In the following schematic you can see that
Q4 both are connected to a Arduino's Digital Input Pin. So if
Q1 is high and
Q4 is low, would there be current flowing from
Q4 (and through the chip) to Ground - or is there already some protection inside?
Are the output pins on the 74HC595 shift register protected from connected voltages in the realms of their own VCC? Or do you need to put a diode in?
I feel like this is a very basic question, which makes it very weird that I didn't find an answer to this, already... :-( Am I looking into the wrong resources? I had a look into the provided datasheet, but couldn't find any information. Didn't get any results from searching for existing posts on Stack Exchange or other sites.