some unexpected problems.

This was for under cabinet lighting in the kitchen. I had the idea to reuse the 14/2 wiring in the wall for the low voltage wire to the LED strips (I made my best effort to separate the wires used for low voltage from mains voltage, both with colored electrical tape and a 3d printed separator. You know, NEC codes and all...).

Basically, there were 3 sections of cabinets that I wanted to put LED strips. The one in the middle had the wire from the wall switch with mains voltage, so I put the 5V meanwell power supply and the controller (a D1 Mini ESP8266) there, and connected that to the LED strip in that section. Then I used the 14/2 wiring to the other 2 sections (not connected to anything else, obviously) for the LED strips in those places. I connected white to +5V, copper ground to ground, and then used black for the data signal to the LED strips. Because the wire runs went up into the attic to clear doorways, etc, they were long enough that I had to put a level shifter on the data signal from +3.3VDC to +5VDC. I just soldered this to a protoboard with the D1 Mini. With only those 3 wires (white, black, copper) in the wall, I decided to duplicate the data signal to all sections, so they are all just connected together. They all just duplicate each other running the same effects.

The end results? It works. Mostly. I was most worried about the section farthest from the controller because of voltage drop or data signal attenuation, so I did that one first, and it worked great. Not too much voltage drop, data signal looked good- the lights look good! But then I wired up the 3rd and last section, and the data signal was no good there so the LEDs were just flashing crazy colors. Strange since this section was supposedly closer to the controller than that other one that was working. I tinkered around for a while just to make sure I didn't have a bad connection on one of the ends, and I finally discovered that if I connected the LEDs directly to the 14/2 wire coming out of the wall, it worked. But when I added on the ~18" of wire (I used #18) to reach the edge of the LED strip, it couldn't handle that last length. No idea why. After trying several things, I finally added a sacrificial pixel right at the end of the 14/2 wire and then connected that to the wires that reached the end of the LED strip (so this sacrificial pixel is 18" from the end of the wire- definitely not your typical usage!). That worked, even though its kludgy as heck.

But I've also noticed that the data signal to all 3 sections isn't perfect. Most of the time I have the lights on a solid color with no animations, but every 1-2 minutes, the lights briefly flicker to a different color. That could also be related to why I struggled with that last section of LEDs.

I think the level shifter I am using might be too cheap, so my data signal is just marginal to begin with and can't handle much. My next step is to try replacing that level shifter with a nicer one rather than the one I bought on amazon for just $8 for a pack of 10. Thats not an urgent fix though.