Arduino Uno + MAX7219 8x8 LED Matrix via SPI, using LedControl Library

We can add LedControl Library to Arduino IDE, to control 8*8 LED Matrix with MAX7219 via SPI. LedControl is a library for the MAX7219 and the MAX7221 Led display driver.
(ref: http://wayoda.github.io/LedControl/)

Open the File > Examples > LedControl > LCDemoMatrix

LCDemoMatrix.ino

//We always have to include the library
#include "LedControl.h"

/*
 Now we need a LedControl to work with.
 ***** These pin numbers will probably not work with your hardware *****
 pin 12 is connected to the DataIn 
 pin 11 is connected to the CLK 
 pin 10 is connected to LOAD 
 We have only a single MAX72XX.
 */
LedControl lc=LedControl(12,11,10,1);

/* we always wait a bit between updates of the display */
unsigned long delaytime=100;

void setup() {
  /*
   The MAX72XX is in power-saving mode on startup,
   we have to do a wakeup call
   */
  lc.shutdown(0,false);
  /* Set the brightness to a medium values */
  lc.setIntensity(0,8);
  /* and clear the display */
  lc.clearDisplay(0);
}

/*
 This method will display the characters for the
 word "Arduino" one after the other on the matrix. 
 (you need at least 5x7 leds to see the whole chars)
 */
void writeArduinoOnMatrix() {
  /* here is the data for the characters */
  byte a[5]={B01111110,B10001000,B10001000,B10001000,B01111110};
  byte r[5]={B00111110,B00010000,B00100000,B00100000,B00010000};
  byte d[5]={B00011100,B00100010,B00100010,B00010010,B11111110};
  byte u[5]={B00111100,B00000010,B00000010,B00000100,B00111110};
  byte i[5]={B00000000,B00100010,B10111110,B00000010,B00000000};
  byte n[5]={B00111110,B00010000,B00100000,B00100000,B00011110};
  byte o[5]={B00011100,B00100010,B00100010,B00100010,B00011100};

  /* now display them one by one with a small delay */
  lc.setRow(0,0,a[0]);
  lc.setRow(0,1,a[1]);
  lc.setRow(0,2,a[2]);
  lc.setRow(0,3,a[3]);
  lc.setRow(0,4,a[4]);
  delay(delaytime);
  lc.setRow(0,0,r[0]);
  lc.setRow(0,1,r[1]);
  lc.setRow(0,2,r[2]);
  lc.setRow(0,3,r[3]);
  lc.setRow(0,4,r[4]);
  delay(delaytime);
  lc.setRow(0,0,d[0]);
  lc.setRow(0,1,d[1]);
  lc.setRow(0,2,d[2]);
  lc.setRow(0,3,d[3]);
  lc.setRow(0,4,d[4]);
  delay(delaytime);
  lc.setRow(0,0,u[0]);
  lc.setRow(0,1,u[1]);
  lc.setRow(0,2,u[2]);
  lc.setRow(0,3,u[3]);
  lc.setRow(0,4,u[4]);
  delay(delaytime);
  lc.setRow(0,0,i[0]);
  lc.setRow(0,1,i[1]);
  lc.setRow(0,2,i[2]);
  lc.setRow(0,3,i[3]);
  lc.setRow(0,4,i[4]);
  delay(delaytime);
  lc.setRow(0,0,n[0]);
  lc.setRow(0,1,n[1]);
  lc.setRow(0,2,n[2]);
  lc.setRow(0,3,n[3]);
  lc.setRow(0,4,n[4]);
  delay(delaytime);
  lc.setRow(0,0,o[0]);
  lc.setRow(0,1,o[1]);
  lc.setRow(0,2,o[2]);
  lc.setRow(0,3,o[3]);
  lc.setRow(0,4,o[4]);
  delay(delaytime);
  lc.setRow(0,0,0);
  lc.setRow(0,1,0);
  lc.setRow(0,2,0);
  lc.setRow(0,3,0);
  lc.setRow(0,4,0);
  delay(delaytime);
}

/*
  This function lights up a some Leds in a row.
 The pattern will be repeated on every row.
 The pattern will blink along with the row-number.
 row number 4 (index==3) will blink 4 times etc.
 */
void rows() {
  for(int row=0;row<8;row++) {
    delay(delaytime);
    lc.setRow(0,row,B10100000);
    delay(delaytime);
    lc.setRow(0,row,(byte)0);
    for(int i=0;i<row;i++) {
      delay(delaytime);
      lc.setRow(0,row,B10100000);
      delay(delaytime);
      lc.setRow(0,row,(byte)0);
    }
  }
}

