ATmega16 controls MAX7219 to drive digital tube

ATmega16 controls MAX7219 to drive digital tubes, and provides source code, schematics, welding diagrams, etc. See the end of the article for links. 

Schematic

Source code

MAX7219.H

/**********************************************************

* File name: MAX7219.H 

* Description: MAX7219 driver package program 

**********************************************************/

#ifndef _MAX7219_H_

#define _MAX7219_H_

#include

#include

//Function register macro definition

#define DECODEMODE 0X09 //Decoding control register address

#define INTENSITY 0X0A //Brightness control register address

#define SCANLIMIT 0X0B //Scan limit register address

#define SHUTDOWN 0X0C //Shutdown mode register address

#define DISPTEST 0X0F //Test control register address

// External callable function definition

void MAX7219_Write(unsigned char addr, unsigned char dat);

void MAX719_Init(void);

#endif

MAX7219.C

/**********************************************************

* File name: MAX7219.c 

* Description: MAX7219 driver package program 

**********************************************************/

#include "max7219.h"

/**************************************************************

** Function name: void SPI_Init(void) 

** Function description: SPI initialization

** Input: None

** Global variables: None

** Calling module: None

** illustrate:

** Note:

**************************************************************/

void SPI_Init(void) 

{

    DDRB=0xB0; //Select 7219

    SPCR=0x51; //spi settings

}

/**************************************************************

** Function name: void MAX7219_WriteByte(unsigned char date)

** Function description: Write a byte to MAX7219

** Input: unsigned char date byte content

** Global variables: None

** Calling module: None

** illustrate:

** Note:

**************************************************************/

void MAX7219_WriteByte(unsigned char date)

{

    SPDR = date; /* Start data transfer */

    while (!(SPSR & (1<

}

/**************************************************************

** Function name: void MAX7219_Write(unsigned char addr, unsigned char dat)

** Function description: Write instructions to MAX7219

** Input: unsigned char addr address 

             unsigned char dat data

** Global variables: None

** Calling module: None

** illustrate:

** Note:

**************************************************************/

void MAX7219_Write(unsigned char addr, unsigned char dat)

{

     PORTB = 0X00;

     MAX7219_WriteByte(addr); //Select register address

     MAX7219_WriteByte(dat); //Select the chip to execute the command

     PORTB = 0X10;

}

/**************************************************************

** Function name: void MAX7219_Init(void)  

** Function description: MAX7219 initialization

** Input: None

** Global variables: None

** Calling module: None

** illustrate:

** Note:

**************************************************************/

void MAX7219_Init(void)      

{ 

    SPI_Init(); //SPI function initialization

    MAX7219_Write(SHUTDOWN, 0x01); //Shutdown mode register; shutdown state, the lowest bit D0 = 0; normal state, the lowest bit D0 = 1

    MAX7219_Write(DISPTEST, 0x00); //Display test register; in test state, the lowest bit D0 = 1, all bits are displayed brightly; in normal working state, the lowest bit D0 = 1

    MAX7219_Write(DECODEMODE, 0xff); //decoding control register; 0XFF, full decoding

    MAX7219_Write(SCANLIMIT, 0x07); //Scan limit register; set the number of LEDs to be displayed (1~8). If it is set to 0xX4, LEDs 0~5 will be displayed.

    MAX7219_Write(INTENSITY, 0x08); //Brightness control register; there are 16 levels to choose from, used to set the display brightness of the LED, 0X00-0X0F

}