Walking Motion Analysis Using Wii Remotes

March 1, 2011 by Mike Szczys 10 Comments

WiiGait is not a political scandal, it’s a project that records motion data while walking. [Bilal Chishti] and [Zassa Kavuma] are strapping a Wii remote onto each leg and recording the sensor data while making video of the walker at the same time. The two are using an Ubuntu box to pull the sensor data from the Bluetooth-enabled devices and utilizing its built-in webcam for the video. They graph the data for each axis and we’re sure that syncing up data anomalies with the video is just a matter of matching timestamps.

So what good is this? The creators are keeping us in the dark about an end-goal for collected data; this may just be for the experience of using the hardware. But we could see it having uses in making distance runners more efficient, or teaching that bipedal robot how to balance.

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Paper Accelerometers For Pennies In The Works

February 12, 2011 by Mike Szczys 20 Comments

Cheap paper accelerometers? Put us down for a dozen to start. They’re not quite ready for mass production yet but it looks like they’re on the way.

[George Whitesides] led a team to develop the new technology that uses simple manufacturing methods to produce the sensor seen above. Graphite and silver inks were screen printed onto heavy paper. The single limb sticking out from the body of the sensor is a separate piece of paper that bends the carbon area when force is applied. This changes the carbon’s resistance which is measured using a Wheatstone bridge constructed by gluing resistors to the device.

It sounds unsophisticated compared to most of the accelerometer modules we’re used to, but if you need a sensor that detects sudden motion this sounds like the perfect part. Now who wants to be the first person to replicate this in their basement?

[Thanks Fabien]

Amarino Makes Android Controlled Robots A Snap

January 24, 2011 by Mike Szczys 5 Comments

[Lucas Fragomeni] is controlling this robot using the accelerometer on his Android phone (translated). He could have gone through our Android tutorials and developed a custom application but he took the shorter route and used Amarino, an ‘Android meets Arduino’ toolkit, to do it for him. [Lucas] combined an Arduino, a BlueSMiRF Bluetooth modem, and two servo motors to build his robot. Amarino lets him connect to that Bluetooth modem and send sensor data over the connection. In this case it’s only the accelerometer that he chose to use, but he could have gone with the touchscreen, or any other sensor the handheld has to offer. Using this code package got him up and running quickly, only requiring that he writes his own code to turn the received signals into servo motor control routines. See it in action after the break.

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Data Logging Football

January 9, 2011 by Mike Szczys 6 Comments

[Ben Kokes] threw together a hardware package to capture data from a football. In the center of a Nerf football he made room for an accelerometer, gyroscope, and an electronic compass. All three can capture 3-axis data and, along with the LEDs ringing the circumference, they’ve controlled by an XMEGA192 microcontroller.

This makes us think back to a time when baseballs with a built-in speed sensor first hit the market… does this hack have mass marketing potential? Perhaps, but only if the $225 sensor price tag were greatly reduced. When we first started reading the description we hoped that [Ben] had coded an interpreter that would render 3D playback video from the data. He hasn’t done that, but from the data graphs he did assemble we don’t think that functionality is out of the question. We’ll keep our fingers crossed.

Hopefully Detect Trolls Before They Devour You

November 25, 2010 by Joseph Thibodeau 24 Comments

In the cold and mysterious wilderness of Norway, it pays to be ready for anything–especially heavy-walking trolls. The team at [nullohm] decided to prepare thoroughly for their trek into the woods to witness the Leonids meteor shower by putting together an Arduino-based “troll detector”.

The device is based on the superstition of hammering a steel spike into a tree to keep trolls away from camp. This goes one step further by including an accelerometer and LED indicators so that you can tell exactly what type of troll is just about to feast upon your tender human flesh.

When the detector is installed into a nearby tree, it takes an average seismic measurement and then looks for telltale footfalls. Even if you’re not concerned with perpetuating superstitions, you might find a use for the source code for simple seismic activity monitoring at home to supplement your miniature seismic reflector.

Gum Ball Maze Updated… Now With Robots!

November 11, 2010 by Mike Szczys 5 Comments

In what is surely becoming an ever-growing Rube Goldberg machine, [Dan] updated his gum ball dispenser to include a robot arm. We looked in on this human lab-rat experiment that rewards successful maze navigation with bubble-gum just about a year ago. As you can seen in the video after the break he’s added several new features to delight users. The original had a maze actuated by an accelerometer and that remains the same. But when the device fires up, the wooden ball is moved to the start of the maze by a Lynxmotion robotic arm. That arm is mounted on rails so it can also move to deliver the gum ball after a successful run. There’s also an anti-jamming feature that shakes the gum ball dispenser to ensure you don’t come up empty.

Whether playing chess or being controlled by a mouse the Lynxmotion has been quite popular lately. [Dan’s] solution uses a vacuum pump to grab onto the spheres (both wooden and gum), similar to the method used with the CNC pick and place from a while back.

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Easy Quadrotor Helicopter Instructions

September 8, 2010 by Mike Szczys 19 Comments

Here’s a great tutorial on building your own quadrotor helicopter. This build isn’t necessarily less expensive than others we’ve seen since quality motors, propellers, and control circuitry aren’t cheap. But the design and assembly is well documented and presents a well-planned building procedure. The carbon-fiber tubes that make up the frame have extensions to protect the motors and propellers in the event of a crash. The Arduino, IMU, and transceiver are all tucked away between two aluminum body plates as well. They only thing missing is a solid methodology for tuning the four motors, a critical procedure that is just touched up at the end of the article.