准时钟.c

本文件包含了使用C语言编写单片机的各种入门程序

#include<reg51.h>
sbit sda=P0^2;
sbit scl=P0^3;
unsigned int b,second,minute,hour;
code int led[10]={0x11,0xd7,
0x32,0x92,0xd4,0x98,0x18,
0xd3,0x10,0x90};
void delay(int t)
{
int u;
for(;t>0;t--)
for(u=0;u<400;u++);
}
shift(int k)
{
int j,led1=led[k];
for(j=0;j<8;j++)
{
scl=0;
if(led1&0x80)sda=1;
else sda=0;
scl=1;
scl=0;
//sda=0;
led1=led1<<1;
}
}
display()
{
b=second%10;
shift(b);
b=second/10;
shift(b);
shift(0xff);
b=minute%10;
shift(b);
b=minute/10;
shift(b);
shift(0xff);
b=hour%10;
shift(b);
b=hour/10;
shift(b);
}
void main()
{
for(hour=0;hour<24;hour++)
{
for(minute=0;minute<60;minute++)
{
for(second=0;second<60;second++)
{
display();
delay(400);
}
}
}


}