#include
#define uint unsigned int
#define uchar unsigned char
sbit key1 = P1^0;   //按键位定义
sbit key2 = P1^1;
sbit key3 = P1^2;
sbit key4 = P1^3;

void send(uchar key_num) //通过串口发送按键值子函数
{
 SBUF = key_num;
 while(!TI);
 TI = 0;
}

void delay(uint z)  //延时_ms子函数
{
 uint x,y;
 for(x = 0;x   for(y = 0;y<125;y++);  
}

uint key_scan()   //键盘扫描子函数，带返回值num
{ 
 uint num;
 if(key1 == 0)  //键1按下则数码管将显示1
 { 
  delay(5);
   if(key1 ==0)
   {num = 1;}
 }


 if(key2 == 0)  //键2按下则数码管将显示2
 { 
  delay(5);
   if(key2 ==0)
   {num = 2;}
 }


 if(key3 == 0)  //键3按下则数码管将显示3
 { 
  delay(5);
   if(key3 ==0)
   {num = 3;}
 }


 if(key4 == 0)  //键4按下则数码管将显示4
 { 
  delay(5);
   if(key4 ==0)
   {num = 4;}
 }

 return num;  //返回值为num
}

void scon_init()  //初始化串口子函数
{
 TMOD = 0x20;
 TH1 = 0xfd;
 TL1 = 0xfd;
 TR1 = 1;
 SM0 = 0;
 SM1 = 1;
 EA = 1;
 ES = 1;
}
void main()
{
 scon_init();  //初始化串口
 while(1)
 {
  send(key_scan()); //不停扫描并发送按键值
 }
}

 

 


#include
#define uint unsigned int
#define uchar unsigned char

uchar code tab[]={   //数码管字形
0x40,0x79,0x24,0x30,
0x19,0x12,0x02,0x78,
0x00,0x10,0x08,0x03,
0x46,0x21,0x06,0x0e};

void scon_init()  //串口寄存器初始化
{
 TMOD = 0x20;
 TH1 = 0xfd;
 TL1 = 0xfd;
 TR1 = 1;
 REN = 1;  //注意REN的位置
 SM0 = 0;
 SM1 = 1;
 EA = 1;
 ES = 1;
}

void main()
{
 scon_init();  //调用串口初始化子函数
 while(1);   //等待串口中断
}

void ser() interrupt 4  //串口中断子函数
{
 uchar a;
 RI = 0;
 a = SBUF;    //将接收到在SBUF中的key值送给变量a
 P2 = tab[a];   //在串口中断中显示字形
}