Wii Nunchuck Controlled Robot Exhibits Rock Solid Balancing

September 25, 2012 by Mike Szczys 24 Comments

[Willy Wampa] is showing off his self-balancing robot. What strikes us about the build is how well tuned his feedback loop seems to be. In the video after the break you will see that there is absolutely no visible oscillation used to keep its balance.

The parts used are quite easy to obtain. The acrylic mounting plates are his wife’s design and were custom cut through the Pololu service. They were also the source of the gear motors. He’s using a SparkFun IMU with an Arduino and a motor shield. He first posted about the build about a month ago, but the new revision switches to a Pololu motor driver shield which he says works much better, and adds control via a wireless Wii Nunchuck.

The PID loop which gives it that remarkably solid upright stance is from a library written by [Brett Beauregard]. Once again the concept of open source lets us build great things by standing on the shoulders of others.

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Speech Recognition On An Arduino

September 22, 2012 by Brian Benchoff 33 Comments

Speech recognition is usually the purview of fairly high-powered computers chugging along at hundreds of Megahertz with megabytes of RAM. Bringing speech recognition to the low-power microcontroller you’d find in an Arduino sounds like the work of a mad scientist or Ph.D. candidate, but that’s exactly what [Arjo Chakravarty] did. He developed the μSpeech library for the Arduino to allow for speech recognition for a limited set of voice commands.

Where most speech recognition systems use FFT and very fancy math to determine what phonemes a user is saying, [Arjo]’s system does away with this unnecessary complexity in favor of using very, very basic integral and differential calculus.

From [Arjo]’s user guide for μSpeech (PDF warning) we can see it’s possible to connect a small microphone to the analog input of an Arduino and accept voice commands such as ‘left’, ‘right’, and ‘stop’. The accuracy is pretty good, as well – 80% if μSpeech is trying to recognize words, and 30-40% if μSpeech is programmed to recognize single phonemes.

Sadly we couldn’t find a demo video of μSpeech in action, but you’re more than welcome to grab it via github for your own project. Send us a video of μSpeech in action and we’ll put it up.

Qube Robots Use Well-designed Laser-cut Acrylic

September 19, 2012 by Mike Szczys No comments

These robot cubes, called BOXZ, use an interesting interlocking part design to mount and protect the parts within. But to really make them pop you need to color and apply your own papercraft skins.

The actual hardware is quite simple. They’ve used an Arduino, along with motor driver and Bluetooth shields, to control a set of geared DC motors. There’s a battery pack which holds four AA cells and a pair of servo motors which seem to be there to act as arms. This base can then be adorned with sensors to add functionality (line following, wall following, obstacle avoidance, etc.).

Despite the simple appearance of the cube, the chassis is the most complicated part. It uses sixteen pieces of acrylic, but they may also be hand cut from cardboard by printing out templates and gluing them onto the material. The parts are designed with interlocking tabs which we often see used on laser-cut wooden box parts.

We’ve embedded the video presentation of BOXZ after the break.

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Scrolling Tweets With A WiFi LED Matrix

September 17, 2012 by Brian Benchoff 4 Comments

For his most ambitious build to date, [Param] thought it would be a cool idea to have a LED matrix display spitting tweets out via a WiFi connection. The build is now done, and we’ve got to hand it to him for a very nice build.

The build is based on an Arduino with a Sparkfun WiFi shield providing the network connection. The Arduino pings a Javascript app that pulls down tweets from The Verge and displays them on an 8×8 LED matrix display.

What makes [Param]’s build so cool is its portable nature; the entire device is completely wireless, getting its power from a Sparkfun LiPower shield and an apparently extremely capacious LiPoly battery.

With a rat’s nest of wires hanging out the back of the LED display, [Param]’s build is crying out for a proper enclosure, but even given that it remains a quality project. You can see a video of the WiFi’d Twitter display after the break.

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Helmet Of Many LEDs Built For Burning Man

September 14, 2012 by Mike Szczys 54 Comments

This motorcycle helmet was heavily altered to accept all of the hardware that goes into driving that huge array of LEDs. [Brian Cardellini] built it to wear at burning man. He claims to have been in over his head with the project, but we certainly don’t get that feeling when we see the thing in action. It’s light on build details, but there are plenty of demo shots in the video after the break. The animation and fading action really gets started about a minute and a half into it.

One of the early frames of the video is a shot of the parts order webpage. Since it’s an HD clip we were able to glean a few bits and pieces from that. It includes a MAX7219 LED Display Driver and fifteen 25-packs of Blue LEDs. Now that chip is a great choice, and one of the later shots shows two of them on breakout board driven by an Arduino. The look is very clean since he carved out most of the helmet’s padding to make room for the electronics.

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16×8 Pixel Laser Projector

September 14, 2012 by Mike Szczys 4 Comments

[Michiel] gave us a little shout-out by drawing the Hackaday logo with his recently completed 16×8 pixel laser projector. It uses a spinning set of mirrors mounted at slightly different angles to redirect the path of the red laser diode.

The projector is driven by an Arduino. To give it more than just a hard-coded existence [Michiel] included an Xbee module. This lets him connect to it with a computer in order to stream messages. One of the demo videos linked in his project log shows the web interface he coded which will push a message typed in the submission form out to the projector where it is scrolled like a marquee.

This type of spinning display is one of a few common methods for making laser projectors. In the image above you can see the optical sensor which is used to sync the diode with the spinning mirrors, each of which is responsible for a different row of pixels. He lists off several things that he learned when working on the project. We think the most important is the timing issues which go into something like this.

Bits And Pieces Robotic Arm

September 10, 2012 by Richard Steele 3 Comments

[V0R73X], who is 17 has been working on a project, to build A robotic arm. This project started out as a challenge put forward from one of his school teachers to build a robotic arm for $200. [VoR73X] accepted, and the challenge began.

He came up with a robotic arm that can be controlled from his mobile phone and other bluetooth enabled devices. He also designed it so that he can control it from the infrared remote control of an old tv set. [VoR73X] decided to kept the design simple, to make it easy for others to build. [VoR73X] has shared the code and a step by step process of how to build in the hopes that others would also like to take up the challenge. Watch the video after the break for further details on his project.

via[Instructables]

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