Category Archives: projects

MVVM and Speech using the Kinect-Pt. II

In the last post I talked about what I recently done with Speech recognition and tying it in with MVVM’s concepts of Commands.

In this post, I want to walkthrough, step by step of how I set things up.  To get everything installed I just followed the directions for setting up the Kinect SDK, which also included the direction on setting up the Speech API.  Google that and you’ll be well on your way.

After getting it setup, I recommend you give the Kinect SDK samples a try to make sure everything installed correctly.  From there I took a look at what the Kinect speech sample was doing and modified it to work with the default audio source instead of the Kinect.  Mostly, because my Kinect needs to pull double duty between my hacking and actually letting me play on the Xbox.  Not sure how I can convince the wife we need a second one just yet.

Note that some of the code examples use some extensions methods in a little library of mine.  So you might not be able to directly copy/paste. Hit up the continue reading link for the rest…

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Wii Remote Force Calculator

Recently, I’ve been doing a fun side project.  It’s always fun when you can come up with an excuse to combine your hobbies or interests.   So I came up with the idea of using a Wii remote to calculate the force of a strike on a heavy bag.

Screenshot

I’ve had to dredge up old memories from my college physics classes, and I’m not entirely sure what I’ve got is hundred percent accurate, but I feel with proper setup it’s pretty good.  The calculation is easy enough, to get the force you just multiply the mass times the acceleration of the object.  The accelerometers in the Wii remote are accurate to about  +/- 3 Gs with about a ten percent range of error.  Not too terrible for a fifty dollar bluetooth enable accelerometer you can pick up at any store in town.  The problem is, if you try to hold it in your hand you can generate massive amounts of acceleration well above 3 Gs.  So instead,  I tied the remote onto a heavy bag.  Much more mass, means you get the same amount of force with acceleration levels well within the remotes acceptable range.

Force = mass * acceleration

Because I’m not punching any harder, the force stays the same.  The heavy bag has a lot more mass, so the acceleration has to be a lot less to equal the same force.

The thing I’m not sure of is whether I have to take into account the fact the bag is on a chain so it actually swings up in an arc.  I don’t know how much that affects the calculations, but I don’t think it would be a lot with the small amount of time range we’re talking about.

My next steps are to try and rig up some testing system to try to determine the accuracy of the measurements.  I also want to get the opinion of some physics people to get my calculations even more accurate.  It’s been a fun project so far and I’d like to get it to the point where I could bring it into the gym and have my students play around with it a little bit.

The application itself is written in C#, using WPF, MVVM, and Wiimote Lib

I’ll try to post any updates here as they develop.