The shields are nice, but not everybody has a D1 Mini, and not everybody wants to put that matrix on top of their dev board. Sure, you can just use wires for the shield, but with such a small and convenient chip, it makes sense to make an even smaller breakout board -- one that you could tile easily. So I made one that is exactly the size of the matrix:
I soldered the pin header sideways here, but you can also solder it normally, and then you can tile the boards easily. I also broke out the address pin this time, so you can change the I2C address of the board by connecting it to one of the other pins (you get 4 different addresses this way).
There is also the audio pin, which you can use to control the brightness or to feed the built-in equalizer. I will be experimenting some more with that once the microphones arrive.