Hi again Ben!
Further investigation: Suddently, while I was surfing concerning the HMC 5883 I found out that there are two different type, and I have both. ?
On the PCB on the one type I see printed: GY- 271 and on the other GY- 273 but should be the same HMC5883 so why ??
FC8. If I perform the test with the GY - 273 I get the value -1 on X,Y,Z.
FC8. If I test the GY - 271 I get some random number when powering the Arduino up, and then it stop, nothing more happend.
I make a test from here with Arduino IDE "stolen" from here

:
https://www.instructables.com/id/Tutori ... duino-Uno/
With the GY-271 It work in Arduino IDE. But not with the GY - 273.??? For me, I would be glad if only one of them work in FC8.
(But I want in FC8 for implementing in a another project)
Maybe this help.
Br Jorgen