tty.c

本程序中有main.c、rfid.h、rfid.c、tty.h、tty.c和makefile六个文件

/************************************************
 *  TTY SERIAL ROUTES 
 *  use ttyS1 to ctrol GPRS
 *  by Zou jian guo <[e-mail]>   
 *  2004-11-02
 *  
 *  edited by wbin <[e-mail]>
 *  2005-01-19
 *  
*************************************************/
//#include <termios.h>
//#include <stdio.h>
//#include <unistd.h>
//#include <fcntl.h>
//#include <sys/signal.h>
//#include <pthread.h>
//#include "tty.h"

#include <sys/types.h>                                                  
#include <sys/stat.h>                                                      
#include <fcntl.h>                                                       
#include <termios.h>                                                    
#include <stdio.h>    

#define BAUDRATE B115200
#define COM1 "/dev/ttyS0"
#define COM2 "/dev/ttyS2"

static int fd;
static struct termios oldtio,newtio;

//==============================================================
int tty_end()
{
  //	tcsetattr(fd,TCSANOW,&oldtio);	 	/* restore old modem setings */
//  	tcsetattr(0,TCSANOW,&oldstdtio); 	/* restore old tty setings */
	printf("fd=%d\n",fd);
  	close(fd);
	printf("fd=%d has been close\n",fd);
}

//==============================================================
int tty_read(char *buf,int nbytes)
{
	return read(fd,buf,nbytes);
}
//==============================================================
int tty_write(char *buf,int nbytes)
{
	int i;
	for(i=0; i<nbytes; i++) {
		write(fd,&buf[i],1);
		usleep(100);
	}
	return tcdrain(fd);
}

//==============================================================
int tty_writecmd(char *buf,int nbytes)
{
	int i;
	for(i=0; i<nbytes; i++) {
		write(fd,&buf[i],1);
		usleep(100);
	}
	write(fd,"\r",1);
	usleep(300000);
	return tcdrain(fd);
}

//==============================================================
int tty_init()
{
	printf("start to open com1\n");
	fd = open(COM1, O_RDWR ); //| O_NONBLOCK);//
	printf("fd=%d\n",fd);
	if (fd <0) {
	    	perror(COM1);
	    	exit(-1);
  	}
	printf("finish opening com1 \n");
	tcgetattr(fd,&newtio);    
	bzero(&newtio,sizeof(newtio)); 
	//无奇偶校验8位 
	newtio.c_cflag &= ~CSIZE; 
	newtio.c_cflag |= CS8;
	newtio.c_cflag &= ~PARENB;   /* Clear parity enable */
  	newtio.c_iflag &= ~INPCK;     /* Enable parity checking */ 
	newtio.c_cflag &= ~CSTOPB;   //停止位1位
	newtio.c_cc[VTIME] = 0;   
	newtio.c_cc[VMIN] = 0;
	newtio.c_cflag   |=   (CLOCAL|CREAD);
	newtio.c_oflag |= OPOST;
	newtio.c_iflag   &= ~(IXON|IXOFF|IXANY);       
	             
 	cfsetispeed(&newtio,BAUDRATE);  
 	cfsetospeed(&newtio,BAUDRATE);  
 	tcflush(fd,   TCIFLUSH);
 	if (tcsetattr(fd,TCSANOW,&newtio) != 0)  
	{
		perror("SetupSerial 1"); 
	 	return -1; 
 	}  
	return 0;
}