jianpancxu.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,keycode;
code char  led[17]={0x11,0xd7,
0x32,0x92,0xd4,0x98,0x18,0xd3,
0x10,0x90,0x50,0x1c,0x39,0x16,
0x38,0x78,0xff};

void delay(int k)
{
int l;
for(;k>0;k--)
for(l=0;l<400;l++);
}

shift(int k)
{
int t,led1=led[k];
for(t=0;t<8;t++)
{
scl=0;
if(led1&0x80)
sda=1;
else 
sda=0;
scl=1;
scl=0;
sda=0;
led1=led1<<1;
}
}

display()
{
shift(16);
shift(16);
shift(16);
shift(16);
shift(16);
shift(16);
shift(16);
shift(b);
}

keyscan()
{
int k1,k2;
P2=0xf0;
k1=P2; 
P2=0x0f;
k2=P2;
keycode=k1+k2;
switch(keycode)
{
case 0xe7: b=0;break;
case 0xd7: b=1;break;
case 0xb7: b=2;break;
case 0x77: b=3;break;

case 0xeb: b=4;break;
case 0xdb: b=5;break;
case 0xbb: b=6;break;
case 0x7b: b=7;break;

case 0xed: b=8;break;
case 0xdd: b=9;break;
case 0xbd: b=10;break;
case 0x7d: b=11;break;

case 0xee: b=12;break;
case 0xde: b=13;break;
case 0xbe: b=14;break;
case 0x7e: b=15;break;
} 

}

 main()
{
while(1)
{
keyscan();
display();
delay(200);
}
}