I am looking at using the 74HCT164 in a future project and I was curious as to how I would have it use a clock? A lot of its serial input is entered in when the clock is on its rising edge. I've always used chips that have examples for them, and they took care of the clock in the programming with an external library. Now that i'm coming up with my own program, I figure I need to know how to do that. How would I make the arduino constantly send a square wave clock?