Reddit reviews Ginsco 530 Pcs 2:1 Heat Shrink Tubing Tube Sleeving Wrap Cable Wire 5 Color 8 Size with Storage Case

You'll want to connect them to each other like this.

You could solder them directly together, but I'd suggest using wires between them; solder one of the wire to one board, and the other side of the wire to the other board.

You could use electrical tape over the solder junctions to insulate them (instead of heat shrink), but make sure you wind the tape snugly and use at least 3 layers of tape around each junction. Here's an example kit of heat shrink. It's not expensive, and is rather easy to use. video of how to use shrink tube. Video on using a hair dryer in case you don't have a heat gun. If you don't have a heat gun or hair dryer, then heat shrink probably isn't a good option for you at this time.

For the capacitor and the wiring connections, don't follow the diagram verbatim. If one wire touches a bunch of other wires, it doesn't matter WHERE they touch, only THAT they touch. So, in theory, you could have one long "main" wire and solder other wires onto it separately one at a time along the entire length of the "main" wire, or you could just wire the ends of all the wires at one single spot, or "junction". Either way has the same effect - all the wires are ultimately touching. See how the capacitor is connected to the red and black wires? You could solder it at any point on either of those wires. So it could go right on top of the end of the neopixel strand, or right on top of the arduino, anywhere that you think would work well for how you're assembling this thing. If you're using a breadboard (i suggest this) and want the easiest option, you could plug it right into there and not worry having to actually solder it to anything. If you want a "best practices" opinion, it would be ideal to solder it right into the end of the neopixel strand.

Since you're using multiple neopixel strands, It might be best to use one of these capacitors in between each strand in a similar fashion. I'm not sure how much this would actually matter, though. Just kind of a safe vs sorry thing, I guess. One capacitor is probably fine.

By the way, on my diagram, I used pins 6 and 11 as examples. You can use any pin with an "A" (A0 thorugh A7) for the potentiometer, any PWM pin (3, 5, 6, 9, 10, or 11) for the neopixel output, and any pin with a "normal" number (2 through 13) for the pushbutton. Info on arduino pins.


More info on Arduino Pro pins, etc