WS2812B LED strip with Arduino Uno R3

Wiring for the WS2812B addressable LED strip on the Arduino Uno R3 (ATmega328P, 5 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

WS2812B LED strip pin	Role	Arduino Uno R3 pin	Notes
5V	Power	5V	Use 5V for a few LEDs; a separate 5 V supply for more (up to 60 mA per LED)
DIN	Input to the part	2 (PD2)	Data in. Add a 330 Ω resistor; a 3.3 V to 5 V level shifter makes it reliable
GND	Ground	GND

Check before you power it on

Supply: 5 V from the 5V pin.
Motors, servos, relays and LED strips can draw more current than the Arduino Uno R3’s pins or USB can give. Power them separately and connect the grounds together.

Test code (Arduino)

// Library: Adafruit NeoPixel
#include <Adafruit_NeoPixel.h>

Adafruit_NeoPixel strip(8, 2, NEO_GRB + NEO_KHZ800);  // 8 LEDs

void setup() {
  strip.begin();
  strip.setBrightness(40);  // keep it low when powered from USB
}

void loop() {
  for (int i = 0; i < strip.numPixels(); i++) {
    strip.clear();
    strip.setPixelColor(i, strip.Color(0, 80, 255));
    strip.show();
    delay(100);
  }
}

Arduino board: arduino:avr:uno.

Questions

Which Arduino Uno R3 pins do I use for the WS2812B LED strip?

5V → 5V, DIN → 2 (PD2), GND → GND.

Does the WS2812B LED strip work with the Arduino Uno R3 at 5 V?

Yes: the WS2812B LED strip runs at 5 V and the Arduino Uno R3 uses 5 V signals, so no level shifting is needed.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full Arduino Uno R3 pinout · WS2812B addressable LED strip: all pins and data

The WS2812B LED strip on other boards

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