# External Compass won't calibrate

**URL:** <https://discuss.px4.io/t/external-compass-wont-calibrate/15325>\
**Category:** Pixhawk\
**Created:** [February 23, 2020, 12:02pm UTC](https://discuss.px4.io/t/external-compass-wont-calibrate/15325 "2020-02-23T12:02:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Anselme](https://discuss.px4.io/user_avatar/discuss.px4.io/anselme/32/4788_2.png) [@Anselme](https://discuss.px4.io/u/Anselme)\
**Post date:** [February 23, 2020, 12:02pm UTC](https://discuss.px4.io/t/external-compass-wont-calibrate/15325/1 "2020-02-23T12:02:14Z")

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Hello,

I am trying to calibrate my external compass (which is a module containing a Ublox GPS and a compass) but it won’t work.  
I tried on MissionPlanner, but when the calibration bar reaches the end, the Pixhawk makes a fail sound and the calibration starts again.  
Then I tried with QGroundControl and I got a more precise error :

mag(0) bad radius 601 expected 479.

I searched on the web but it seems like there is no forums talking about that issue.

What can be the problem ? Is my compass broken ?  
My module is not near power cables (closest one is like 4 inch) and I am calibrating in the middle of the room with no magnetic interference.

What can I do to solve my problem ?

Thank you. Anselme

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**Author:** ![danielhellin](https://discuss.px4.io/user_avatar/discuss.px4.io/danielhellin/32/5541_2.png) [@danielhellin](https://discuss.px4.io/u/danielhellin)\
**Post date:** [February 24, 2020, 3:18pm UTC](https://discuss.px4.io/t/external-compass-wont-calibrate/15325/2 "2020-02-24T15:18:53Z")

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Check COMPASS\_ORIENTx parameter, maybe is wrong

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<div class="post-metadata">

**Author:** ![Anselme](https://discuss.px4.io/user_avatar/discuss.px4.io/anselme/32/4788_2.png) [@Anselme](https://discuss.px4.io/u/Anselme)\
**Post date:** [February 24, 2020, 5:26pm UTC](https://discuss.px4.io/t/external-compass-wont-calibrate/15325/3 "2020-02-24T17:26:48Z")

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Thanks for the answer but I already checked that. Tried with another compass and it works better… But it’s surely a Pixhawk problem since the sphere was good.  
I got a “Mag(0) bad radius 605 expected 479”…

No documentation talks about that on QGroundControl.

Thanks anyway