SparkFun Forums 

Where electronics enthusiasts find answers.

Questions &/or issues related to products in the Movement & IMU category should be posted in this forum.
By Mdbirley
#203647
I have an older 9 DOF and was thinking about buying your newer product. I read the hookup guide for the 14001 board and can not find much on calibrating the unit, especially for the magnetometer. Can you point me to the calibration procedure.
Can you also indicate what the desired (most likely) magnetic offsets would be. What usable magnet offsets could be and what makes the unit unusable for getting a +- 2 degree mag bearing.
Thanks
Max
User avatar
By TS-Chris
#203662
I read the hookup guide for the 14001 board and can not find much on calibrating the unit
The example firmware that comes with the 9DoF Razor IMU M0 does calibration automatically when power is applied. You do need to keep the board perfectly still for about 10 seconds for the auto calibration routine to work though.
Can you also indicate what the desired (most likely) magnetic offsets would be. What usable magnet offsets could be and what makes the unit unusable for getting a +- 2 degree mag bearing.
Unfortunately I don't have any more information on this but the data sheet might have what you're looking for though.
By Mdbirley
#203700
ok bought the board. Set it up. used the preloaded sketch. Then loaded the
SparkFun 9DoF Razor M0 Example Firmware
Jim Lindblom @ SparkFun Electronics
Original creation date: November 22, 2016
https://github.com/sparkfun/9DOF_Razor_IMU/Firmware

Powered up the board
left it still for 30 seconds and hey presto the heading is NOT indicating north. it is at least 45 degees off.
Printed on the board the mag and acc X are in different directions. I assume that north is oriented along the mag x direction

also should the board sit SD card up ie directions on x y down?

I assume that I do not need the SD card to be in the reader to get correct readings
By Mdbirley
#203701
What I left out of the conversation is that I am only interested in heading. I want to make sure that the magnetometer can be hard and soft iron calibrated and give a non drifting estimate of heading. If this IMU, libraries and code is not the best for a heading estimate can to point me to the best product that you sell.

I did load up the Quarternion sketch in the DMP library and that works reasonably well. At least the north was closer. For my purpose I need the best estimate of magnetic north I can get

regards
Max