串口发送数据异常

只看该作者 · 2012-11-30 10:36

小弟最近一直纠结串口发送数据请大神帮忙啊!
两单片机之间用串口通信，A机用数码管显示并串口发送矩阵键盘的键值；B机接收键值并用数码管显示。0--3正常，4--7全是0,8---F正常。代码如下：
#include <reg52.h>    //52系列单片机头文件
#define uchar unsigned char
#define uint unsigned int
uchar key;
/*uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71}; */
uchar code table[]={~0x3f,~0x06,~0x5b,~0x4f,~0x66,~0x6d,~0x7d,~0x07,~0x7f,~0x6f,~0x77,~0x7c,~0x39,~0x5e,~0x79,~0x71};
void display(uchar num)
{
P0=table[num]; //显示函数只送段选数据
}
void delayms(uint xms)
{
uint i,j;
for(i=xms;i>0;i--)       //i=xms即延时约xms毫秒
  for(j=110;j>0;j--);
}
void send(uchar key_num)
{
SBUF=key_num;
while(!TI);
TI=0;
}
void matrixkeyscan()
{
uchar temp,a;
P3=0xfe;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
   delayms(10);
temp=P3;
temp=temp&0xf0;
   if(temp!=0xf0)
   {
      temp=P3;
      switch(temp)
      {
      case 0xee:
            key=0;
            break;
      case 0xde:
            key=1;
            break;
      case 0xbe:
            key=2;
            break;
      case 0x7e:
            key=3;
            break;
      }
      while(temp!=0xf0)
      {
         temp=P3;
         temp=temp&0xf0;
      }
send(key);
   }
}
P3=0xfd;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
   delayms(10);
   temp=P3;
   temp=temp&0xf0;
   if(temp!=0xf0)
   {
      temp=P3;
      switch(temp)
      {
      case 0xed:
            key=4;
            break;
      case 0xdd:
            key=5;
            break;
      case 0xbd:
            key=6;
            break;
      case 0x7d:
            key=7;
            break;
      }
      while(temp!=0xf0)
      {
         temp=P3;
         temp=temp&0xf0;
      }
send(key);
            }
}
P3=0xfb;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
   delayms(10);
   temp=P3;
   temp=temp&0xf0;
   if(temp!=0xf0)
   {
      temp=P3;
      switch(temp)
      {
      case 0xeb:
            key=8;
            break;
      case 0xdb:
            key=9;
            break;
      case 0xbb:
            key=10;
            break;
      case 0x7b:
            key=11;
            break;
      }
      while(temp!=0xf0)
      {
         temp=P3;
         temp=temp&0xf0;
      }
send(key);

   }
}
P3=0xf7;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
   delayms(10);
   temp=P3;
   temp=temp&0xf0;
   if(temp!=0xf0)
   {
      temp=P3;
      switch(temp)
      {
      case 0xe7:
            key=12;
            break;
      case 0xd7:
            key=13;
            break;
      case 0xb7:
            key=14;
            break;
      case 0x77:
            key=15;
            break;
      }
      while(temp!=0xf0)
      {
         temp=P3;
         temp=temp&0xf0;
      }
      send(key);

   }
}
}
void main()
{
      uchar i=0;
TMOD=0x20;
TH1=0xfd;
TL1=0xfd;
TR1=1;
SM0=0;
SM1=1;
EA=1;
ES=1;
while(1)
{
                        matrixkeyscan();//不停调用键盘扫描程序
                           display(key);

}
}