#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <termios.h>

#include <stdio.h>

#include <string.h>

#include <strings.h>



    	/* baudrate settings are defined in <asm/termbits.h>, which is

        included by <termios.h> */

        #define BAUDRATE B9600       

        /* change this definition for the correct port */

        #define MODEMDEVICE "/dev/ttyS0"

        #define _POSIX_SOURCE 1 /* POSIX compliant source */



        #define FALSE 0

        #define TRUE 1



      //#pragma ident	"%Z%%M%	%I%	%E% SMI"

      

      #if !defined(_KMDB) && !defined(_BOOT)

      

      #endif /* !_KMDB && !_BOOT */

      

      

      /*

       * Set an array of n chars starting at sp to zero.

       */

      void

      bzero(void *sp, size_t len)

      {

      	(void) memset(sp, 0, len);

      }


int write(int fd,char *Buff,int NumBytes);	

int main()
{

          int fd,res;

          struct termios oldtio,newtio;

        


        /* 

          Open modem device for reading and writing and not as controlling tty

          because we don't want to get killed if linenoise sends CTRL-C.

        */

         fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY ); 

         if (fd < 0) { perror(MODEMDEVICE); return 1; }

        

         tcgetattr(fd,&oldtio); /* save current serial port settings */

         bzero(&newtio, sizeof(newtio)); /* clear struct for new port settings */

        

        /* 

          BAUDRATE: Set bps rate. You could also use cfsetispeed and cfsetospeed.

          CRTSCTS : output hardware flow control (only used if the cable has

                    all necessary lines. See sect. 7 of Serial-HOWTO)

          CS8     : 8n1 (8bit,no parity,1 stopbit)

          CLOCAL  : local connection, no modem contol

          CREAD   : enable receiving characters

        */

         newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;

         

        /*

          IGNPAR  : ignore bytes with parity errors

          ICRNL   : map CR to NL (otherwise a CR input on the other computer

                    will not terminate input)

          otherwise make device raw (no other input processing)

        */

         newtio.c_iflag = IGNPAR | ICRNL;

         

        /*

         Raw output.

        */

         newtio.c_oflag = 0;

         

        /*

          ICANON  : enable canonical input

          disable all echo functionality, and don't send signals to calling program

        */

         newtio.c_lflag = ICANON;

         

        /* 

          initialize all control characters 

          default values can be found in /usr/include/termios.h, and are given

          in the comments, but we don't need them here

        */

         newtio.c_cc[VINTR]    = 0;     /* Ctrl-c */ 

         newtio.c_cc[VQUIT]    = 0;     /* Ctrl-\ */

         newtio.c_cc[VERASE]   = 0;     /* del */

         newtio.c_cc[VKILL]    = 0;     /* @ */

         newtio.c_cc[VEOF]     = 4;     /* Ctrl-d */

         newtio.c_cc[VTIME]    = 0;     /* inter-character timer unused */

         newtio.c_cc[VMIN]     = 1;     /* blocking read until 1 character arrives */

         newtio.c_cc[VSWTC]    = 0;     /* '\0' */

         newtio.c_cc[VSTART]   = 0;     /* Ctrl-q */ 

         newtio.c_cc[VSTOP]    = 0;     /* Ctrl-s */

         newtio.c_cc[VSUSP]    = 0;     /* Ctrl-z */

         newtio.c_cc[VEOL]     = 0;     /* '\0' */

         newtio.c_cc[VREPRINT] = 0;     /* Ctrl-r */

         newtio.c_cc[VDISCARD] = 0;     /* Ctrl-u */

         newtio.c_cc[VWERASE]  = 0;     /* Ctrl-w */

         newtio.c_cc[VLNEXT]   = 0;     /* Ctrl-v */

         newtio.c_cc[VEOL2]    = 0;     /* '\0' */

        

        /* 

          now clean the modem line and activate the settings for the port

        */

         tcflush(fd, TCIFLUSH);

         tcsetattr(fd,TCSANOW,&newtio);

        
	

        /*

          terminal settings done, now handle input

          In this example, inputting a 'z' at the beginning of a line will 

          exit the program.

        */
	
	    

        char buf[255];
	   
	buf[0]=0xff;

           
	write(fd,buf,1);
	    


         /* restore the old port settings */

         tcsetattr(fd,TCSANOW,&oldtio);
	close(fd);
	return 0;

        }

char buf[255];
	   
sprintf(buf,"255\r\n");
           
write(fd,buf,1);