WS2812 datasheet(67/98 Pages) RASPBERRY-PI

67 / 98 page

The library handles both

single matrices — all NeoPixels in a single uniform grid — andtiled matrices — multiple grids

combined into a larger display:

Let’s begin with the declaration for a single matrix, because it’s simpler to explain. We’ll be demonstrating the NeoPixel

Shield for Arduino in this case — an 8x5 matrix of NeoPixels. When looking at this shield with the text in a readable

orientation, the first pixel, #0, is at the top left. Each successive pixel is right one position — pixel 1 is directly to the

right of pixel 0, and so forth. At the end of each row, the next pixel is at the left side of the next row. This isn’t

something we decide in code…it’s how the NeoPixels are hard-wired in the circuit board comprising the shield.

We refer to this layout as

row major and progressive. Row major means the pixels are arranged in horizontal lines (the

opposite, in vertical lines, is

column major). Progressive means each row proceeds in the same direction. Some

matrices will reverse direction on each row, as it can be easier to wire that way. We call that a

zigzag layout.

However…for this example, we want to use the shield in the “tall” direction, so the Arduino is standing up on the desk

with the USB cable at the top. When we turn the board this way, the matrix layout changes…

https://learn.adafruit.com/adafruit-neopixel-uberguide

Page 70 of 101

WS2812 Datasheet(PDF) 67 Page - Raspberry Pi Holdings PLC