node-red-contrib-raspi5-neopixel 1.0.0

Raspberry Pi 5 WS2812 / NeoPixel pure JavaScript Node-RED node with SPI0/SPI1, selectable color order (RGB/GRB/...), brightness, per-pixel control and effects

npm install node-red-contrib-raspi5-neopixel

node-red-contrib-raspi5-neopixel

WS2812 / NeoPixel LED strip Node for Raspberry Pi 5 – pure JavaScript, no Python, no external daemon.

Supports:

• SPI0 and SPI1 (bus/device selectable)
• Selectable color order (GRB, RGB, BRG, BGR, RBG, GBR) – red is red on every strip model
• test command to find the right color order in seconds
• Global brightness (0–100 %) + optional gamma correction
• Fill, single pixel, range or one color per LED
• Colors as CSS name, hex, r,g,b, array or object
• Effects: rainbow, colorcycle, lava, blink, pulse, sparkle, chase
• Dynamic wiring hints in the Node-RED editor

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⚠️ Prerequisite: SPI must be enabled

This node talks directly to /dev/spidev*.
If SPI is not enabled, the node cannot work.

Enable SPI0 (standard)

sudo raspi-config

→ Interface Options → SPI → Enable

Reboot, then check:

ls -l /dev/spidev*

You should see at least:

/dev/spidev0.0

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Enable SPI1 (second SPI controller)

SPI1 is not enabled by default.

Edit:

sudo nano /boot/firmware/config.txt

Add one of the following lines:

dtoverlay=spi1-1cs

or (3 chip-selects):

dtoverlay=spi1-3cs

Reboot.

Verify:

ls -l /dev/spidev*

Expected:

/dev/spidev1.0

If /dev/spidev1.0 does not exist → SPI1 is not active.

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More than ~170 LEDs

The kernel limits one SPI transfer to 4096 bytes by default (≈ 170 LEDs).
The node shows an error with the exact numbers if your strip is too long.

Fix: add this to the end of the single line in /boot/firmware/cmdline.txt:

spidev.bufsiz=65536

Reboot and check:

cat /sys/module/spidev/parameters/bufsiz

65536 bytes ≈ 2700 LEDs.

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Wiring

The node editor shows dynamic wiring instructions depending on SPI0/SPI1 selection.

Only the MOSI pin is used as data line:

Bus	MOSI (→ LED DIN)
SPI0	GPIO10 (Pin 19)
SPI1	GPIO20 (Pin 38)

• GND Pi ↔ GND LED ↔ GND power supply (⚠️ common ground is mandatory)
• 5V LED from an external power supply (⚠️ never more than a few LEDs from the Pi 5V pin)
• ~60 mA per LED at full white
• Recommended: 330 Ω in series with DIN, 1000 µF across 5V/GND at the strip
• WS2812 expects 5V logic: short data wire (< 30 cm) or a 74AHCT125 / 74HCT245 level shifter

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Installation

Via Node-RED Palette

Search for:

node-red-contrib-raspi5-neopixel

Manual install

cd ~/.node-red
npm install node-red-contrib-raspi5-neopixel
sudo systemctl restart nodered

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Node Configuration

Configured entirely inside the node:

• SPI Bus (0 or 1)
• Device / CS (0–2)
• SPI speed (Hz, default 6400000)
• Number of LEDs
• Color order: GRB (most WS2812/WS2812B), RGB, BRG, BGR, RBG, GBR
• Brightness (%)
• Gamma correction
• Off on close (LEDs off on deploy / stop)

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Finding the right color order

Send:

msg.payload = "test"

• LED 0 must be red, LED 1 green, LED 2 blue
• Red and green swapped → switch between GRB and RGB
• Blue in the wrong place → try the other orders

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Input

Fill the whole strip

msg.payload = "red"            // CSS color name (148 names)
msg.payload = "#FF8000"        // hex, also "#F80" or "FF8000"
msg.payload = "255,128,0"      // also "rgb(255,128,0)"
msg.payload = [255, 128, 0]
msg.payload = { r: 255, g: 128, b: 0 }

Single pixel / range

msg.payload = "blue"
msg.pixel   = 4                // only LED 4

msg.payload = "green"
msg.start   = 10
msg.count   = 5                // LEDs 10..14

Other LEDs keep their color.

One color per LED

msg.payload = ["red", [0,255,0], "#0000FF", "off"]

LEDs not in the array are switched off.

Off

msg.payload = "off"            // also "clear" or "black"

Brightness

msg.brightness = 30            // 0..100 %, stays active

Can be sent alone (no payload) or together with a color.

Effects

msg.payload  = "pulse"
msg.color    = "orange"        // optional (blink, pulse, sparkle, chase)
msg.interval = 30              // optional, ms per frame

Effect	Description
rainbow	moving rainbow over the strip
colorcycle	whole strip cycles 7 colors
lava	red/orange flicker
blink	on/off (msg.color)
pulse	smooth fade in/out (msg.color)
sparkle	random twinkles (msg.color)
chase	one LED running along the strip (msg.color)

An effect runs until the next message.

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Output

No output. The node status shows the current state:

• green dot: ready / color
• blue dot: effect running
• yellow dot: test pattern
• grey ring: off
• red ring: error

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Examples

Menu → Import → Examples → node-red-contrib-raspi5-neopixel → basic

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Safety

• ❌ Never power long strips from the Pi 5V rail
• ❌ Never hot-plug a strip while powered
• ✅ Test with low brightness first

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Test / Debug

Check permissions:

groups
# user must be in group: spi

Add user if needed:

sudo usermod -aG spi $USER

Re-login required.

Wrong / flickering colors:

• wrong color order → use test
• missing common GND or weak power supply
• long data wire without level shifter

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Credits

Based on @tomsith/node-red-contrib-ws2812-pi5 by Tom Schmitz (MIT).

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License

MIT