STM32 on Nucleo64

Right. I didn’t know at the time it could simply work as the latter, with just a semi-colon.

Yes the NOP()s can be removed from there and a few more places.

I think I saw a video on an interrupt callback where an explicit NOP was used in the else of an if statement, so took the idea from there. I’ve since learnt that more common uses of NOP are for timing and synchronisation.