Grove - RGB Led matrix w/Driver pixel size

In a first time :
I want to define an matrix that 8x16 with two 8x8. I already change the matrix address but I don’t find how to define matrix.
In a second time :
I want to change letter and number size in 5x4.
Thanks for your help.

This is our product Wiki. I hope it can help you.

Hi, thanks for answer. I already consult the product Wiki but its don’t respond my questioning.