#include     <stdio.h>      /*標準輸入輸出定義*/#include     <stdlib.h>     /*標準函數(shù)庫定義*/#include     <unistd.h>     /*Unix標準函數(shù)定義*/#include     <sys/types.h>  /**/#include     <sys/stat.h>   /**/#include     <fcntl.h>      /*文件控制定義*/#include     <termios.h>    /*PPSIX終端控制定義*/#include     <errno.h>      /*錯誤號定義*/#define      TRUE   1#define      FALSE  0/***@brief  設置串口通信速率*@param  fd     類型 int  打開串口的文件句柄*@param  speed  類型 int  串口速度*@return  void*/int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,	    B38400, B19200, B9600, B4800, B2400, B1200, B300, };int name_arr[] = {38400,  19200,  9600,  4800,  2400,  1200,  300,	    38400,  19200,  9600, 4800, 2400, 1200,  300, };void set_speed(int fd, int speed){  int   i;  int   status;  struct termios   Opt;  tcgetattr(fd, &Opt);  for ( i= 0;  i < sizeof(speed_arr) / sizeof(int);  i++)   {   	if  (speed == name_arr[i])   	{   	    tcflush(fd, TCIOFLUSH);    	cfsetispeed(&Opt, speed_arr[i]);    	cfsetospeed(&Opt, speed_arr[i]);    	status = tcsetattr(fd, TCSANOW, &Opt);    	if  (status != 0)            perror("tcsetattr fd1");     	return;     	}   tcflush(fd,TCIOFLUSH);   }}/***@brief   設置串口數(shù)據(jù)位，停止位和效驗位*@param  fd     類型  int  打開的串口文件句柄**@param  databits 類型  int 數(shù)據(jù)位   取值 為 7 或者8**@param  stopbits 類型  int 停止位   取值為 1 或者2**@param  parity  類型  int  效驗類型 取值為N,E,O,,S*/int set_Parity(int fd,int databits,int stopbits,int parity){	struct termios options; if  ( tcgetattr( fd,&options)  !=  0)  {  	perror("SetupSerial 1");  	return(FALSE);  }  options.c_cflag &= ~CSIZE;  switch (databits) /*設置數(shù)據(jù)位數(shù)*/  {  	case 7:  		options.c_cflag |= CS7;  		break;  	case 8:		options.c_cflag |= CS8;		break;	default:		fprintf(stderr,"Unsupported data size\n");		return (FALSE);	}  switch (parity)  	{  	case 'n':	case 'N':		options.c_cflag &= ~PARENB;   /* Clear parity enable */		options.c_iflag &= ~INPCK;     /* Enable parity checking */		break;	case 'o':	case 'O':		options.c_cflag |= (PARODD | PARENB);  /* 設置為奇效驗*/ 		options.c_iflag |= INPCK;             /* Disnable parity checking */		break;	case 'e':	case 'E':		options.c_cflag |= PARENB;     /* Enable parity */		options.c_cflag &= ~PARODD;   /* 轉換為偶效驗*/  		options.c_iflag |= INPCK;       /* Disnable parity checking */		break;	case 'S':	case 's':  /*as no parity*/		options.c_cflag &= ~PARENB;		options.c_cflag &= ~CSTOPB;		break;	default:		fprintf(stderr,"Unsupported parity\n");		return (FALSE);		}  	/* 設置停止位*/     	switch (stopbits)  	{  	case 1:  		options.c_cflag &= ~CSTOPB;		break;	case 2:		options.c_cflag |= CSTOPB;		break;	default:		fprintf(stderr,"Unsupported stop bits\n");		return (FALSE);	}  	/* Set input parity option */  	if (parity != 'n')  		options.c_iflag |= INPCK;    	options.c_cc[VTIME] = 150; // 15 seconds    	options.c_cc[VMIN] = 0;  	tcflush(fd,TCIFLUSH); /* Update the options and do it NOW */  	if (tcsetattr(fd,TCSANOW,&options) != 0)  	{  		perror("SetupSerial 3");		return (FALSE);	}  	return (TRUE);}/***@breif 打開串口*/int OpenDev(char *Dev){	int	fd = open( Dev, O_RDWR );         //| O_NOCTTY | O_NDELAY	if (-1 == fd)	{ 		/*設置數(shù)據(jù)位數(shù)*/		perror("Can't Open Serial Port");		return -1;	}	else		return fd;}/***@breif 	main()*/int main(int argc, char **argv){	int fd;	int nread;	char buff[512];	char *dev ="/dev/ttyS0";	fd = OpenDev(dev);	printf("please enter any data to the ttyS0, Enter key to confirm\n");	if (fd>0)    		set_speed(fd,115200);	else	{		printf("Can't Open Serial Port!\n");		exit(0);	}  	if (set_Parity(fd,8,1,'N')== FALSE)  	{    		printf("Set Parity Error\n");    		exit(1);  	}  	while(1)  	{   		while((nread = read(fd,buff,512))>0)   		{      			printf("\nLen %d\n",nread);      			buff[nread+1]='\0';      			printf("\n%s",buff);   	 	}  	}    	//close(fd);    	//exit(0);}