Overview

The ws2812 node controls WS2812 (NeoPixel) addressable RGB LED strips, allowing individual pixel color control, fill patterns, rainbow animations, and brightness adjustment. Each LED in the strip can be independently set to any 24-bit color (or 32-bit with RGBW strips), enabling rich visual feedback, status indicators, ambient lighting, and dynamic light shows for IoT dashboards and smart environments.

16M

Colors (24-bit)

800kHz

Data Rate

LED Voltage

60mA

Per LED (max)

Properties

Property	Type	Required	Default	Description
pin	number	Yes	18	Data GPIO pin (must be PWM-capable, BCM numbering)
ledCount	number	Yes	8	Number of LEDs in the strip
brightness	number	No	255	Global brightness level (0-255)
stripType	select	No	"GRB"	Color order: "RGB", "GRB", "RGBW", or "GRBW"
frequency	number	No	800000	Signal frequency in Hz (800kHz for WS2812B)

Inputs

msg.payload

Object with action and color parameters.

{
  "action": "fill",
  "color": "#FF0000"
}

"fill" Fill all LEDs with one color

"set" Set a specific LED (requires led index)

"rainbow" Apply rainbow gradient across strip

"clear" Turn off all LEDs

Outputs

Strip State

Outputs current strip state and action confirmation.

{
  "ledCount": 8,
  "brightness": 255,
  "action": "fill",
  "timestamp": 1709251200000
}

Input Format Details

Fill All LEDs

{
  "action": "fill",
  "color": "#00FF00"
}

Set Single LED

{
  "action": "set",
  "led": 3,
  "color": "#0000FF"
}

Set Multiple LEDs

{
  "action": "set",
  "colors": [
    "#FF0000", "#00FF00",
    "#0000FF", "#FFFF00",
    "#FF00FF", "#00FFFF",
    "#FFFFFF", "#000000"
  ]
}

Rainbow Pattern

{
  "action": "rainbow"
}

Wiring / Connection Diagram

WS2812 LED Strip to Raspberry Pi

  Raspberry Pi                    WS2812 LED Strip
  +-----------+                  +--[LED0]--[LED1]--[LED2]-- ... --[LEDn]--+
  |           |    330Ω          |                                         |
  |  GPIO 18  |---[Resistor]-----| DIN (Data In)                          |
  |           |                  |                                         |
  |  GND      |---[Ground]-------| GND                           GND      |
  |           |                  +------------------------------------------+
  +-----------+                        |                             |
                                       |                             |
   External 5V Supply                  |                             |
   +----------+                        |                             |
   | 5V  (+)  |------------------------+ VCC                        |
   | GND (-)  |------------------------+ GND                        |
   +----------+                                                DOUT (unused
                                                               or to next strip)
  Power Calculation:
  Each LED draws up to 60mA at full white
  8 LEDs = 480mA max, 60 LEDs = 3.6A max
  Always size your power supply accordingly!

Important: Use a 330 ohm resistor on the data line. Add a 1000uF capacitor across the power supply. For long strips (60+ LEDs), inject power at multiple points to prevent voltage drop.

Example Use Cases

Temperature Status Indicator

Map temperature readings to a color gradient on the LED strip (blue=cold, green=normal, red=hot).

dht22 → function → ws2812

[
  {
    "id": "temp-sensor",
    "type": "dht22",
    "pin": 4,
    "interval": 5000
  },
  {
    "id": "temp-to-color",
    "type": "function",
    "func": "var temp = msg.payload.temperature;
var color;
if (temp < 18) color = '#0000FF';
else if (temp < 25) color = '#00FF00';
else if (temp < 30) color = '#FFAA00';
else color = '#FF0000';
msg.payload = { action: 'fill', color: color };
return msg;"
  },
  {
    "id": "status-strip",
    "type": "ws2812",
    "pin": 18,
    "ledCount": 8,
    "brightness": 128,
    "stripType": "GRB"
  }
]

Dashboard Color Picker Control

Use a color picker widget on the dashboard to set LED strip color in real time.

color-picker → change → ws2812

[
  {
    "id": "picker",
    "type": "color-picker",
    "label": "LED Color"
  },
  {
    "id": "format-cmd",
    "type": "change",
    "rules": [
      {
        "t": "set",
        "p": "payload",
        "to": "{ "action": "fill", "color": payload }",
        "tot": "jsonata"
      }
    ]
  },
  {
    "id": "led-strip",
    "type": "ws2812",
    "pin": 18,
    "ledCount": 30,
    "brightness": 200,
    "stripType": "GRB"
  }
]

MQTT-Controlled Ambient Lighting

Control LED strip colors and patterns remotely via MQTT from any connected device.

mqtt-in → ws2812

[
  {
    "id": "mqtt-leds",
    "type": "mqtt-in",
    "topic": "home/livingroom/leds",
    "datatype": "json"
  },
  {
    "id": "ambient-strip",
    "type": "ws2812",
    "pin": 18,
    "ledCount": 60,
    "brightness": 255,
    "stripType": "GRB",
    "frequency": 800000
  }
]

// MQTT payload examples:
// Fill:    { "action": "fill", "color": "#FF6600" }
// Rainbow: { "action": "rainbow" }
// Clear:   { "action": "clear" }
// Single:  { "action": "set", "led": 0, "color": "#FFFFFF" }

Common Use Cases

Ambient Lighting

Smart room and under-cabinet lighting control

Status Visualization

Visual bar graphs for sensor data and system health

Alert Indicators

Color-coded warnings for thresholds and alarms

Interactive Displays

Light shows, progress bars, and notification strips

Related Nodes

buzzer

Audio alerts and tones

relay

High-power load switching

gpio-out

Direct digital output pin control