass, called a CharlieCard, started out as a normal credit card shaped tag which you might use for access in the workplace. She unsheathed the chip and its antennae by giving it a generous soak in acetone. In about thirty minutes the plastic card looks more like paper pulp, and you can gently fish out the electronics. These are now small enough to fit in the back cover of a cellphone much like those inductive charging hacks.

[Becky] put hers in an iPhone. But the idea comes from [Dhani Sutanto] who used the same technique to extract the coil from a London transit pass. He then embedded the hardware in a resin cast ring.

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Retrotechtacular: The Birth Of Satellite Communications

July 17, 2012 by Mike Szczys 4 Comments

Last week was the fifty year anniversary of the launching of Telstar 1, the first communications satellite. Take a look back at the marvel of the early technology as shown in this newsreel footage about the first broadcast. The first formal use was a speech by President Kennedy allowing most of Europe to “witness democracy at work”. You’ve got to love that cold war era propaganda.

In addition to this electronics-filled marvel there were other experiments going on at the time that used passive devices as satellites. Project Echo sought to put reflective balloons at an altitude where they could be used to bounce signals around the curvature of the earth. This came almost exactly two years before the advent of Telstar 1.

There was a lot of media coverage of this anniversary, but the most interesting for us was an NPR interview with [Walter Brown], one of the engineers who helped build the device. Apparently nuclear weapons testing in space the day before the launch caused the initial tests to fail.

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Lightweight Web Server Using The MSP430

July 17, 2012 by Brian Benchoff 17 Comments

Need a tiny web server? [Rob] over on the 43oh forums made an Ethernet booster pack for the very popular TI MSP430 microcontroller. If that’s not enough, [Rob] also put together an all-in-one solution with a MSP430 and Ethernet controller that can be powered by a battery. Along with the web server that fits in just 5k of flash, we’re going to say [Rob] has a very good solution for remote sensing and data logging.

For his Ethernet-enabled 430, [Rob] chose to use the WIZnet W5200 Ethernet controller. This chip communicates with the 430 via and SPI interface and has a hardware TCP/IP stack that supports TCP, UDP, and PPPoE, offloading all the low-level stuff off of the 430 and onto the Ethernet controller.

After the break there are a pair of videos of [Rob] showing off his tiny web server. A few neat features include a full memory dump of the 430, as well as a reading the states of all the pins via an HTML page. If you’re looking for a way to collect data over Ethernet, we don’t think you could do better than [Rob]’s tiny 430-based web server. Also, if you’d like to control a few devices over the Internet, [Rob] included a few optoisolators for lights or appliances.

The code is available on the 43oh forum page, but [Rob] says he’ll clean that up and put it in a Git.

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Finger Recognition On The Kinect

July 17, 2012 by Brian Benchoff 9 Comments

The Kinect is awesome, but if you want to do anything at a higher resolution detecting a person’s limbs, you’re out of luck. [Chris McCormick] over at CogniMem has a great solution to this problem: use a neural network on a chip to recognize fingers with hardware already connected to your XBox.

The build uses the very cool CogniMem CM1K neural network on a chip trained to tell the difference between counting from one to four on a single hand, as well as an ‘a-okay’ sign, Vulcan greeting (shown above), and rocking out at a [Dio] concert. As [Chris] shows us in the video, these finger gestures can be used to draw on a screen and move objects using only an open palm and closed fist; not too far off from the Minority Report and Iron Man UIs.

If you’d like to duplicate this build, we found the CM1K neural network chip available here for a bit more than we’d be willing to pay. A neural net on a chip is an exceedingly cool device, but it looks like this build will have to wait for the Kinect 2 to make it down to the consumer and hobbyist arena.

You can check out the videos of Kinect finger recognition in action after the break with World of Goo and Google Maps.

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Make A Game For A Retro Console, Win Prizes

July 17, 2012 by Brian Benchoff 2 Comments

For all you old-school console hackers out there, there’s a homebrew coding competition being held by NeoTeam for all the retro (and not so retro) consoles of yesteryear. If you’ve ever programmed for the NES, GBA, PC Engine, N64, or even the Dreamcast, now’s your chance to write a game or app and hopefully win a small prize and a great deal of street cred.

Last year, the Neo Coding Competition saw some very cool entries such as [smealum]’s amazing work in bringing Minecraft to the Nintendo DS ([smealum]’s non-forum DScraft page is here). DScraft won [smealum] a cool $500 USD, but the bragging rights for bringing Minecraft to the DS are far more valuable than any monetary reward.

There are two categories for the competition, an app division and a game division. All the retro platforms are open for development in this contest, so if you want to write something for your Master System, NES, 32X, or Saturn, you better get started: the contest ends August 20th.

ATX Benchtop Conversion Retains Safety Features, Delivers Plenty Of Current.

July 17, 2012 by Mike Nathan 11 Comments

atx-benchtop-psu

[Bogin] was looking to add a benchtop power supply to his array of tools, but he didn’t really find any of the online tutorials helpful. Most of what he discovered were simple re-wiring jobs utilizing LM317 regulators and shorted PS-ON pins used to keep the PSUs happily chugging along as if nothing had been changed. No, what [Bogin] wanted was a serious power supply with short circuit protection and loads of current.

He started the conversion by disassembling a 300 watt ATX power supply that uses a halfbridge design. After identifying the controller chip, a TL494 in this case, he proceeded to tweak the PWM feedback circuit which controls the supply’s output. A few snips here, a few passes with a soldering iron there, and [Bogin] was ready to test out his creation.

He says that it works very well, even under heavy load. His tutorial is specific to these sorts of PSUs, so we would be more than happy to feature similar work done with those that implement other design topologies. In the meantime, be sure to check out a video of the hacked power supply in action below.

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Cracking Open An Ancient Avionics Gyroscope

July 16, 2012 by Mike Szczys 26 Comments

This artificial horizon might as well have come from an alien ship. [Mike] somehow manages to get his hands on most interesting equipment, this time its a very old piece of avionics equipment. The mechanical gyroscope functioned as the artificial horizon, and he’s going to take us inside for a look. He doesn’t spend quite as much time on it as he did that thermal imaging camera, but this electro-mechanical odyssey is just as interesting.

To get the accuracy needed to help keep a plane in the air (well to keep the pilot well-informed anyway) the device needed to be very well manufactured. [Mike] comments several times along the way on how the different rotating parts are so well-balanced and machined that they seem nearly frictionless. It appears that a lot of the positional feedback depends on wirewound resistor rings which connect to a rotating piece via a series of very fine spring wires. As the parts rotate the resistance changes and that’s what gives the feedback. There are also mercury switches to help along the way.

He does his best to explain, but to us the inner workings are still a big mystery. See if you can get a clearer picture from the video after the break.

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