10.4.4 experiment of 8 LED "running lights" in 51 single chip microcomputer control system

10.4.4 51 Single chip microcomputer control system 8 individual LED“ Running lights ” experiment
Simulation + Code

Method 1
Using the array

#include"reg52.h"

#define u8 unsigned char
#define u16 unsigned int

u16 a[] = {
    0xff, 0xfe, 0xfd, 0xfb, 0xf7, 0xef, 0xdf, 0xbf, 0x7f};

void delayms(u16 ms)
{
    
	u8 i;
	while(ms--)
		for (i=0; i<123; i++);
}

void main()
{
    
	while(1)
	{
    
		u8 i;
		for (i=1; i<=8; i++)
		{
    
			P1 = a[i];
			delayms(500);
			if (i==8) i=-1;
		}
	}
	return;
}

Method 2
Using bit operations

#include"reg52.h"

#define u8 unsigned char
#define u16 unsigned int

void delayms(u16 ms)
{
    
	u8 i;
	while(ms--)
		for (i=0; i<123; i++);
}

void main()
{
    
	P1 = 0xfe;
	while(1)
	{
    
		delayms(500);
		P1 <<= 1;
		P1 |= 0x01;
		if (P1==0x7f)
		{
    
			delayms(500);
			P1 = 0xfe;
		}
	}
}