@tutorial:
MAX7219 LED MATRIX with Arduino
This is a very short example. How to conenct these dot matrixes one to the other. We shift data from the arduino and from one MAX7219 driver to the next. By that we could scroll text and other icons. You have all that you need below.
by: ELECTRONOOBS on 2026-11-04
TUTORIAL_INDEX
First, you need a dot matrx module like this one on this link. This uses serial data to show text or any other icon. To send data, all we have to do is to send data on the data pin.
Ok, make the serial connection between the Arduino and first dot matrix as below. Then, from each matrix to the next. This setup could control up to 8 matrices.
First, we need the LedControl.h library that you could dowload from below. So, for that, go below and downlaod that library. It will be a .zip file. Open Arduino IDE and go to sketch, include library, add .zip library and select the downlaoded file. Now the library is installed. You could downlaod the example code or just copy/paste it from below.
/* Dot matrix control Scrolling
* Tutorial: https://www.electronoobs.com/eng_arduino_tut56.php
Schematic: https://www.electronoobs.com/eng_arduino_tut56_sch1.php
LedControl library: https://www.electronoobs.com/eng_arduino_ledcontrol.php
*/
#include <LedControl.h> //LedControl library: https://www.electronoobs.com/ledcontrol.php
const int numDevices = 2; // number of MAX7219s used in this case 2
const long scrollDelay = 40; // adjust scrolling speed
unsigned long bufferLong [14] = {0};
LedControl lc=LedControl(12,11,10,numDevices);//DATA | CLK | CS/LOAD | number of matrices
const unsigned char scrollText[] PROGMEM ={" ELECTRONOOBS ! ! ! 1 2 3 "};
void setup()
{
for (int x=0; x<numDevices; x++)
{
lc.shutdown(x,false); //The MAX72XX is in power-saving mode on startup
lc.setIntensity(x,8); // Set the brightness to default value
lc.clearDisplay(x); // and clear the display
}
}
void loop(){
scrollMessage(scrollText); //scrollFont();
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
const unsigned char font5x7 [] PROGMEM = { //Numeric Font Matrix (Arranged as 7x font data + 1x kerning data)
B00000000, //Space (Char 0x20)
B00000000,
B00000000,
B00000000,
B00000000,
B00000000,
B00000000,
3,//cambias el tamaño del espacio entre letras
B01000000, //!
B01000000,
B01000000,
B01000000,
B01000000,
B00000000,
B01000000,
2,
B10100000, //"
B10100000,
B10100000,
B00000000,
B00000000,
B00000000,
B00000000,
4,
B01010000, //#
B01010000,
B11111000,
B01010000,
B11111000,
B01010000,
B01010000,
6,
B00100000, //$
B01111000,
B10100000,
B01110000,
B00101000,
B11110000,
B00100000,
6,
B11000000, //%
B11001000,
B00010000,
B00100000,
B01000000,
B10011000,
B00011000,
6,
B01100000, //&
B10010000,
B10100000,
B01000000,
B10101000,
B10010000,
B01101000,
6,
B11000000, //'
B01000000,
B10000000,
B00000000,
B00000000,
B00000000,
B00000000,
3,
B00100000, //(
B01000000,
B10000000,
B10000000,
B10000000,
B01000000,
B00100000,
4,
B10000000, //)
B01000000,
B00100000,
B00100000,
B00100000,
B01000000,
B10000000,
4,
B00000000, //*
B00100000,
B10101000,
B01110000,
B10101000,
B00100000,
B00000000,
6,
B00000000, //+
B00100000,
B00100000,
B11111000,
B00100000,
B00100000,
B00000000,
6,
B00000000, //,
B00000000,
B00000000,
B00000000,
B11000000,
B01000000,
B10000000,
3,
B00000000, //-
B00000000,
B11111000,
B00000000,
B00000000,
B00000000,
B00000000,
6,
B00000000, //.
