Raspberry Pi – Troubleshooting Flickering LED Strip

led stripraspberry piws2812b


I am following the adafruit for driving LEDs from the pi.

They suggest wiring it like this (this works great for me btw, no flickering):


This is how mine is wired:

my wiring

I'm sure some eyesores jump out at you:

  • wiring color
  • melted squares from when my ground and power were touching D:
  • hot glue around the peripheral wires
  • crossing wires at the power supply adapter

I drew a sharpie line on the wires that are ground.
When I wired it according to the guide, that is, with a breadboard that has vertical running lines for power and ground, it works great!

But moving it over to this mini breadboard it starts flickering.
I tried powering the led wires (circled in blue) with a wire that goes straight to the power supply adapter output (yellow wire), and it was a bit better, but not much.

So does the voltage really degrade that much with traveling across the board to my led strip connectors? Is the breadboard crap? Does having dedicated lines for power/ground make that big of a difference? Do I need a bigger power supply?

New wiring
New bread board helped a lot with wiring the power in parallel. I grounded the unused inputs to the level shifter. I added a 1000uf 16v capacitor although a smaller one would have been fine. Also added a resistor as recommended by Neopixel guide. I bought a multimeter and can see that voltage drop is much lower and there is almost no flicker.

The little led just shows when my external supply is plugged in.

Best Answer

These breadboard contacts are not intended to draw more than 1/4A so improve the connections with many more in parallel for V+, 0V.