Thanks Mike,
Looking at the schematic I believe you are correct. I would’t have guessed though without your help. The MicroMod general pinout table does not help here either. What would have been helpful would have been an SPI_CS table that gave:
SPI_CS# ; pin55 ; STM32 pinout label PC4 (reserved for microSD)
SPI_CS1#; pin 70 ; Not Connected; (In case one was mislead to thinking this could be used)
G0; pin 40 ; STM32 pinout label PD2; SPI_CS header available on PTH header.
My problem is now solved and the SPI magnetometer is working fine and logging nicely onto the SD card!!
Lockie