MAX7219 multi-chip cascade drive dot matrix microcontroller program writing experience

main.c

#include

#include "intrins.h"

#include "Max7219.h"

uchar code laji[][8]={

{0x18,0x24,0x42,0x42,0x7E,0x42,0x42,0x42},//A

{0x7C,0x42,0x42,0x7C,0x42,0x42,0x42,0x7C},//B

{0x3C,0x42,0x40,0x40,0x40,0x40,0x42,0x7C},//C

{0x7C,0x42,0x42,0x42,0x42,0x42,0x42,0x7C},//D

};

/*n milliseconds delay program*/

/*void Delay_xms(uint x)

{

  uint i,j;

  for(i=0;i  for(j=0;j<112;j++);

}*/

void main()

{

  flying i,j;

  //Delay_xms(50);

  MAX7219Init();  

  while(1)

  {

                for(j=0;j<8;j++)

    {

      for(i=0;i      {

        Max7219WR(j+1,laji[i][j]);

            }

      CS=1; _nop_(); CS=0;

                        //Delay_xms(100);

    }  

  }

}

Max7219.h

#ifndef _Max7219_H_

#define _Max7219_H_

#define uchar unsigned char

#define uint  unsigned int

#define number 4 //Number of dot matrix cascades

#define lum 5 //Brightness level, 0-F, 16 levels in total

//Define Max7219 port

sbit CLK = P2^2; //Clock Max7219_pin

sbit CS = P2^1; // latch

sbit DIN = P2^0; //data

//Write address and data to MAX7219

void Max7219WR(fly addr,fly dat)

{

  fly n=8;

        CLK=0;

        CS=0; //CS=0 is valid, CS=1 is latched

        /*Send data high bit first*/

        while(n--)

        {

          DIN = addr & 0x80;

                CLK=1;

                addr <<= 1;

                CLK=0;

        }

        n=8;

        /*Send data high bit first*/

        while(n--)

        {

          DIN = dat & 0x80;

                CLK=1;

                dat <<= 1;

                CLK=0;

        }

}

void MAX7219Init()

{

  flying i,j;

        for(i=0;i<5;i++)  //

        {

          for(j=number;j>0;j--)

                switch(i)

                {

                  case 0:Max7219WR(0x09, 0x00); break; //Decoding mode: BCD code is not decoded

                        case 1:Max7219WR(0x0A, lum); break; //Brightness 0-15, 16 levels in total

                        case 2:Max7219WR(0x0B, 0x07); break; //Scan limit; 8-bit display

                        case 3:Max7219WR(0x0C, 0x01); break; //Power-down mode: 0, normal mode: 1

                        case 4:Max7219WR(0x0F, 0x00); break; //Display test: 1; Test ends, normal display: 0

                }

                CS=1; _nop_(); CS=0; //Give a latch pulse every four writes

        }

}

#endif