Here is the W2812B 5050 LED Strip I bought from an auction site. W2812B(3pins) is a newer generation and W2812(4 pins) is older generation. You may select the LED voltage (5V or 12V) of your preference as long as you have a suitable power source. 

Three Wire Easy Connections:

• Arduino pin 6 to W2812B data pin
• Arduino +5V to power source 5V
• Arduino GND to power source GND
• W2812B +5V to +5V power 5V/3A adapter (Power needed depends on how many LED you hook up)
• W2812B GND to power 5V/3A adapter GND
• Arduino GND to W2812B GND

Writing the code is not an easy task! So, you need LED Library to quick light up WS1812B LED Strip.  Get FastLED library from below link and install FastLED Library for your Arduino IDE.

FastLED Library: https://github.com/FastLED/FastLED

For more advanced control, you definitely want to visit FastLED Wiki to get more information. 

Load up the sample code from FastLED library “ColorTemperature”.

You have to change the code to fit your Arduino environment settings:
1. LED_PIN = I use pin 6
2. NUM_LEDS = I have 120 in my LED Strip

Here is the source code:

#include <FastLED.h>


#include 

#define LED_PIN     6

// Information about the LED strip itself
#define NUM_LEDS    120
#define CHIPSET     WS2811
#define COLOR_ORDER GRB
CRGB leds[NUM_LEDS];

#define BRIGHTNESS  128


// FastLED v2.1 provides two color-management controls:
//   (1) color correction settings for each LED strip, and
//   (2) master control of the overall output 'color temperature' 
//
// THIS EXAMPLE demonstrates the second, "color temperature" control.
// It shows a simple rainbow animation first with one temperature profile,
// and a few seconds later, with a different temperature profile.
//
// The first pixel of the strip will show the color temperature.
//
// HELPFUL HINTS for "seeing" the effect in this demo:
// * Don't look directly at the LED pixels.  Shine the LEDs aganst
//   a white wall, table, or piece of paper, and look at the reflected light.
//
// * If you watch it for a bit, and then walk away, and then come back 
//   to it, you'll probably be able to "see" whether it's currently using
//   the 'redder' or the 'bluer' temperature profile, even not counting
//   the lowest 'indicator' pixel.
//
//
// FastLED provides these pre-conigured incandescent color profiles:
//     Candle, Tungsten40W, Tungsten100W, Halogen, CarbonArc,
//     HighNoonSun, DirectSunlight, OvercastSky, ClearBlueSky,
// FastLED provides these pre-configured gaseous-light color profiles:
//     WarmFluorescent, StandardFluorescent, CoolWhiteFluorescent,
//     FullSpectrumFluorescent, GrowLightFluorescent, BlackLightFluorescent,
//     MercuryVapor, SodiumVapor, MetalHalide, HighPressureSodium,
// FastLED also provides an "Uncorrected temperature" profile
//    UncorrectedTemperature;

#define TEMPERATURE_1 Tungsten100W
#define TEMPERATURE_2 OvercastSky

// How many seconds to show each temperature before switching
#define DISPLAYTIME 20
// How many seconds to show black between switches
#define BLACKTIME   3

void loop()
{
  // draw a generic, no-name rainbow
  static uint8_t starthue = 0;
  fill_rainbow( leds + 5, NUM_LEDS - 5, --starthue, 20);

  // Choose which 'color temperature' profile to enable.
  uint8_t secs = (millis() / 1000) % (DISPLAYTIME * 2);
  if( secs < DISPLAYTIME) {
    FastLED.setTemperature( TEMPERATURE_1 ); // first temperature
    leds[0] = TEMPERATURE_1; // show indicator pixel
  } else {
    FastLED.setTemperature( TEMPERATURE_2 ); // second temperature
    leds[0] = TEMPERATURE_2; // show indicator pixel
  }

  // Black out the LEDs for a few secnds between color changes
  // to let the eyes and brains adjust
  if( (secs % DISPLAYTIME) < BLACKTIME) {
    memset8( leds, 0, NUM_LEDS * sizeof(CRGB));
  }
  
  FastLED.show();
  FastLED.delay(8);
}

void setup() {
  delay( 3000 ); // power-up safety delay
  // It's important to set the color correction for your LED strip here,
  // so that colors can be more accurately rendered through the 'temperature' profiles
  FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalSMD5050 );
  FastLED.setBrightness( BRIGHTNESS );
}

WS2812B 5050 LED 燈條看起來如下。賣家賣的五公尺一捲，不過你可以買你要的長度。購買時要注意 W2812B只有3根腳位，如果是買到舊款的 W2812它有4根腳位，稍微注意一下。 燈條有兩種電壓 5V or 12V，我是選用 5V 的，不過你可以看看你手上的電源供應器或是電池來決定吧！

接法如下圖，只要一根資料線到 Pin 6 就好，記得要獨立提供給LED電源，因為它吃電還蠻兇的！

• Arduino pin 6 to W2812B data pin
• Arduino +5V to power source 5V
• Arduino GND to power source GND
• W2812B +5V to +5V power 5V/3A adapter (Power needed depends on how many LED you hook up)
• W2812B GND to power 5V/3A adapter GND
• Arduino GND to W2812B GND

首先，你要由此取得 FastLED Library: https://github.com/FastLED/FastLED 

如果你想要寫程式來控制燈條的話，請到 FastLED Wiki 去參考這個 Library 的用法。

接著，把 "ColorTemperature" 這支程式由 FastLED library 裡打開來。程式碼請參考上方英文的部份。只要修改兩行:

1. LED_PIN = Arduino 的資料 Pin, 我選用 6
2. NUM_LEDS = LED 串聯的總顆數，我的是 120 顆