C51实现流水灯

1、进行左移和右移逻辑运算

#include <reg52.h>
void delay300ms(void) //误差 0us
{
    unsigned char a, b, c;
    for (c = 123; c > 0; c--)
        for (b = 116; b > 0; b--)
            for (a = 9; a > 0; a--)
                ;
}

void main()
{
    unsigned char cnt = 0; //定义计数变量 cnt，用于移位控制
    while (1)
    {
        for (cnt = 0; cnt < 8; cnt++)
        {
            P2 = ~(0x01 << cnt);
            delay300ms();
        }
        for (cnt = 7; cnt >= 0; cnt--)
        {
            P2 = ~(0x01 << cnt);
            delay300ms();
        }
    }
}

2、将灯的状态编写成字符型数组

#include <reg52.h>
void delay500ms(void) //误差 0us
{
    unsigned char a, b, c;
    for (c = 23; c > 0; c--)
        for (b = 152; b > 0; b--)
            for (a = 70; a > 0; a--)
                ;
}
void main()
{
    unsigned int i = 0;
    unsigned char cnt = 0;
    unsigned char leds[8] = {0xFE, 0xFD, 0xFB, 0xF7, 0xEF, 0xDF, 0xBF, 0x7F};
    while (1)
    {
        for (i = 0; i < 8; i++)
        {
            delay500ms();
            P2 = leds[i];
            delay500ms();
        }
        for (i = 7; i > 0; i--)
        {
            delay500ms();
            P2 = leds[i];
            delay500ms();
        }
    }
}

3、调用（循环左移和右移）库函数

#include <reg52.h>
#include <intrins.h>

void delay500ms(void) //误差 0us
{
    unsigned char a, b, c;
    for (c = 23; c > 0; c--)
        for (b = 152; b > 0; b--)
            for (a = 70; a > 0; a--)
                ;
}

void main()
{
    unsigned int i = 0; //定义循环变量 i，用于软件延时
    unsigned char a = 0xFE;
    while (1)
    {
        for (i = 0; i < 8; i++)
        {
            delay500ms();
            P2 = a;
            a = _crol_(a, 1);
            delay500ms();
        }
        for (i = 0; i < 8; i++)
        {
            delay500ms();
            P2 = a;
            a = _cror_(a, 1);
            delay500ms();
        }
    }
}