B00000000,
B00000000,
B00000000,
B00000000,
B11000000,
B11000000,
3,
B00000000, ///
B00001000,
B00010000,
B00100000,
B01000000,
B10000000,
B00000000,
6,
B01110000, //0
B10001000,
B10011000,
B10101000,
B11001000,
B10001000,
B01110000,
6,
B01000000, //1
B11000000,
B01000000,
B01000000,
B01000000,
B01000000,
B11100000,
4,
B01110000, //2
B10001000,
B00001000,
B00010000,
B00100000,
B01000000,
B11111000,
6,
B11111000, //3
B00010000,
B00100000,
B00010000,
B00001000,
B10001000,
B01110000,
6,
B00010000, //4
B00110000,
B01010000,
B10010000,
B11111000,
B00010000,
B00010000,
6,
B11111000, //5
B10000000,
B11110000,
B00001000,
B00001000,
B10001000,
B01110000,
6,
B00110000, //6
B01000000,
B10000000,
B11110000,
B10001000,
B10001000,
B01110000,
6,
B11111000, //7
B10001000,
B00001000,
B00010000,
B00100000,
B00100000,
B00100000,
6,
B01110000, //8
B10001000,
B10001000,
B01110000,
B10001000,
B10001000,
B01110000,
6,
B01110000, //9
B10001000,
B10001000,
B01111000,
B00001000,
B00010000,
B01100000,
6,
B00000000, //:
B11000000,
B11000000,
B00000000,
B11000000,
B11000000,
B00000000,
3,
B00000000, //;
B11000000,
B11000000,
B00000000,
B11000000,
B01000000,
B10000000,
3,
B00010000, //<
B00100000,
B01000000,
B10000000,
B01000000,
B00100000,
B00010000,
5,
B00000000, //=
B00000000,
B11111000,
B00000000,
B11111000,
B00000000,
B00000000,
6,
B10000000, //>
B01000000,
B00100000,
B00010000,
B00100000,
B01000000,
B10000000,
5,
B01110000, //?
B10001000,
B00001000,
B00010000,
B00100000,
B00000000,
B00100000,
6,
B01110000, //@
B10001000,
B00001000,
B01101000,
B10101000,
B10101000,
B01110000,
6,
B01110000, //A
B10001000,
B10001000,
B10001000,
B11111000,
B10001000,
B10001000,
6,
B11110000, //B
B10001000,
B10001000,
B11110000,
B10001000,
B10001000,
B11110000,
6,
B01110000, //C
B10001000,
B10000000,
B10000000,
B10000000,
B10001000,
B01110000,
6,
B11100000, //D
B10010000,
B10001000,
B10001000,
B10001000,
B10010000,
B11100000,
6,
B11111000, //E
B10000000,
B10000000,
B11110000,
B10000000,
B10000000,
B11111000,
6,
B11111000, //F
B10000000,
B10000000,
B11110000,
B10000000,
B10000000,
B10000000,
6,
B01110000, //G
B10001000,
B10000000,
B10111000,
B10001000,
B10001000,
B01111000,
6,
B10001000, //H
B10001000,
B10001000,
B11111000,
B10001000,
B10001000,
B10001000,
6,
B11100000, //I
B01000000,
B01000000,
B01000000,
B01000000,
B01000000,
B11100000,
4,
B00111000, //J
B00010000,
B00010000,
B00010000,
B00010000,
B10010000,
B01100000,
6,
B10001000, //K
B10010000,
B10100000,
B11000000,
B10100000,
B10010000,
B10001000,
6,
B10000000, //L
B10000000,
B10000000,
B10000000,
B10000000,
B10000000,
B11111000,
6,
B10001000, //M
B11011000,
B10101000,
B10101000,
B10001000,
B10001000,
B10001000,
6,
B10001000, //N
B10001000,
B11001000,
B10101000,
B10011000,
B10001000,
B10001000,
6,
B01110000, //O
B10001000,
B10001000,
B10001000,
B10001000,
B10001000,
B01110000,
6,
B11110000, //P
B10001000,
B10001000,
B11110000,
B10000000,
B10000000,
B10000000,
6,
B01110000, //Q
B10001000,
B10001000,
B10001000,
B10101000,
B10010000,
B01101000,
6,
B11110000, //R
B10001000,
B10001000,
