51单片机程序驱动PCF8574点亮一个发光二极管,二极管不亮

ID:1090070 · 发表于 2023-7-30 14:20

哪位大神帮我看一下程序
#include <reg52.h>
#include <intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit scl=P0^0;
sbit sda=P0^1;

void delay(uint z)
{
  uint a,b;
  for(a=z;a>0;a--)
  for(b=200;b>0;b--);
}
void start()
{
  sda=1;
  delay(6);
  scl=1;
  delay(6);
  sda=0;
  delay(6);
}

void stop()
{
  sda=0;
  delay(6);
  scl=1;
  delay(6);
  sda=1;
  delay(6);
}

void ack()
{
  uchar i;
  scl=1;
  delay(6);
  while((sda==1)&(i<250))i++;
  delay(6);
  scl=0;
  delay(6);
}

void write_i2c_byte(uchar date)
{
  uchar temp,u;
  temp=date;
  for(u=0;u<8;u++)
  {
      temp=temp<<1;
      scl=0;
delay(6);
      sda=CY;
      delay(6);
scl=1;
      delay(6);
  }
scl=0;
delay(6);
sda=1;
delay(6);
}

void writer_PCF8574()
{
  start();
  write_i2c_byte(0x4e);
  ack();
  write_i2c_byte(0x00);
  ack();
  stop();
}

void main()
{
  sda=1;
  delay(6);
  scl=1;
  delay(6);
  writer_PCF8574();
  while(1);
}