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Topic: HMC5883 Magnetometer - confusion with axis orientation  (Read 99 times) previous topic - next topic

guillenvar_2

Hi all, I'm confused with the axis drawn in the board ( GY-273 )  and the relation with the output data for each one, for example, I thought that the axis drawn were vectors, so the output data for the axis that would point the north is at his maximum positive value, and if that axis points oposite to north would be at his maximum negative value, and the transition between the positive and negative would be from its maximum positive to cero to maximum negative ( e.g. +270 -> 100 -> 0 -> -100 -> -270), all transition between signs has to cross cero, but the behavior that I'm seeing is:

- If I point the X axis to the north I get the maximum positive value, If I rotate the sensor a little counterclockwise the output decreases as expected, but If I rotate the sensor clockwise the output jumps instantly from the maximun positive value to the maximum negative value, like pointing it oposite to north, but I'm just rotating it like 2 degrees counter wise from its maximum positive value, so that is not like a vector behavior, what i think is that the sign describes something related to a positive or negative declination that are related to the north, but I don't really know what the sign tells me or what the output is, I discarded that behavior due to something related with the place where I'm testing it, if that would be the cause, any compass would not work (the compass from my phone works well) so I don't think that is related with something like the room where I am , I'm not using any library.

Any ideas what the data describes?

Thank you in advance for your help.

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