数码管静态显示：

这个是一个共阳的数码管例子：

注意电阻排的阻值选用200欧姆

#include <reg51.h>

#define uint unsigned int
#define uchar unsigned char

uchar code seg[] = {0x40,0x79,0x24,0x30,0x19,
                                        0x12,0x02,0x78,0x00,0x10};

void delay(uint timer)
{
    uchar j = 124;
    while(timer--)
    {
        while(j--);
    }
}


void main()
{
    uchar i=0 ;
    while(1)
    {
        P2 = seg[i];
        delay(500);
        i = (i+1)%10;
    }
}

动态显示

动态显示

#include <reg51.h>

#define uint unsigned int
#define uchar unsigned char

uchar code seg[] = {0xC0,0xF9,0xA4,0xB0,0x99,
                                        0x92,0x82,0xF8,0x80,0x90};

void delay(uint timer)
{
    uchar j = 124;
    while(timer--)
    {
        while(j--);
    }
}

void main()
{
    uchar i=0 ;
    while(1)
    {
        for(i = 0;i<4;i++)
        {
            P1 = (1<<i);
            P2 = seg[i];
            delay(500);
        }
    }
}

共阴数码管的拓展

共阴和共阳数码管的程序移植，在P1.P2同时取非即可，不用更换段码表。

#include <reg51.h>

#define uint unsigned int
#define uchar unsigned char

uchar code seg[] = {0xC0,0xF9,0xA4,0xB0,0x99,
                                        0x92,0x82,0xF8,0x80,0x90};

void delay(uint timer)
{
    uchar j = 124;
    while(timer--)
    {
        while(j--);
    }
}

void main()
{
    uchar i=0 ;
    while(1)
    {
        for(i = 0;i<4;i++)
        {
            P1 = ~(1<<i);
            P2 = ~seg[i];
            delay(500);
        }
    }
}

共阴数码管段码

uchar code segD[] = {
                                        0x3f,0x06,0x5b,0x4f,0x66,
                                        0x6d,0x7d,0x07,0x7f,0x6f,
                                        0x00,0xf3};

使用74138节约IO口

注意：一定要先选同138的地址端，再送段码。
否则字码会混乱（也可以使用74ls48+74ls138）

使用74138节约IO口

#include <reg51.h>

#define uint unsigned int
#define uchar unsigned char


uchar code seg[] = {
                                        0x3f,0x06,0x5b,0x4f,0x66,
                                        0x6d,0x7d,0x07,0x7f,0x6f,
                                       0x00,0xf3};

                                                                             
void delay(uint timer)
{       
    uchar j = 124;
    while(timer--)
    {
        while(j--);
    }
}

void display(uint year, uchar month, uchar day)
{
        uint tmp;
        tmp=year/1000%10;
    
        P3=0;
        P2=seg[tmp];
        delay(1);
        
        tmp=year/100%10;
        P3=1;
        P2=seg[tmp];
        delay(1);
    
        tmp=year/10%10;
        P3=0x02;
        P2=seg[tmp];
        delay(1);
    
        tmp=year%10;
        P3=0x03;
        P2=seg[tmp];
        delay(1);

        tmp=month/10%10;
        P3=0x04;
        P2=seg[tmp];
        delay(1);
        
        tmp=month%10;
        P3=0x05;
        P2=seg[tmp];
        delay(1);
        
        tmp=day/10%10;
        P3=0x06;
        P2=seg[tmp];
        delay(1);
        
        tmp=day%10;
        P3=0x07;
        P2=seg[tmp];
        delay(1);
}


void main()
{       
        while(1)
        {
            display(2017, 12, 29);
        }
}

使用74ls48+74ls138

使用74ls48+74ls138

#include <reg51.h>

#define uint unsigned int
#define uchar unsigned char


uchar code seg[] = {
                                        0x3f,0x06,0x5b,0x4f,0x66,
                                        0x6d,0x7d,0x07,0x7f,0x6f,
                                       0x00,0xf3};

                                                                             
void delay(uint timer)
{       
    uchar j = 124;
    while(timer--)
    {
        while(j--);
    }
}

void display(uint year, uchar month, uchar day)
{
        uint tmp;
        tmp=year/1000%10;
    
        P3=0;
        P2=tmp;
        delay(1);
        
        tmp=year/100%10;
        P3=1;
        P2=tmp;
        delay(1);
    
        tmp=year/10%10;
        P3=0x02;
        P2=tmp;
        delay(1);
    
        tmp=year%10;
        P3=0x03;
        P2=tmp;
        delay(1);

        tmp=month/10%10;
        P3=0x04;
        P2=tmp;
        delay(1);
        
        tmp=month%10;
        P3=0x05;
        P2=tmp;
        delay(1);
        
        tmp=day/10%10;
        P3=0x06;
        P2=tmp;
        delay(1);
        
        tmp=day%10;
        P3=0x07;
        P2=tmp;
        delay(1);
}


void main()
{       
        while(1)
        {
            display(2017, 12, 29);
        }
}