MAX7219LedMatrix

Library for Arduino/ESP8266 for displaying text on one or multiple MAX7219 8x8 led matrices.

This library displays text and sets specific pixels on one or multiple 8x8 led matrices with a MAX7219 driver chip controlled through the SPI interface. These modules are relatively cheep and can be daisy chained which makes it easy to get a led text bar up and running.

For details about the MAX7219 theory, wiring, schematic, etc. there's a great post by Nick Gammon: http://www.gammon.com.au/forum/?id=11516

Currently this library supports the following operations:

set pixels
write text with a simple font
scroll text left or right
oscillate text between the two ends
Rotate characters for those displays with 90 Deg rotated LED matrices
4x faster SPI transfer compared to original code

Example

#include <SPI.h>
#include "LedMatrix.h"

#define NUMBER_OF_DEVICES 1
#define CS_PIN 2
LedMatrix ledMatrix = LedMatrix(NUMBER_OF_DEVICES, CS_PIN);

void setup() {
  Serial.begin(115200); // For debugging output
  ledMatrix.init();
  ledMatrix.setIntensity(4); // range is 0-15
  ledMatrix.setText("MAX7219 Demo");
}

void loop() {
  ledMatrix.clear();
  ledMatrix.oscillateText();
  ledMatrix.drawText();
  ledMatrix.commit(); // commit transfers the byte buffer to the displays
  delay(100);
}

Connecting the module(s)

LED Matrix	ESP8266
VCC	+3.3V
GND	GND
DIN	GPIO13 (HSPID)
CS	Choose free GPIO, e.g. GPIO2
CLK	GPIO14 (HSPICLK)

LED Matrix	Arduino Mini Pro
VCC	+5V
GND	GND
DIN	D11 (MOSI)
CS	Choose free GPIO, D2
CLK	D13 (SCK)

TheRaspyDev/MAX7219LedMatrix

MAX7219LedMatrix

Example

Connecting the module(s)