89C52 controls MAX7219 to drive digital tube

89C52 controls MAX7219 to drive digital tubes, providing source code, schematic diagram, welding diagram, etc. Links are at the end of the article.

Schematic

Source code

max7219.h

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

* File name: MAX7219.H 

* Description: MAX7219 driver package program 

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

#ifndef _MAX7219_H_

#define _MAX7219_H_

#include

#include

//Pin definition

sbit MAX7219_CS = P2^6;

sbit MAX7219_MOSI = P2^5;

sbit MAX7219_CLK = P2^7;

//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

//Function definition

void MAX7219_WriteByte(unsigned char temp);

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 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)

{

    unsigned char i,temp;

    for(i = 0; i < 8; i++)

    {   

        MAX7219_CLK = 0;

        temp = date & 0X80;

        date = date<<1;

        if(temp == 0X80)

            MAX7219_MOSI = 1;

        else

            MAX7219_SMOKE = 0;

        MAX7219_CLK = 1; //The rising edge of the clock sends the data into the register and locks it   

    }

}

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

** 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)

{

     MAX7219_CS = 0; //Register open, waiting for data to be sent

     _nop_();

     MAX7219_WriteByte(addr); //Select register address

     _nop_();

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

     _nop_();

     MAX7219_CS = 1; //After the 16th rising edge and before the 17th rising edge, CLK must be pulled high, otherwise the data will be lost

}

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

** Function name: void MAX7219_Init(void)  

** Function description: MAX7219 initialization

** Input: None

** Global variables: None

** Calling module: None

** illustrate:

** Note:

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

void MAX7219_Init(void)      

{ 

    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

}