Yes, sorry.. I think I should be more precise about what I said… What I should’ve said is that I believe under normal operation of input/output duties it should perform ok, BUT if you’re using an external time/clock module such as the DS1307x and I assume the DS3231 module, expect this CLOCK signal to be interrupted automatically by the default setting of the Arduino on both or either, PIN2 & PIN3.
To power or provide HIGH/LOW signals on the pins is absolutely fine or for that matter to use as INPUTS. You really have to understand the logic of the interrupts to realise why it will impede/halt the EXTERNAL clock signals and point to an error related solution as the functions kind of proceed on a FIFO principle, as there isn’t multithreading capabilities… so a bit of a back-pedal for me as I’m used to taking advantage of multithreading lol.
Thanks for the reply Cattledog, as I said above… If you HAVE to use an external Clock module and HAVE to use either PINS 2 or 3 as inputs, then yes Interrupts will have to be disabled, and that can come at a price depending on your project.
Good luck all!!