000_数码管

普中51单片机的静态数码管模块电路如下图所示：

上图电路实际上是动态数码管电路，使用的是 2 个四位一体的共阴数码管组成，即 8 位数码管的段选数据 a-dp 全部并联一起引出，每位数码管的位选即公共端引出。
位选------选择哪个LED亮(LED1~LED8)； 通过74HC138控制
段选------选择LED的那个段码亮(a,b,c,d,e,f,g,dp); 通过74HC254控制
控制静态数码管循环显示0-f：

#include "reg52.h"

typedef unsigned char u8;
typedef unsigned int u16;

#define SMG_A_AP_PORT P0

u8 gsmg_code[] = {
    
    0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,
  0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

void delay(u16 us)
{
    
    
    while(us--);
}

void main()
{
    
    
    u8 i = 0;
    u8 n = sizeof(gsmg_code)/sizeof(gsmg_code[0]);
    for(i = 0;i<n;i++) {
    
     
        SMG_A_AP_PORT = gsmg_code[i];
        delay(100000);
    }
}

控制动态数码管从左到右显示数字0~7：

#include "reg52.h"

typedef unsigned char u8;
typedef unsigned int u16;

#define SMG_A_AP_PORT P0   //控制段选码

//控制38译码器的P2端口
sbit LSA = P2^2;
sbit LSB = P2^3;
sbit LSC = P2^4;
//000 ~ 111 分别对应LED0 ~ LED7  

u8 gsmg_code[] = {
    
    0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,
                  0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

void delay(u16 us)
{
    
    
    while(us--);
}

void smg_display()
{
    
    
    u8 i = 0;
    for(i = 7; i >= 0; i--)   //8个数码管
    {
    
    
        switch (i)
        {
    
    
        case 0:
            LSC = 1; LSB = 1; LSA = 1;  //LED7
            break;
        case 1:
            LSC = 1; LSB = 1; LSA = 0;  //LED6
            break;
        case 2:
            LSC = 1; LSB = 0; LSA = 1;  //LED5
            break;
        case 3:
            LSC = 1; LSB = 0; LSA = 0;  //LED4
            break;
        case 4:
            LSC = 0; LSB = 1; LSA = 1;  //LED3
            break;
        case 5:
            LSC = 0; LSB = 1; LSA = 0;  //LED2
            break;
        case 6:
            LSC = 0; LSB = 0; LSA = 1;  //LED1
            break;
        case 7:
            LSC = 0; LSB = 0; LSA = 0;  //LED0
            break;
        default:
            break;
        }
        SMG_A_AP_PORT = gsmg_code[i];
        delay(10);
        SMG_A_AP_PORT = 0x00;
    }
}

void main()
{
    
    
    while(1)
    {
    
    
        smg_display();
    }
}