B11110000,
B10100000,
B10010000,
B10001000,
6,
B01111000, //S
B10000000,
B10000000,
B01110000,
B00001000,
B00001000,
B11110000,
6,
B11111000, //T
B00100000,
B00100000,
B00100000,
B00100000,
B00100000,
B00100000,
6,
B10001000, //U
B10001000,
B10001000,
B10001000,
B10001000,
B10001000,
B01110000,
6,
B10001000, //V
B10001000,
B10001000,
B10001000,
B10001000,
B01010000,
B00100000,
6,
B10001000, //W
B10001000,
B10001000,
B10101000,
B10101000,
B10101000,
B01010000,
6,
B10001000, //X
B10001000,
B01010000,
B00100000,
B01010000,
B10001000,
B10001000,
6,
B10001000, //Y
B10001000,
B10001000,
B01010000,
B00100000,
B00100000,
B00100000,
6,
B11111000, //Z
B00001000,
B00010000,
B00100000,
B01000000,
B10000000,
B11111000,
6,
B11100000, //[
B10000000,
B10000000,
B10000000,
B10000000,
B10000000,
B11100000,
4,
B00000000, //(Backward Slash)
B10000000,
B01000000,
B00100000,
B00010000,
B00001000,
B00000000,
6,
B11100000, //]
B00100000,
B00100000,
B00100000,
B00100000,
B00100000,
B11100000,
4,
B00100000, //^
B01010000,
B10001000,
B00000000,
B00000000,
B00000000,
B00000000,
6,
B00000000, //_
B00000000,
B00000000,
B00000000,
B00000000,
B00000000,
B11111000,
6,
B10000000, //`
B01000000,
B00100000,
B00000000,
B00000000,
B00000000,
B00000000,
4,
B00000000, //a
B00000000,
B01110000,
B00001000,
B01111000,
B10001000,
B01111000,
6,
B10000000, //b
B10000000,
B10110000,
B11001000,
B10001000,
B10001000,
B11110000,
6,
B00000000, //c
B00000000,
B01110000,
B10001000,
B10000000,
B10001000,
B01110000,
6,
B00001000, //d
B00001000,
B01101000,
B10011000,
B10001000,
B10001000,
B01111000,
6,
B00000000, //e
B00000000,
B01110000,
B10001000,
B11111000,
B10000000,
B01110000,
6,
B00110000, //f
B01001000,
B01000000,
B11100000,
B01000000,
B01000000,
B01000000,
6,
B00000000, //g
B01111000,
B10001000,
B10001000,
B01111000,
B00001000,
B01110000,
6,
B10000000, //h
B10000000,
B10110000,
B11001000,
B10001000,
B10001000,
B10001000,
6,
B01000000, //i
B00000000,
B11000000,
B01000000,
B01000000,
B01000000,
B11100000,
4,
B00010000, //j
B00000000,
B00110000,
B00010000,
B00010000,
B10010000,
B01100000,
5,
B10000000, //k
B10000000,
B10010000,
B10100000,
B11000000,
B10100000,
B10010000,
5,
B11000000, //l
B01000000,
B01000000,
B01000000,
B01000000,
B01000000,
B11100000,
4,
B00000000, //m
B00000000,
B11010000,
B10101000,
B10101000,
B10001000,
B10001000,
6,
B00000000, //n
B00000000,
B10110000,
B11001000,
B10001000,
B10001000,
B10001000,
6,
B00000000, //o
B00000000,
B01110000,
B10001000,
B10001000,
B10001000,
B01110000,
6,
B00000000, //p
B00000000,
B11110000,
B10001000,
B11110000,
B10000000,
B10000000,
6,
B00000000, //q
B00000000,
B01101000,
B10011000,
B01111000,
B00001000,
B00001000,
6,
B00000000, //r
B00000000,
B10110000,
B11001000,
B10000000,
B10000000,
B10000000,
6,
B00000000, //s
B00000000,
B01110000,
B10000000,
B01110000,
B00001000,
B11110000,
6,
B01000000, //t
B01000000,
B11100000,
B01000000,
B01000000,
B01001000,
B00110000,
6,
B00000000, //u
B00000000,
B10001000,
B10001000,
B10001000,
B10011000,
B01101000,
6,
B00000000, //v
B00000000,
B10001000,
