MicroPython MAX7219 8x8 LED Matrix

A MicroPython library for the MAX7219 8x8 LED matrix driver. This library supports cascading multiple matrices via SPI and leverages the framebuf module for graphics rendering.

Full documentation and examples are available on the official website.

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Wiring

Pin	ESP32 Pin	Description
GND	GND	Ground
VCC	5V	Power Supply
DIN	GPIO 23	SPI MOSI (Data Input)
CS	GPIO 5	SPI SS (Chip Select)
CLK	GPIO 18	SPI SCK (Clock)

Notes:

1. Common Ground: Ensure the power supply ground (GND) is connected to the ESP32’s GND for stable operation.
2. External Power Source: Use a 5V power supply to avoid overloading the ESP32 when driving multiple matrices.

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Basic Usage

Initialize the Driver

from machine import Pin, SPI
import max7219

# Initialize SPI and MAX7219
spi = SPI(2, baudrate=10000000, polarity=1, phase=0, sck=Pin(18), mosi=Pin(23))
cs = Pin(5, Pin.OUT)

# Create a display instance
matrix = max7219.Matrix8x8(spi, cs, 1)  # One 8x8 matrix

# Display text
matrix.fill(0)          # Clear the display
matrix.text('Hi!', 0, 0, 1)  # Display "Hi!"
matrix.show()           # Render the text

# Draw a pixel
matrix.pixel(3, 3, 1)   # Turn on the pixel at (3, 3)
matrix.show()

# Draw a Line
matrix.line(0, 0, 7, 7, 1)  # Diagonal line from top-left to bottom-right
matrix.show()

# Adjust Brightness
matrix.brightness(5)    # Set brightness level (0-15)

# Scrolling Text
from time import sleep
text = "Hello, World!"
for i in range(len(text) * 8):
    matrix.fill(0)
    matrix.text(text, -i, 0, 1)  # Scroll text
    matrix.show()
    sleep(0.1)

How to Use the IconsLibrary module

Show an icon

from max7219 import Matrix8x8
from machine import Pin, SPI
from  time import sleep
import IconsLibrary

spi = SPI(1, baudrate=10000000, polarity=0, phase=0, sck=Pin(18), mosi=Pin(23))
matrix = Matrix8x8(spi, Pin(5), 1)

matrix.fill(0)  # Clear the display
matrix.brightness(0)

def display_pattern(display, pattern):
    for row_index, row_value in enumerate(pattern):
        for col_index, pixel in enumerate(row_value):
            if pixel == '1':  # If the pixel is on (1)
                display.pixel(col_index, row_index, 1)  # Turn on the pixel
    display.show()  # Update the display to reflect changes

display_pattern(matrix,IconsLibrary.HEART_HOLLOW,)

Looping through the library

from max7219 import Matrix8x8
from machine import Pin, SPI
from  time import sleep
import IconsLibrary

spi = SPI(1, baudrate=10000000, polarity=0, phase=0, sck=Pin(18), mosi=Pin(23))
matrix = Matrix8x8(spi, Pin(5), 1)

matrix.fill(0)  # Clear the display
matrix.brightness(0)

def display_pattern(display, pattern):
    for row_index, row_value in enumerate(pattern):
        for col_index, pixel in enumerate(row_value):
            if pixel == '1':  # If the pixel is on (1)
                display.pixel(col_index, row_index, 1)  # Turn on the pixel
    display.show()  # Update the display to reflect changes


ICONS = [
        IconsLibrary.HEART_SM_HOLLOW,
        IconsLibrary.HEART_MD_HOLLOW,
        IconsLibrary.HEART_HOLLOW,
        IconsLibrary.STAR,
        IconsLibrary.STAR_MD,
        IconsLibrary.STAR_SM,
        IconsLibrary.CIRCLE,
        IconsLibrary.CIRCLE_HOLLOW,
        IconsLibrary.TRIANGLE,
        IconsLibrary.TRIANGLE_HOLLOW,
        IconsLibrary.ARROW_UP,
        IconsLibrary.ARROW_UP_HOLLOW,
        IconsLibrary.ARROW_DOWN,
        IconsLibrary.ARROW_DOWN_HOLLOW,
        IconsLibrary.ARROW_LEFT,
        IconsLibrary.ARROW_LEFT_HOLLOW,
        IconsLibrary.ARROW_RIGHT,
        IconsLibrary.ARROW_RIGHT_HOLLOW,
        ]

pattern_length = len(ICONS)
while True:
    for i,pattern in enumerate(ICONS):
        display_pattern(matrix,pattern)
        matrix.fill(0)
        sleep(.2)

License

This project is licensed under the MIT License.