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标题: ccs c 如何接收RS232？ [打印本页]

作者: winnie 时间: 2009-3-28 17:38
标题: ccs c 如何接收RS232？
if( kbhit() )                // 有人敲 PC 終端機的鍵盤
   {  putc ( keyin = getc() );  // echo 回終端機
      if    ( keyin == 'u' ) {...}
      else if( keyin == 't' ) {...}
      else       {...}
   }
再給你個完整的，軟硬件 RS232 範例
#include <16F877.H> // <18F452.H> // device header file from CCS-C
#use    delay(clock=20000000)
#use    rs232(baud=38400, xmit=PIN_C4, rcv=PIN_C5) // 軟件 RS232
char get_RS232_B(int16 time_slice)
{  int16 timeout=0; char cmd; time_slice*=100;
while(!kbhit()&&(++timeout<time_slice)) delay_us(10);
if(kbhit())
{
   cmd = getc(); // 從 PIN_C5 接收
   printf("\n\r RS232_B: got your command, cmd =  %C", cmd); // 送到 PIN_C4 去
   return(cmd);
} else return(0);
}
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)  // 硬件 RS232
void main()
{
char cmd, i=0;
printf("\n\n\r Press a key after each line ... ");
getc();
printf("\n\r You can get RS232 baud rate up to 115200 ... "); getc();
printf("\n\r Send keyboard command while LED flashing ... "); getc();
printf("\n\r via RS232_A (RC6, 7) or RS232_B (RC4, 5) ... "); getc();
printf("\n\r A 5 Hz high/low signal at RA5 (LED) starts now ... press a key ... ");
puts(" ");       // CCS automatically add \n\r in puts() !
while ( TRUE )
{
   if ( kbhit() )
   {  cmd = getc();
      printf("\n\r got your command from RS232_A, cmd_%u :  %C", ++i, cmd);
   }
   output_high(PIN_A5); delay_ms(100);
   output_low( PIN_A5);  // delay_ms(100);
   if ( ( cmd= get_RS232_B( 100 ) ) != 0 )  // 100 msec for RS232_B
      printf("\n\r got some command from RS232_B, cmd_%u :  %C", ++i, cmd); // 送到 PIN_C6 去
}
}

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