Addressable LEDs (WS2812)

Addressable LEDs such as the WS2812 (often called NeoPixels) let you set the colour and brightness of every LED in a strip, ring or matrix from a single data pin. That is what makes light shows, sound-reactive strips, clocks, timers and status rings possible with just one wire from your board.

Power is the part that catches people:

  • A WS2812 can draw up to about 60 mA per LED at full white.
  • A handful of LEDs can run from the Arduino's 5V pin for testing.
  • Longer strips need their own 5V supply, with ground shared back to the board.

For a reliable strip:

  • Add a resistor of a few hundred ohms in series with the data line.
  • Add a large capacitor across the strip's power input. That stops the first LED flickering or showing wrong colours.

How to choose:

  • Pick a strip for long runs.
  • Pick a ring for timers and gauges.
  • Pick a matrix for text and pixel art.

Ordinary LEDs are different. A plain LED needs a current-limiting resistor: supply voltage minus the LED's forward voltage, divided by the current you want.

WS2812 parts work with Arduino and ESP32 using common LED libraries.

Frequently asked questions

How much power does a WS2812 strip need?

Up to about 60 mA per LED at full white. Use a separate 5V supply for more than a few LEDs.

Why does the first LED flicker?

Usually a missing series resistor on the data line or a dipping supply. Add the resistor and a capacitor across power.

How many pins does a strip need?

One data pin, plus 5V and ground.

How do I size a resistor for a normal LED?

Subtract the LED's forward voltage from the supply, then divide by the current. Our 2-minute guide works through it.

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