ShiftOut now working as expected

Using Arduino Programming Questions
#1

I am trying the ShftOut tutorial
https://www.arduino.cc/en/Tutorial/ShiftOut
I am using an Uno and I have the 74HC595 shift register.
I have built my circuit exactly the same as the example except I don't have the .1F cap installed. According to the tutorial, the cap is to eliminate flicker, so I don't think that is my problem.

What I am seeing when I run the program is that all of the LEDs flash at the same time. All on, all off, all on, all off. But every once in a while I do see a different pattern, but the next cycle it is back to all on or all off.

Any ideas what may be causing this? I have double checked the wiring and I think I got it right. And the code is just a copy and paste of the Hello World example on that page.

#2

Yeah, that cap isn't really optional. Add it in there and see what happens.

#3

Thanks!
They call for a .1''F capacitor. I'm used to dealing with uF and pF. What size do I really need?

#4

That must be a typo. In the diagram they have 1uF, which is a much more reasonable sounding value.

#5

Yeah, I agree. Thanks!

#6

Well, I got some electrolytic caps today, and I have tried all kids of sizes (.1uF to 10uF), still no joy. All I get is the entire row blinking all at once.

Is there an even simpler program than the hello world? I can't believe I just asked that. I don't have an o-scope to check things out, so that isn't an option.

#7

Actually, never mind. I decided to try a different board (Mega) and it works. I think my Uno has issues.

#8