LED strips and fire

Addressable LED strips are the quickest way to make a prop look alive: glowing eyes, a lantern that flickers, a cauldron that bubbles green.

Not yet tested on a real strip

The strip driver was rewritten in October 2026, and the clocked-strip support and the fire effect are new. None of the three has been run on a real strip yet, only on the bench without one. If your strip stays dark or shows the wrong colors, please report it with the strip type and board.

Which strip?

Strip	Wires to the board	Console function
WS2812B (often sold as “NeoPixel”)	one data wire	LED strip (WS2812)
SK9822 or APA102 (“DotStar”)	data and clock	LED strip (SK9822 / APA102, clocked)

Either kind works. WS2812 is cheaper and easier to find. The clocked kind is more forgiving about timing and long wires. Each board page says how many strips it can run. The DevKit V1 can run up to 8 WS2812 strips.

Wiring

Power supply 5V ─────────────── strip 5V
Power supply GND ──┬─────────── strip GND
                   └─────────── board GND
Board pin ── level shifter ──── strip DIN  (and CLK for a clocked strip)

1. Power the strip from its own 5 V supply, not from the board. A pixel at full white draws about 60 mA, so 30 pixels can want nearly 2 A. That is far more than a USB port or the board’s regulator can give.
2. Join the grounds. The supply’s GND, the strip’s GND and the board’s GND all connect together. A strip that flickers at random very often has a missing ground.
3. Use a level shifter on the data line. The board’s signal is 3.3 V and a 5 V strip expects close to 5 V. It often works without one, until the night is cold or the wire is long, and then it flickers. A 74AHCT125 (or the one-channel 74AHCT1G125) fixes it for under a dollar.

Two small extras that prevent headaches

A 330 Ω resistor in series with the data line, close to the strip, and a 1000 µF capacitor across 5 V and GND where the power enters the strip.

Setting it up in the console

Assign the pin to LED strip (WS2812) and set:

• pixels: how many LEDs are on the strip (up to 300).
• order: the color order. Try GRB first, which most WS2812 strips use. If red shows up as green, switch to RGB.
• effect: solid color or fire.

Save to node, then use the color picker in the TEST column. In a sequence, a solid strip takes any color, and Off turns it dark.

The fire effect

Set effect to fire for a flame that never repeats. It suits lanterns, jack-o’-lanterns and torches. The FIRE settings shape it:

Setting	What it changes
columns, height, zigzag	how your strip is arranged. A single strip is 1 column. A strip folded into a grid has several, and zigzag means every other row runs backwards.
brightness, speed	how bright and how lively
flame, noise	how tall and how ragged the flames are
smoke, smoke speed, smoke scale	the darker, drifting layer on top

In the TEST column a fire strip has Burn and Out. In a sequence, any value other than zero means burning.

Note

The fire effect is a port of the “Fire2023” example from the FastLED project.