/*
  This function lights up a some Leds in a column.
 The pattern will be repeated on every column.
 The pattern will blink along with the column-number.
 column number 4 (index==3) will blink 4 times etc.
 */
void columns() {
  for(int col=0;col<8;col++) {
    delay(delaytime);
    lc.setColumn(0,col,B10100000);
    delay(delaytime);
    lc.setColumn(0,col,(byte)0);
    for(int i=0;i<col;i++) {
      delay(delaytime);
      lc.setColumn(0,col,B10100000);
      delay(delaytime);
      lc.setColumn(0,col,(byte)0);
    }
  }
}

/* 
 This function will light up every Led on the matrix.
 The led will blink along with the row-number.
 row number 4 (index==3) will blink 4 times etc.
 */
void single() {
  for(int row=0;row<8;row++) {
    for(int col=0;col<8;col++) {
      delay(delaytime);
      lc.setLed(0,row,col,true);
      delay(delaytime);
      for(int i=0;i<col;i++) {
        lc.setLed(0,row,col,false);
        delay(delaytime);
        lc.setLed(0,row,col,true);
        delay(delaytime);
      }
    }
  }
}

void loop() { 
  writeArduinoOnMatrix();
  rows();
  columns();
  single();
}

Connect MAX7219 8x8 LED Matrix to Arduino Uno as stated in the example:
- pin 12 is connected to the DataIn
- pin 11 is connected to the CLK
- pin 10 is connected to LOAD (it's cs marked on my sample)
- +5V to VCC
- GND to GND

Run.

Check the video:

Arduino Uno + SPI 8x8 LED Matrix, with MAX7219 LED driver

MAX7219 is a LED Driver from Maxim to drive either 64 individual Led's, or up to 8 digits of 7-segment displays. The drivers implement a SPI compatible slave interface that can be controlled from the Arduino using only 3 of the digital output pins. Know more about MAX7219, and MAX7221, refer to http://playground.arduino.cc/Main/MAX72XXHardware.

This example show how Arduino Uno work with DIY boeard of SPI 8x8 LED Matrix, with MAX7219 LED driver and 1088AS row cathode column anode 8x8 LED Matrix.


Visit http://playground.arduino.cc/LEDMatrix/Max7219, copy the sample sketch and un-comment your expected pattern to display.

//reference: http://playground.arduino.cc/LEDMatrix/Max7219

/* code for max 7219 from maxim, 
reduced and optimised for useing more then one 7219 in a row,
______________________________________

 Code History:
 --------------

The orginal code was written for the Wiring board by:
 * Nicholas Zambetti and Dave Mellis /Interaction Design Institute Ivrea /Dec 2004
 * http://www.potemkin.org/uploads/Wiring/MAX7219.txt

First modification by:
 * Marcus Hannerstig/  K3, malm� h�gskola /2006
 * http://www.xlab.se | http://arduino.berlios.de

This version is by:
 * tomek ness /FH-Potsdam / Feb 2007
 * http://design.fh-potsdam.de/ 

 * @acknowledgements: eric f. 

-----------------------------------

General notes: 


-if you are only using one max7219, then use the function maxSingle to control
 the little guy ---maxSingle(register (1-8), collum (0-255))

-if you are using more then one max7219, and they all should work the same, 
then use the function maxAll ---maxAll(register (1-8), collum (0-255))

-if you are using more than one max7219 and just want to change something
at one little guy, then use the function maxOne
---maxOne(Max you wane controll (1== the first one), register (1-8), 
collum (0-255))

/* During initiation, be sure to send every part to every max7219 and then
 upload it.
For example, if you have five max7219's, you have to send the scanLimit 5 times
before you load it-- other wise not every max7219 will get the data. the
function maxInUse  keeps track of this, just tell it how many max7219 you are
using.
*/

int dataIn = 2;
int load = 3;
int clock = 4;

int maxInUse = 4;    //change this variable to set how many MAX7219's you'll use

int e = 0;           // just a varialble

                     // define max7219 registers
byte max7219_reg_noop        = 0x00;
byte max7219_reg_digit0      = 0x01;
byte max7219_reg_digit1      = 0x02;
byte max7219_reg_digit2      = 0x03;
byte max7219_reg_digit3      = 0x04;
byte max7219_reg_digit4      = 0x05;
byte max7219_reg_digit5      = 0x06;
byte max7219_reg_digit6      = 0x07;
byte max7219_reg_digit7      = 0x08;
byte max7219_reg_decodeMode  = 0x09;
byte max7219_reg_intensity   = 0x0a;
byte max7219_reg_scanLimit   = 0x0b;
byte max7219_reg_shutdown    = 0x0c;
byte max7219_reg_displayTest = 0x0f;

void putByte(byte data) {
  byte i = 8;
  byte mask;
  while(i > 0) {
    mask = 0x01 << (i - 1);      // get bitmask
    digitalWrite( clock, LOW);   // tick
    if (data & mask){            // choose bit
      digitalWrite(dataIn, HIGH);// send 1
    }else{
      digitalWrite(dataIn, LOW); // send 0
    }
    digitalWrite(clock, HIGH);   // tock
    --i;                         // move to lesser bit
  }
}

