serial.c

RS232通信C程序,希望对大家有用

#include<reg51.h>
//------------------------------------------------
char getData(void)
{
char c;
  while (!RI);
  c=SBUF;
  RI=0;
  return (c);
}
//-------------------------------------------------
char sendData(char c)
  {
  while (!TI);
  TI = 0;
  return (SBUF = c);
}
//-------------------------------------------------
void init(void)
{
  TMOD=0x20;//mode 2 auto reload
  TL1=0xfd;
  TH1=0xfd;//baudRate:9600

  SCON=0x52; //sm0,sm1,sm2,ren,tb,rb8,ti,ri
  PCON&=0x7f;//smod=0;
  TR1=1;//timer1 reset
}

main()
{
  char c;
  init();
  while(1)
  {
    c=getData();
    switch (c)
    {
      case '1':
	    sendData('a');
	    break;
  	  case '2':
	    sendData('b');
	    break;
	  case '3':
	    sendData('c');
		break;
	  default:
	    sendData('n');
		break;
    }
  }
}