Sparkfun Electronics WS2812 Breakout Hookup Manual page 14

Green Data
In/Out
Yellow GND
Each of the wire pigtails are terminated by a three-pin JST SM connector, which you can use to connect string
strips together. For the first strip in a string, you can either connect to a mating connector, or cut and strip the
wires, and connect them to your controlling device. To reuse the rest of the LED strip, check out the LED Strip
pigtail connector to easily connect the cut strips:
LED Strip Pigtail Connector (3-pin)
 CAB-14575
Addressable Through-Hole LED
If you require WS2812 LEDs in through-hole form, they are also available as a through-hole package.
Serial data in/out. Look at arrows and
labels on strip to check which it is.
Ground. 0V.
Serial data in/out. Look at arrows and
labels on strip to check which it is.
Ground. 0V.