Two Shift Registers running the same routine?

I’m certain its doable but what I’m looking to do to save pins utilizing shift registers in one project. The only problem is I need them to run the same routine at the same time. I can’t run wires very easily between LEDs for this without doing way too much “trenching”. It’s going to be bad enough with two shift register pins grounded plus the latch, clock and data pin wires. My code works but I only have one register right now so I can’t really test it. (Starter kit had only one). My thinking is simply duplicating the code with different variables but I’m not certain that works. Still this isn’t exactly about the code. Its more wondering how it’s done and how to do it (and if possible not using the 3 more pins I think I need).

Background: I’m looking to run 6 1.8mm LEDs (total of 12) on either side of this project about 12cm apart. Inside of each side is going to be a proto board with a shift register to control the 6 there to limit wires. But lets number the LEDs on the Left as 1 through 6 and on Right 1-6 with L meaning Left and R Right. When L1 and L4 are lit, I need R1 and R4 lit, then L2 and L5, R2 and R5, L3 and L6, R3 and R6 and then repeat. As of now I know I can get at least one to run but how to wire two shift registers to run in tandem. is it actually doable as I’m looking at it? Or should I look into programming a dedicated ATMega328 to run it? Finally if I do that, am I able to “take” over the chip functions with a button press to make them flash and flicker at random?

That's simple as simple can be. Take all the wires that go to the shift register you have now, connect wires from the same pins on the other shift register to the same pins on the Arduino. Now both shift registers get the same signals at the same time. You can't do two different things with them in this arrangement, but that doesn't sound like an issue for you. If you just want them to mirror each other then simply tie them to the same pins on Arduino and you don't have to change anything in the code.

Ok for the sake of example I’ll use my code. I’m utilizing pins 8,11 and 12 to go to the register I have. If I add Register2, just run from the same pins to Reg2?

santiago82:
Ok for the sake of example I’ll use my code. I’m utilizing pins 8,11 and 12 to go to the register I have. If I add Register2, just run from the same pins to Reg2?

That is exactly what I said. Run the second register to the same pins. Naming which pins they are doesn’t change that. Why do I need to repeat it?

<<slight comprehension problem. Sorry.