51单片机I-O扩展2

目录

• 1.实现功能
• 2.代码
• 3.原理图

1.实现功能

通过4片595级联方式实现16*16点阵屏行流水灯

2.代码

#include <reg51.h>

typedef unsigned int u16;
typedef unsigned char u8;

sbit DS = P3^4; 
sbit SH_CP = P3^6; 	  //输入时钟脉冲
sbit ST_CP = P3^5; 	  //输出

u8 ghc595_buf[8] = { 0XFE, 0XFD, 0XFB, 0XF7, 0XEF, 0XDF, 0XBF, 0X7F };


void delay_50us(u16 us) {
	while(us--);
}

void delay_ms(u16 ms)
{
	u16 i,j;
	for(i=ms;i>0;i--)
		for(j=110;j>0;j--);
}
void hc595_write_data(u8 dat1, u8 dat2, u8 dat3, dat4) {
	u8 i = 0;

	for (i = 0; i < 8; i++) {
		DS = dat4 >> 7;
		dat4 <<= 1;
		SH_CP = 0;
		delay_50us(1);
		SH_CP = 1;
		delay_50us(1);
	}

	for (i = 0; i < 8; i++) {
		DS = dat3 >> 7;
		dat3 <<= 1;
		SH_CP = 0;
		delay_50us(1);
		SH_CP = 1;
		delay_50us(1);
	}

	for (i = 0; i < 8; i++) {
		DS = dat2 >> 7;
		dat2 <<= 1;
		SH_CP = 0;
		delay_50us(1);
		SH_CP = 1;
		delay_50us(1);
	}

	for (i = 0; i < 8; i++) {
		DS = dat1 >> 7;
		dat1 <<= 1;
		SH_CP = 0;
		delay_50us(1);
		SH_CP = 1;
		delay_50us(1);
	}

	ST_CP = 0;
	delay_50us(1);
	ST_CP = 1;
	delay_ms(500);
}
void main() {
	u8 i = 0;

	while(1) {
		for (i = 0; i < 8; i++) {
			hc595_write_data(ghc595_buf[i], 0XFF, 0XFF, 0XFF);
			delay_ms(500);
		}
		for (i = 0; i < 8; i++) {
			hc595_write_data(0XFF, ghc595_buf[i], 0XFF, 0XFF);
			delay_ms(500);
		}
	}		   
}

3.原理图