Datasheet

You can also (optionally) add a white component to the color at the end, like this:

setPixelColor() does not have an immediate effect on the LEDs. To “push” the color data to the strip, call show():

This updates the whole strip at once, and despite the extra step is actually a good thing. If every call to setPixelColor()

had an immediate effect, animation would appear jumpy rather than buttery smooth.

You can query the color of a previously-set pixel using getPixelColor():

This returns a 32-bit merged color value.

The number of pixels in a previously-declared strip can be queried using numPixels():

The overall brightness of all the LEDs can be adjusted using setBrightness(). This takes a single argument, a number in

the range 0 (off) to 255 (max brightness). For example, to set a strip to 1/4 brightness:

Just like setPixel(), this does not have an immediate effect. You need to follow this with a call to show().

setBrightness() was intended to be called

once,

in setup(), to limit the current/brightness of the LEDs throughout the

life of the sketch. It is

not

intended as an animation effect itself! The operation of this function is “lossy” — it modifies

the current pixel data in RAM, not in the show() call — in order to meet NeoPixels’ strict timing requirements. Certain

animation effects are better served by leaving the brightness setting alone, modulating pixel brightness in your own

sketch logic and redrawing the full strip with setPixel().

I’m calling setPixel() but nothing’s happening!

There are two main culprits for this:

1. forgetting to call strip.begin() in setup().

2. forgetting to call strip.show() after setting pixel colors.

Another (less common) possibility is running out of RAM — see the last section below. If the program

sort of

works

but has unpredictable results, consider that.

Can I have multiple NeoPixel objects on different pins?

Certainly! Each requires its own declaration with a unique name:

uint32_t greenishwhite = strip.Color(0, 64, 0, 64);

strip.show();

uint32_t color = strip.getPixelColor(11);

uint16_t n = strip.numPixels();

strip.setBrightness(64);

Adafruit_NeoPixel strip_a = Adafruit_NeoPixel(16, 5);

Adafruit_NeoPixel strip_b = Adafruit_NeoPixel(16, 6);