PewPew – LED matrix and button driver

This is an internal module to be used by the pew.py library from https://github.com/pewpew-game/pew-pewpew-standalone-10.x to handle the LED matrix display and buttons on the pewpew10 board.

Usage:

This singleton class is instantiated by the ``pew`` library, and
used internally by it. All user-visible interactions are done through
that library.
class _pew.PewPew(buffer, rows, cols, buttons)

Initializes matrix scanning routines.

The buffer is a 64 byte long bytearray that stores what should be displayed on the matrix. rows and cols are both lists of eight DigitalInputOutput objects that are connected to the matrix rows and columns. buttons is a DigitalInputOutput object that is connected to the common side of all buttons (the other sides of the buttons are connected to rows of the matrix).