An Arduino Power Inverter

June 21, 2013 by 32 Comments

If you’ve got a few solar panels lying around, or even if you want some 120/230 V AC power from a few 12 Volt batteries, you’ll need a power inverter. Sure, you can drop on down to any big box store and pick one of these up, or you can be like [Michael] and build your own (Danish, translation).

[Michael] found himself in the possession of a few halogen light transformers and decided to make use of them by building a DC to AC power inverter. The inverter is fairly simple – just the transformer, a few MOSFETS, and an ATMega0168 for software control that includes a ‘soft start’ feature that prevents power surges on startup.

The circuit is simple enough to etch at home, although a soldermask and a nice insulated enclosure would probably be ideal for this application.

Building A Synth On A Breadboard

June 21, 2013 by 12 Comments

synth

Building an analog synth is a challenge, but with the [Tymkrs] protosynth, it’s easier than ever. It’s a 25-key keyboard attached to a stack of solderless breadboards to make analog synth prototyping a snap.

Earlier, [Tymkrs] acquired a whole bunch of solderless breadboards and decided to put them to use by making a component-level modular synth. The earlier incarnation tied each key on the keyboard to a few wires behind the breadboard and tied them in to a shift register so they could be read with a Propeller dev board loaded up with a Commodore SID emulator. The new version keeps the very clean through-the-back keyboard connector, but this time the [Tymkrs] are adding a few more components that add a sequencer setup and a rotary encoder.

The eventual goal for this really cool breadboard synth is to explore the world of Moogs, Arps, and other analog synths easily on a breadbaord. The [Tymkrs] have already put together a breadboard-compatible low pass and high pass filter. While there’s still a lot of work to be done to make an analog synth a reality, the [Tymkrs] are off to a great start.

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Hacking A Medion WiFi Streaming Radio Found At Aldi

June 21, 2013 by 20 Comments

hacking-medion-streaming-wifi

On a shopping trip at Aldi [Aaron Christophel] came across this Medion streaming device which connects to your home network via WiFi and works as an Internet radio. He couldn’t resist buying one, and managed to do quite a bit of hacking on the device (translated) once he got it home.

His first order of business was a hardware teardown. An inspection of the board showed what was obviously an unpopulated footprint for a USB mini jack. He added the component, thinking it would allow him to connect it to a computer, but that didn’t work. To investigate the issue further he connected to the device’s serial port using the hard-to-guess credentials root and password. It’s running a Linux kernel and the lsusb command revealed that the USB is enabled as host mode. This mean you can attach mass storage… sweet!

He also did some firmware hacking. Above is the confirmation screen for flashing his altered image file. This resulted in a custom splash screen when it boots up.

A Folding Knife Made From Scratch

June 21, 2013 by 2 Comments

thisisaknife

 

[bobasaurus] over on reddit had a go at making a knife from scratch. It was his first attempt, but we’re thinking the result is fabulous and a wonderful example of what can be done with minimal tools at home.

The blade and folding mechanism was crafted out of an O1 tool steel bar. [bob] didn’t have any fancy machines like a bandsaw to cut these metal parts out; he used a jeweler’s saw and went through many blades in the process.

After the basic shape of the metal parts took form, [bob] turned to the scales. They’re made of a beautiful figured wood, bocote, native to Central America.

One interesting part of [bob]’s knife is the electrochemical etching he did on the blade. After applying a mask for the etching with the toner transfer process, the blade was grounded to a battery charger and a paintbrush wired up to the positive side was dipped in salt water. It’s certainly an easy way to engrave metal without investing in expensive tools or a CNC router.

Finally, the scales were shaped and oiled and the blade and bolster mechanism installed. A lot of work went into this knife, especially with the bare minimum of tools [bob] used. The results are worth it, though, and he ended up with a beautiful knife.

Solar Powered Hovercraft

June 20, 2013 by 16 Comments

SONY DSC

It looks a little bit like an octocopter, but this solar-powered hovercraft is distinctly different from its free-flying brethren. It depends mostly on ground effect for operation and to get it just a bit into the air you need a pretty large reflective rig nearby.

The vehicle needs to be even lighter than traditional quadcopters in order to function. It doesn’t carry any battery at all which presents a problem when trying to program the microcontroller board. For this it is connected to an external battery, which is removed before flight so that the control can be powered from the solar array.

What’s not shown in the image above is a mirror array used to focus more intense sunlight on the panels to bump up the available electricity. Not much is said about this, but there is one image on the project page which shows the creator standing in front of the set of four mirrors (perhaps sheets of mylar?) strung up between a couple of trees.

Alas, we couldn’t find a video of the aircraft in action. With such a delicate balsa wood frame we’re sure this thing is affected by every air current that passes its way.

[Thanks Laimonas]

Building Custom Game Controllers For People With Physical Disabilities

June 20, 2013 by 81 Comments

 

Hold on tight. This is going to be a long post. I kept my temper in the video, but here I can just come out and let you know that I’m livid. Every time I start thinking about this, I feel so angry and helpless that my face gets hot and my hands get shaky.  I’m getting ahead of myself though, so lets just back up a little bit and talk about a pretty cool kid named [Thomas].

[Thomas] has muscular dystrophy. This means he’s going to gradually lose strength and control in his muscles over time. He has already lost his ability to stand, and even holding buttons on a game-pad for extended times can be difficult. Gaming, as you can imagine, is very important to [Thomas] and people like him. It offers a release of frustration, like it does for all of us, but also a level playing ground. When he’s in the game, he’s like everyone else.

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Modeling Squid Cells In Code Foregoes Connecting Voltage To Animals

June 20, 2013 by 4 Comments

[Kemper Smith] built a little piece of nature in Processing. He was inspired by a biology experiment that excited squid cells using electricity. The result is an interactive display that mimics that biology.

Last August we saw a peculiar experiment that forced Cyprus Hill music on the color changing cells of a squid. The cells make colors by stretching sacs of pigment; the larger they get the more of that color is shown. Normally this is used for camouflage. The image on the left is the reaction from connecting headphone wires while music is being played.

But we can’t all get our hands on this type of wet-ware — especially if life far inland. So [Kemper] got to work writing some Processing code. The result is seen on the right. It does a good job of replicating the motion and color palette of the original. He’s put together a web-based demonstration which you can interact with using your mouse cursor. But we also saw him demonstrate a Kinect based version at our local hackerspace.

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