wow thanks for the quick replies! 
I will quickly read that thread and will go through in more detail tonight - I'm guessing the for loop isn't the best method for sequencing and I should be looking at if statements or switch/case?
I've just read that there is clock_t for c++ that deals with time, does anyone have experience with this?
More info on what I want to practice - basic 8 step sequence that outputs gate/trig signals with a tempo control. each step will have a button thats an ON/OFF to output the gate/trig.
I was looking at taking a pin out from an stm32 and converting it with the logic level converter to 5v.
Is it more sensible to use c code rather than c++ ?
thanks,
P