Setup
There are a few lines of code required to set up your sketch to use the library. First, call the constructor near the
top of your code (before setup() , you'll probably want it to be a global variable).
#define PIN 4
#define LED_COUNT 8
// Create an instance of the Adafruit_NeoPixel class called "leds".
// That'll be what we refer to from here on...
Adafruit_NeoPixel leds = Adafruit_NeoPixel(LED_COUNT, PIN, NEO_GRB + NEO_KHZ800);
The PIN and LED_COUNT parameters in that function call should be set, respectively, to the Arduino pin you've
connected to the first breakout's "DIN" pin and the total number of breakout boards you have linked up.
The rest of the setup is calling the leds.begin() function somewhere near the beginning of the setup() function.
Setting An LED
Setting an LED with the Adafruit NeoPixel library is a two step process. First, you have to set a pixel color using
the leds.setPixelColor(position, color) command. The color parameter in that function can either be a 24-bit
RGB color-code, or three separate bytes for each color. For example:
leds.setPixelColor(3, 0xFF00FF); // Set fourth LED to full red, no green, full blue
leds.setPixelColor(3, 0xFF, 0x00, 0xFF) // Also set fourth LED to full red, no green, full blue
Setting a pixel's color does not equate to that pixel actually turning on though. For that, you need to call
leds.show() . Note that when this function is called any LED that was previously set will turn on.
The Rest of the Code
After you've gotten the hang of using the NeoPixel library, the remaining parts of the sketch are finding ways to
maniuplate the pixel colors. There are some fun functions in this example code, which create the classic "cylon"
larson scanner, or draw a rainbow. We hope you can adapt them to make even more creative animations.
The included "WS2812_Definitions.h" file defines a huge list of standard colors. In there you'll find anything from
navy to saddle brown to ghost white.
Have fun!
FastLED Alternative Library
Looking for an alternative library? Try checking out the FastLED library for more advanced features. The library
also supports other LED chipsets.
FASTLED GITHUB REPO
Resources and Going Further
For more information about the WS2812 and WS2812B, check out the resources below:
Breakout Board Schematic (PDF)
Breakout Board Eagle Files (ZIP)
Breakout Board GitHub Repo
Datasheet
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