kwatters's blog

Center-tap pot and the oscope

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I've tried connecting up the center tap of the servo pot to an analog input of the arduino and measured it with the oscope of MRL.  fun...


here's some images of the with and without the ground line connected.. i'll leave it up to you to see which is which.  (I was manually turning the pot myself.. watching what happened on the analog input pin 0 of the arduino that i connected up...)


D-H Parameters and the InMoov for a Kinematic Model

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Update:   I'm kinda geekin' out about this right now...  It looks like all those matrix multiplications do something useful...



Did a quick simulation with MRPT of what I believe is a resonable approximation of the InMoov arm.



Closing the Loop on Hobby Servos with MRL

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This is really a page to talk about how to measure the actual angle that a servo has reached, rather than the last position the servo was told to move to.  The aim is to be able to allow the servos to automatically configure their actual max/min angles.  In addition, it should allow for quicker response to the stop() method.

The stop() method stops the sweeper that is currently running for the servo.  However, this only tells it to stop the sweeper, the servo will continue to move to the last position it was told to go to.

Using OpenSCAD to edit STL files

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Here's a simple example of how to use OpenSCAD to edit a pre-existing STL file.  This is useful if you want to add or subtract areas to the existing file.  

OpenSCAD is an open source CAD program that allows users to programmatically build up models using basic geometries.  The below example is based off of the part 

Download OpenSCAD from   (It's free)

Download the STL file that you want to edit. For this example I used


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Lets figure out how we can control InMoov & mobile platforms with the Xbox (and other controllers)

ProgramAB , AIML and MRL Support for OOB tags.

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This page is Work in Progress


AIML supports OOB tags in the response from ProgramAB.

There is not a strict definition of what OOB tags are.  For more info take a look at

OOB tags are usually something like   <search>foo</search>

Python file object

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Here's some examples of reading and writing files in python,  Thought it might be useful for some.