Update stand-alone examples - to fix no Magnetometer values for test sketch OLA_IMU_Basic_Standadlone.ino

[starrobin34]

Hello Sparkfun Team,

with the OLA_IMU_Basic_Standadlone.ino everything seems to be working fine, except I am not getting any values for the Magnetometer. I haven't changed anything but I've tried examples from ICM_20948.h and I am getting the same result. My board is the OLA V1 (redboard) with IMU. Set up in Arduino IDE as "RedBoard Artemis ATP"

IMU ouput:
Scaled. Acc (mg) [ 00181.64, -00090.82, -00979.98 ], Gyr (DPS) [ -00000.33, -00000.66, -00000.42 ], Mag (uT) [ 00000.00, 00000.00, 00000.00 ], Tmp (C) [ 00030.14 ]

Appreciate help, let me know if you need further information.

Edit 1: wollewald/ICM20948_WE#7 seems to be the same issue
Edit 2: I just downgraded the Sparkfun ICM_20948 library to 1.2.8 and now the magnetometer works

[PaulZC]

Hi @starrobin34 ,

I think the explanation is that the stand-alone examples are out of date compared to the Apollo3 core. The OLA firmware uses the latest version of the 20948 library (1.3.0) and a special patched version of Apollo3 2.2.1. The stand-alone examples were tested using 2.1.0 of Apollo3 and haven't been touched since... Back then (August 2021) the 20948 library would have been at version 1.2.7. I suspect something changed as we moved both the Apollo3 core and the 20948 library forward.

I will leave this open as a reminder to update the stand-alone examples to match both the Apollo3 core and the 20948 library. No promises on when I'll be able to do this. It could be weeks, months or never... Sorry!

Best wishes,
Paul

[starrobin34]

Hey Paul,

all good I can work with the old version! Thanks for the quick reply
Cheers Robin

[PaulZC]

Hi Robin (@starrobin34 ),

Also, please check that you do not have the DMP enabled in the 20948 library when running the OLA_IMU_Basics sketch. The magnetometer needs to be configured differently when using the DMP, so the IMU begin terminates early leaving it to other code to finish configuring the mag. Maybe you had the DMP enabled in a recent version of the 20948 library, and regressing to 1.2.8 disabled it?

I hope this helps,
Paul

[starrobin34]

Yes, I looked into that. In the latest version of the library, it's commented out by default. I think the issue lies somewhere here though.