circuitpython-ledmatrix

The MatrixN class in this CircuitPython module maps an NxM pixel grid onto one or more 8x8 max7219 driven LED displays. It is based on the adafruit max7219 matrix library.

The LED matrices are connected in a single chain in row-first order. I.e., a 16x16 pixel grid would be displayed on 2x2 LED grids. The first two LED grids would be the rows 1 to 8, the next two LED grids would be rows 9 to 16, and so on.

Dependencies:

adafruit_bus_device
adafruit_max7219
adafruit_framebuf

Copy those modules plus ledmatrix.py to the lib directory on your board.

MatrixN has been tested on CircuitPython 5.2.0.

Use:

In your python script, use:

from ledmatrix import MatrixN
display = MatrixN(spi, cs, width, height)

SPI and the CS pin have to be set up in advance. Review the included example script for specifics.

Class:

from ledmatrix import MatrixN
display = MatrixN(spi, cs, width, height)

spi: a busio object
cs: DigitalInOut pin used for chip select
width: int pixel width of display
height: int pixel height of display
orientation: 0 or 1. "0" works with single matrix boards with connectors at the bottom. "1" rotates each data for each 8x8 matrix by 90 degrees (works with multi-matrix products commonly available with connectors on the left)

Methods:

init_display()

Initializes all of the connected LED displays. Must be called before before other commands are issued.

brightness(value)

value: brightness from 0 to 15
Sets the brightness of all connected LED displays.

write_cmd(cmd, values)

cmd: register/commad to apply to each of the values
values: a list of values that will each be paired with cmd and sent out to the displays

This is used internally by the class for controlling and showing pixels on the display and is not generally required by the developer.

text(strg, xpos, ypos, color=1)

Writes a text string into the display frame buffer. Nothing will be displayed until a show() command is issued to show the frame buffer on the LED displays

clear_all(color=0)

Clears the frame buffer to the specified color. Default is 0 which turns the LEDs off. Odd color values turn LEDs on. Even color values turn the LEDs off.

show()

Shows the current frame buffer on the LED displays.