I’m working with a Fastrack Xtend, using GPIOs 21 and 25 on the 10 pin power supply connector as inputs. The documentation doesn’t appear to make it particularly clear what the GPIO input voltages should be i.e. what constitutes logic 0 and logic 1 voltage levels, what the maximum input voltage level is, how the input voltage relates to Vref etc. Am I missing something in the documentation? Does anyone have any experience with this that they can share?
A related portion of Fastrack Xtend User Guide rev 2 follows: