AT89S52两单片机之间的通信 C程序

#include#define uint unsigned int#define uchar unsigned charsbit 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 charuchar 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}