Mag calibration procedure and compass rose blink

[lucamacs]

Hello,
I have made some search on the forum but found only partial informations so ...

Can someone explain the exact calibration procedure for the mag and how to check that the compass is properly calibrated ?

What means when the compass rose blinks ?

Thank you !

[Alexinparis]

Once you click on the MAG calibration button, the LED will begin to flash rapidly for 30s.
During this time, you must orient the multi manually in all possible directions.
(Imagine you are inside a sphere, and you try to paint all the surface inside)

Once the LED stops flashing, the calibration is over.

If this step is correctly done, the MAG should be reasonably well calibrated.
We can imagine a more elaborated procedure like, but proceeding this way is enough for GPS use of MAG mode.

[lucamacs]

Thank you for the explanation Alex !
So if I understand well the Mag calibration is not crucial for GPS operation and there is no need of a strict control of it.

What does it means when the compass rose blinks ?

[Hogster]

I've been following the guide in the first post of this thread when calibrating:

viewtopic.php?f=8&t=1387&p=10658

Seems a more controlled way of calibrating than just rotating it to point in as many directions as possible ... I could be mistaken though!

I'm not sure what the blinking indicates I'm afraid ...

David

PS. I'm currently struggling with a problem where the magnetometer values freeze after a random period of time, and only reloading the software (rebooting the GUI) gets them moving again. I'm not getting any I2C errors and there's nothing which triggers the values to freeze. Sometimes it will freeze <30 seconds after startup, other times it can sit there perfectly happily for 10 minutes before freezing. But I don't trust the mag enough yet to go flying with it ...

[lucamacs]

....
PS. I'm currently struggling with a problem where the magnetometer values freeze after a random period of time, and only reloading the software (rebooting the GUI) gets them moving again. I'm not getting any I2C errors and there's nothing which triggers the values to freeze. Sometimes it will freeze <30 seconds after startup, other times it can sit there perfectly happily for 10 minutes before freezing. But I don't trust the mag enough yet to go flying with it ...

Weird , only Mag values freeze ?

[Hogster]

Hi lucamacs,

Yes, it's very odd ... I've got a replacement FreeIMU (0.4.3) on the way which I will drop in place of the current one to see if it's a faulty magnetometer or not. I've tried resoldering the wires going from the FreeIMU to the sensor board, but still no joy (thought it might have been a dry solder joint).

Will let you know if the replacement suffers from the same problem!

Cheers,


David

[Alexinparis]

I'm not sure what the blinking indicates I'm afraid ...

It just indicates a 30s timer. Nothing more.
After 30s, the blink stops, and the calibration is based on the MIN/MAX values recorded for each axis during this time.

[lucamacs]

Alex, we were talking about the compass rose ring blinking in the Gui not the led blinking .

Can you tell us what is the meanng of the compass rose ring blinking ?

Thanks !

[Alexinparis]

Alex, we were talking about the compass rose ring blinking in the Gui not the led blinking .

Can you tell us what is the meanng of the compass rose ring blinking ?

Thanks !

The compass rose blinks when a GPS frame is received, indicating a fine connection with a GPS device (with or without 3D fix)
Is is not tied to MAG.

[lucamacs]

Merci beaucoup !