Introduction

CircuitPython driver for the MAX7219 LED matrix driver chip.

See here for the equivalent MicroPython driver.

Dependencies

This driver depends on:

• Adafruit CircuitPython

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.

Usage Example

adafruit_max7219.Matrix8x8 Example

from adafruit_max7219 import matrices
from board import TX, RX, A2
import busio
import digitalio
import time

clk = RX
din = TX
cs = digitalio.DigitalInOut(A2)

spi = busio.SPI(clk, MOSI=din)
display = matrices.Matrix8x8(spi, cs)
while True:
    display.brightness(3)

    display.fill(1)
    display.pixel(3, 3)
    display.pixel(3, 4)
    display.pixel(4, 3)
    display.pixel(4, 4)
    display.show()
    time.sleep(3.0)

    display.clear_all()
    s = 'Hello, World!'
    for c in range(len(s)*8):
        display.fill(0)
        display.text(s,-c,0)
        display.show()
        time.sleep(0.25)

adafruit_max7219.BCDDigits Example

from adafruit_max7219 import bcddigits
from board import TX, RX, A2
import bitbangio
import digitalio

clk = RX
din = TX
cs = digitalio.DigitalInOut(A2)

spi = bitbangio.SPI(clk, MOSI=din)
display = bcddigits.BCDDigits(spi, cs, nDigits=8)
display.clear_all()
display.show_str(0,'{:9.2f}'.format(-1234.56))
display.show()

Contributing

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.

Building locally

To build this library locally you'll need to install the circuitpython-build-tools package.

python3 -m venv .env
source .env/bin/activate
pip install circuitpython-build-tools

Once installed, make sure you are in the virtual environment:

source .env/bin/activate

Then run the build:

circuitpython-build-bundles --filename_prefix adafruit-circuitpython-max7219 --library_location .

Sphinx documentation

Sphinx is used to build the documentation based on rST files and comments in the code. First, install dependencies (feel free to reuse the virtual environment from above):

python3 -m venv .env
source .env/bin/activate
pip install Sphinx sphinx-rtd-theme

Now, once you have the virtual environment activated:

cd docs
sphinx-build -E -W -b html . _build/html

This will output the documentation to docs/_build/html. Open the index.html in your browser to view them. It will also (due to -W) error out on any warning like Travis will. This is a good way to locally verify it will pass.