Arduino MAX7219 7-Segment Display Tutorial

MAX7219 is an IC that is used to drive 7-segment LEDs (up to 8 digits), block displays (bar displays), and 64 individual LEDs that are comon cathodes. To communicate with a microcontroller, MAX7219 uses the SPI communication system. So to drive 64 LEDs only need 3 ports of the microcontroller.

In this article I will show you how to use a 7-Segement module that uses IC MAX7219 as the driver.

Required components:

• MAX7219 7-Segment Module
• Arduino Nano
• wire Jumper
• USB mini

Required Library:

• LedControl

In this tutorial I use Arduino Nano board. If you have never used it. I suggest reading my previous article about "How to Use Arduino Nano".

Connect the Arduino board to the 7-Segment module. See the picture or instruction that I wrote below:

Arduino to 7-Segment

+5V => VCC

GND => GND

D12 => DIN

D11 => CLK

D10 => CS/LOAD

After the circuit is complete. Add the "LedControl" library to the Arduino IDE.

To add a library to Arduino, you can read it in the article "How to Add an External Library to Arduino" that I made earlier".

After adding the LedControl library. You can use additional functions to control the 7-Segment module.

• Argument

addr - address of the display
digit - the position of the digit on the display (0..7)\
value - the value to be displayed. (0x00..0x0F)<p>dp    sets the decimal point.</p>

• Function

setChar(addr,digit,value.dp); //to display the char type value for 7-bit ASCII encoding

setDigit(addr,digit,value,bolean dp); //to display digits and characters in one function<br>
setRow(addr,digit,value,boolean dp); //to display the object in the desired digit

For more details, please read here.

I have sketched for the trial of this 7-Segment module. You can copy the code below, then paste it in your sketch.

//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=500;

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);
}

void hello(){

lc.setChar(0,7,'H',false);

lc.setChar(0,6,'E',false);

lc.setChar(0,5,'L',false);

lc.setChar(0,4,'L',false);

lc.setChar(0,3,'0',false);

lc.setChar(0,2,'.',false);

lc.setChar(0,1,'.',false);

lc.setChar(0,0,'.',false);

delay(delaytime+1000);

lc.clearDisplay(0);

delay(delaytime);

lc.setDigit(0,7,1,false);

delay(delaytime);

lc.setDigit(0,6,2,false);

delay(delaytime);

lc.setDigit(0,5,3,false);

delay(delaytime);

lc.setDigit(0,4,4,false);

delay(delaytime);

lc.setDigit(0,3,5,false);

delay(delaytime);

lc.setDigit(0,2,6,false);

delay(delaytime);

lc.setDigit(0,1,7,false);

delay(delaytime);

lc.setDigit(0,0,8,false);

delay(1500);

lc.clearDisplay(0);

delay(delaytime);

}

void loop() {
hello();

}

Or download the file below:

Ejoy the result.

If there are questions just write them in the comments column.

See you in next article.