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kriswiner / MPU9250

Arduino sketches for MPU9250 9DoF with AHRS sensor fusion
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quaternion convention #364

Open shomedas opened 5 years ago

shomedas commented 5 years ago

Hi Kris, What does quaternion q denote in your code? Is it the board frames orientation w.r.t. earth frame or vice versa. One of your comments in the code says it to be

quaternion-based estimate of absolute device orientation which means its the boards orientation wrt earth.

In madgwicks paper, it is earths frame wrt board.

I need to know it as I am need to use the same convention in rest of my own code.

kriswiner commented 5 years ago

These mean the same thing. The quaternions specify the absolute orientation of the board with respect to the Earth's frame. True North == q(1, 0, 0, 0).

On Thu, May 9, 2019 at 12:34 PM shomedas notifications@github.com wrote:

Hi Kris, What does quaternion q denote in your code? Is it the board frames orientation w.r.t. earth frame or vice versa. One of your comments in the code says it to be

quaternion-based estimate of absolute device orientation which means its the boards orientation wrt earth.

In madgwicks paper, it is earths frame wrt board.

I need to know it as I am need to use the same convention in rest of my own code.

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