单片机memoirs 12 MAX485 On May 6,2013

#include //发送程序
unsigned char l,h,key;
sbit cs=P3^7; 
void delay(unsigned t)
{ while(t--);}  
void main()
{


    TMOD=0x20;     
TH1=0xe8;      
TL1=0xe8;
TR1=1;        
SM1=1; 
REN=1;
ES=1;
EA=1;  
cs=1;
while(1)
{
   P2=0xf0;
l=P2;
   l=l&0xf0;
if(l!=0xf0)
{
   delay(200);
if(l!=0xf0)
{
   l=P2&0xf0;
l=l|0x0f;
P2=l;
h=P2;  
h=h&0x0f;
   l=l&0xf0;
key=h+l;

}
}
   switch(key)
{
case 0xee:SBUF=0xc0;while(TI==0);TI=0;break;
case 0xde:SBUF=0xf9;while(TI==0);TI=0;break;
case 0xbe:SBUF=0xa4;while(TI==0);TI=0;break;
case 0x7e:SBUF=0xb0;while(TI==0);TI=0;break;
case 0xed:SBUF=0x99;while(TI==0);TI=0;break;
case 0xdd:SBUF=0x92;while(TI==0);TI=0;break;
case 0xbd:SBUF=0x82;while(TI==0);TI=0;break;
case 0x7d:SBUF=0xf8;while(TI==0);TI=0;break;
case 0xeb:SBUF=0x80;while(TI==0);TI=0;break;
case 0xdb:SBUF=0x90;while(TI==0);TI=0;break;
case 0xbb:SBUF=0x88;while(TI==0);TI=0;break;
case 0x7b:SBUF=0x83;while(TI==0);TI=0;break;
case 0xe7:SBUF=0xc6;while(TI==0);TI=0;break;
case 0xd7:SBUF=0xa1;while(TI==0);TI=0;break;
case 0xb7:SBUF=0x86;while(TI==0);TI=0;break;
case 0x77:SBUF=0x8e;while(TI==0);TI=0;break;
   }
}
}

#include //接收
sbit cs=P3^7;
void main()
{
  TMOD=0x20;
TH1=0xe8;
TL1=0xe8;
TR1=1;
SM1=1;
REN=1;
ES=1;   
EA=1;
cs=0;
while(1);
}   
void receive() interrupt 4
{
  P1=SBUF;
while(RI==0);
RI=0;
}
c：
MAX485.zip