B10001000,
B10001000,
B01010000,
B00100000,
6,
B00000000, //w
B00000000,
B10001000,
B10101000,
B10101000,
B10101000,
B01010000,
6,
B00000000, //x
B00000000,
B10001000,
B01010000,
B00100000,
B01010000,
B10001000,
6,
B00000000, //y
B00000000,
B10001000,
B10001000,
B01111000,
B00001000,
B01110000,
6,
B00000000, //z
B00000000,
B11111000,
B00010000,
B00100000,
B01000000,
B11111000,
6,
B00100000, //{
B01000000,
B01000000,
B10000000,
B01000000,
B01000000,
B00100000,
4,
B10000000, //|
B10000000,
B10000000,
B10000000,
B10000000,
B10000000,
B10000000,
2,
B10000000, //}
B01000000,
B01000000,
B00100000,
B01000000,
B01000000,
B10000000,
4,
B00000000, //~
B00000000,
B00000000,
B01101000,
B10010000,
B00000000,
B00000000,
6,
B01100000, // (Char 0x7F)
B10010000,
B10010000,
B01100000,
B00000000,
B00000000,
B00000000,
5,
B00000000, // smiley
B01100000,
B01100110,
B00000000,
B10000001,
B01100110,
B00011000,
5
};
void scrollFont() {
for (int counter=0x20;counter<0x80;counter++){
loadBufferLong(counter);
delay(500);
}
}
// Scroll Message
void scrollMessage(const unsigned char * messageString) {
int counter = 0;
int myChar=0;
do {
// read back a char
myChar = pgm_read_byte_near(messageString + counter);
if (myChar != 0){
loadBufferLong(myChar);
}
counter++;
}
while (myChar != 0);
}
// Load character into scroll buffer
void loadBufferLong(int ascii){
if (ascii >= 0x20 && ascii <=0x7f){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long c = pgm_read_byte_near(font5x7 + ((ascii - 0x20) * 8) + a); // Index into character table to get row data
unsigned long x = bufferLong [a*2]; // Load current scroll buffer
x = x | c; // OR the new character onto end of current
bufferLong [a*2] = x; // Store in buffer
}
byte count = pgm_read_byte_near(font5x7 +((ascii - 0x20) * 8) + 7); // Index into character table for kerning data
for (byte x=0; x<count;x++){
rotateBufferLong();
printBufferLong();
delay(scrollDelay);
}
}
}
// Rotate the buffer
void rotateBufferLong(){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long x = bufferLong [a*2]; // Get low buffer entry
byte b = bitRead(x,31); // Copy high order bit that gets lost in rotation
x = x<<1; // Rotate left one bit
bufferLong [a*2] = x; // Store new low buffer
x = bufferLong [a*2+1]; // Get high buffer entry
x = x<<1; // Rotate left one bit
bitWrite(x,0,b); // Store saved bit
bufferLong [a*2+1] = x; // Store new high buffer
}
}
// Display Buffer on LED matrix
void printBufferLong(){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long x = bufferLong [a*2+1]; // Get high buffer entry
byte y = x; // Mask off first character
lc.setRow(3,a,y); // Send row to relevent MAX7219 chip
x = bufferLong [a*2]; // Get low buffer entry
y = (x>>24); // Mask off second character
lc.setRow(2,a,y); // Send row to relevent MAX7219 chip
y = (x>>16); // Mask off third character
lc.setRow(1,a,y); // Send row to relevent MAX7219 chip
y = (x>>8); // Mask off forth character
lc.setRow(0,a,y); // Send row to relevent MAX7219 chip
}
}Comments
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