MotionFit Z-axis rotation reversal

By gruber , 1 August 2013
Forums
SmartMotion® MEMS Motion Sensors

When running eMPL-client.py, I observed a reverse rotation around the z axis, that is, on a flat table, rotating counter-clockwise caused the rectangle to rotate clockwise and vice versa. This was independent of whether the MotionFit card was facing up or down.

thanks

gruber

12 years 7 months ago

The reversal of axis appears using the python program eMPL-client.py.

The C++ program TeaPot, does not work. I have found the reason why and corrected it. (TeaPot was parsing a different packet than was being provided from MotionFit board. Upon running, TeaPot does not reverse the axis.

Problem must then be in the Python PyGame orientation.

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guy_mcilroy

12 years 7 months ago

You should be able to edit the python application to correct for the orientation change. There typically is a "mounting matrix" which reflects which side of the board the sensor is mounted, which can just flip the axes around to correct this. We'll be sure to verify this in the next release.

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grim

12 years 6 months ago

rferraro wrote: "The C++ program Tea Pot does not work".
It would be neat if you could share the Tea Pot fix. (I have MS Visual Studio 2010 Express installed - I assume I could recompile?).

This post caught my attention because I am trying to learn what PC applications work with the current versions of the MPU9150 for preliminary assessment before investing in more tools and moving on to code development. In that case, what version of CSS works with current Motion Fit 5.1 SDK hardware?

Thanks

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guy_mcilroy

12 years 6 months ago

When using the MotionFit board you must run the Teapot app included in the MotionFit zip file, trying to run an alternate Teapot app you will find it is not compatible with that board.

The Universal Datalogger is the PC app you should use for preliminary evaluation. Also our Embedded MotionDriver project includes a Python client that you can use for printing data.

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grim

12 years 6 months ago

Well, the C++ Program TeaPot.exe (9/21/12 file date) as found in the MotionFit.zip download does not work for me either.

Your response implies that this application does work. Can you please explain this contradiction? :? The device was discovered by Win XP Bluetooth and set up on COM6 but the application launches and does nothing and leaves the blue light permanently lit and the red light flickering. What could be the problem?

UDL does not provide real-time plots or operate with the SDK and PC Demo which does provide plots, does not support current MPU9150 devices (per your response in the Technical section). :( I am reluctant to wade into yet a third attempt to get working software with a python installation until I get your explanation for my second strike out.

Thanks for your patience with this.

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grim

12 years 6 months ago

Aha -you were right-- it was a Bluetooth setup problem ! The user guide uses a Win7 procedure which is sufficiently different than XP that a first time Bluetooth user can be confused into thinking a proper connection has been made. A little experimentation was motivated after the Python also failed and now I have both C++ and Python motion apps working. Cool ! 8-)

This does restore my confidence in the PC apps. One thing though, I never saw the blue light go out, but the Tea Pot display is very stable. I have been watching it for over 10 minutes ??

Now back to getting real time plots without PC Demo....any suggestions for my E series MPU-9150?

Thanks.

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