User Manual

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

DotStar FeatherWing (https://adafru.it/AkQ) in this case — a 12x6 matrix of tiny DotStars. When looking at this

FeatherWing with the text in a readable orientation, the first pixel, #0, is at the bottom 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 up. This isn’t something we decide in code…it’s how the DotStars are hard-wired in the circuit

board comprising the FeatherWing.

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 FeatherWing in the “tall” direction, so the Feather board is standing up

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