51单片机：IO口扩展芯片用法(74HC165,74HC595)

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

typedef unsigned char u8;
typedef unsigned int u16;

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

#define GPIO_DIG    P0

sbit IN_SG = P1^6;
sbit IN_DATA = P1^7;
sbit IN_CLK = P3^6;

u8 read_74HC165(){
    u8 indata;
    u8 i;
    IN_SG = 0; //先置入数据
    _nop_(); //等待一个机器周期
    IN_SG = 1; //芯片切入 移位功能
    _nop_();
    
    indata = 0;
    for( i = 0; i < 8; i++ ){ //在时序电路作用下，移动8次，得到一个字节数据
        indata = indata << 1;
        IN_CLK = 0;
        _nop_();
        
        indata |= IN_DATA;
        IN_CLK = 1;    
    }
    return indata;
}

void main (){
    u8 hc165_data;
    GPIO_DIG = 0x0;
    while( 1 ) {
        hc165_data = read_74HC165();
        if( hc165_data != 0xFF ) {
            GPIO_DIG = ~hc165_data;
        }
    }   
}

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

typedef unsigned char u8;
typedef unsigned int u16;

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

#define GPIO_DIG    P0

sbit SRCLK = P3^6; //移位寄存器时钟
sbit STORE_RCLK = P3^5; //存储寄存器时钟
sbit SER = P3^4; //串口输入数据

void hc595_send_data( u8 input_data ) {
    u8 i;
    SRCLK = 1;
    STORE_RCLK = 1;
    for( i = 0 ; i < 8; i++ ){
        SER = input_data >> 7; //从最高位开始传送
        input_data <<= 1; //把次高位移到最高位

        SRCLK = 0; //时序脉冲
        _nop_();
        _nop_();
        SRCLK = 1;
    }
    STORE_RCLK = 0; //时序脉冲
    _nop_();
    _nop_();
    STORE_RCLK = 1; //把寄存器的数据 送到输出口
}

void main (){
    u8 led_num;
    led_num = 0x01; //先让D11点亮
    while( 1 ) {
        hc595_send_data( led_num );
        led_num = _crol_( led_num, 1 );
        delay( 50000 );
        delay( 50000 );
    }     
}