void maxSingle( byte reg, byte col) {    
//maxSingle is the "easy"  function to use for a     //single max7219

  digitalWrite(load, LOW);       // begin     
  putByte(reg);                  // specify register
  putByte(col);//((data & 0x01) * 256) + data >> 1); // put data   
  digitalWrite(load, LOW);       // and load da shit
  digitalWrite(load,HIGH); 
}

void maxAll (byte reg, byte col) {    // initialize  all  MAX7219's in the system
  int c = 0;
  digitalWrite(load, LOW);  // begin     
  for ( c =1; c<= maxInUse; c++) {
  putByte(reg);  // specify register
  putByte(col);//((data & 0x01) * 256) + data >> 1); // put data
    }
  digitalWrite(load, LOW);
  digitalWrite(load,HIGH);
}

void maxOne(byte maxNr, byte reg, byte col) {    
//maxOne is for adressing different MAX7219's, 
//whilele having a couple of them cascaded

  int c = 0;
  digitalWrite(load, LOW);  // begin     

  for ( c = maxInUse; c > maxNr; c--) {
    putByte(0);    // means no operation
    putByte(0);    // means no operation
  }

  putByte(reg);  // specify register
  putByte(col);//((data & 0x01) * 256) + data >> 1); // put data 

  for ( c =maxNr-1; c >= 1; c--) {
    putByte(0);    // means no operation
    putByte(0);    // means no operation
  }

  digitalWrite(load, LOW); // and load da shit
  digitalWrite(load,HIGH); 
}


void setup () {


  pinMode(dataIn, OUTPUT);
  pinMode(clock,  OUTPUT);
  pinMode(load,   OUTPUT);

  //beginSerial(9600);
  digitalWrite(13, HIGH);  

//initiation of the max 7219
  maxAll(max7219_reg_scanLimit, 0x07);      
  maxAll(max7219_reg_decodeMode, 0x00);  // using an led matrix (not digits)
  maxAll(max7219_reg_shutdown, 0x01);    // not in shutdown mode
  maxAll(max7219_reg_displayTest, 0x00); // no display test
   for (e=1; e<=8; e++) {    // empty registers, turn all LEDs off 
    maxAll(e,0);
  }
  maxAll(max7219_reg_intensity, 0x0f & 0x0f);    // the first 0x0f is the value you can set
                                                  // range: 0x00 to 0x0f
}  

void loop () {


  //if you use just one MAX7219 it should look like this
  /*
   maxSingle(1,1);                       //  + - - - - - - -
   maxSingle(2,2);                       //  - + - - - - - -
   maxSingle(3,4);                       //  - - + - - - - -
   maxSingle(4,8);                       //  - - - + - - - -
   maxSingle(5,16);                      //  - - - - + - - -
   maxSingle(6,32);                      //  - - - - - + - -
   maxSingle(7,64);                      //  - - - - - - + -
   maxSingle(8,128);                     //  - - - - - - - +
  */

  //if you use more than one MAX7219, it should look like this
  
  maxAll(1,1);                       //  + - - - - - - -
  maxAll(2,3);                       //  + + - - - - - -
  maxAll(3,7);                       //  + + + - - - - -
  maxAll(4,15);                      //  + + + + - - - -
  maxAll(5,31);                      //  + + + + + - - -
  maxAll(6,63);                      //  + + + + + + - -
  maxAll(7,127);                     //  + + + + + + + -
  maxAll(8,255);                     //  + + + + + + + +
  
  //

  //if you use more then one max7219 the second one should look like this


  maxOne(2,1,1);                       //  + - - - - - - -
  maxOne(2,2,2);                       //  - + - - - - - -
  maxOne(2,3,4);                       //  - - + - - - - -
  maxOne(2,4,8);                       //  - - - + - - - -
  maxOne(2,5,16);                      //  - - - - + - - -
  maxOne(2,6,32);                      //  - - - - - + - -
  maxOne(2,7,64);                      //  - - - - - - + -
  maxOne(2,8,128);                     //  - - - - - - - +


  // 
  delay(2000);

}

For this example, connect the pins between the DIY board and Uno board.

• VCC - Uno 5V
• GND - Uno GND
• DIN - Uno 2
• CS - Uno 3
• CLK - Uno 4

Below video show soldering and assembling the DIY kit of SPI 8x8 LED Matrix board.


If you need to identify the pin 1 of the 1088AS 8x8 LED Matrix, refer to last post "How to identify pin 1 of 8x8 LED Matrix", part II.

More about Controlling a Led matrix or 7-segment displays with the MAX7219 or the MAX7221, in Arduino Playground.

Related:
- Arduino Uno + MAX7219 8x8 LED Matrix via SPI, using LedControl Library