#include     <stdio.h>      /*標(biāo)準(zhǔn)輸入輸出定義*/
#include     <stdlib.h>     /*標(biāo)準(zhǔn)函數(shù)庫(kù)定義*/
#include     <unistd.h>     /*Unix 標(biāo)準(zhǔn)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(cuò)誤號(hào)定義*/

												
										

												
														int fd;
/*以讀寫方式打開串口*/
fd = open( "/dev/ttyS0", O_RDWR);
if (-1 == fd){ 
/* 不能打開串口一*/ 
perror(" 提示錯(cuò)誤！");
}

												
										

												
														struct termio
{	unsigned short  c_iflag;	/* 輸入模式標(biāo)志 */	
	unsigned short  c_oflag;		/* 輸出模式標(biāo)志 */	
	unsigned short  c_cflag;		/* 控制模式標(biāo)志*/	
	unsigned short  c_lflag;		/* local mode flags */	
	unsigned char  c_line;		    /* line discipline */	
	unsigned char  c_cc[NCC];    /* control characters */
};

												
										

												
														struct  termios Opt;
tcgetattr(fd, &Opt);
cfsetispeed(&Opt,B19200);     /*設(shè)置為19200Bps*/
cfsetospeed(&Opt,B19200);
tcsetattr(fd,TCANOW,&Opt);

												
										

												
														/**
*@brief  設(shè)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(fd1, TCSANOW, &Opt);  
			if  (status != 0) {        
				perror("tcsetattr fd1");  
				return;     
			}    
			tcflush(fd,TCIOFLUSH);   
		}  
	}
}

												
										

												
														/**
*@brief   設(shè)置串口數(shù)據(jù)位，停止位和效驗(yàn)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(yàn)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(shè)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(shè)置為奇效驗(yàn)*/  
		options.c_iflag |= INPCK;             /* Disnable parity checking */ 
		break;  
	case 'e':  
	case 'E':   
		options.c_cflag |= PARENB;     /* Enable parity */    
		options.c_cflag &= ~PARODD;   /* 轉(zhuǎn)換為偶效驗(yàn)*/     
		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(shè)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; 
tcflush(fd,TCIFLUSH);
options.c_cc[VTIME] = 150; /* 設(shè)置超時(shí)15 seconds*/   
options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
if (tcsetattr(fd,TCSANOW,&options) != 0)   
{ 
	perror("SetupSerial 3");   
	return (FALSE);  
} 
return (TRUE);  
}

												
										

												
														options.c_lflag  &= ~(ICANON | ECHO | ECHOE | ISIG);  /*Input*/
options.c_oflag  &= ~OPOST;   /*Output*/

												
										

												
														close(fd);

												
										

												
														/**********************************************************************代碼說(shuō)明：使用串口二測(cè)試的，發(fā)送的數(shù)據(jù)是字符，
但是沒有發(fā)送字符串結(jié)束符號(hào)，所以接收到后，后面加上了結(jié)束符號(hào)。我測(cè)試使用的是單片機(jī)發(fā)送數(shù)據(jù)到第二個(gè)串口，測(cè)試通過。
**********************************************************************/
#define FALSE  -1
#define TRUE   0
/*********************************************************************/
int OpenDev(char *Dev)
{
	int	fd = open( Dev, O_RDWR );         //| O_NOCTTY | O_NDELAY	
	if (-1 == fd)	
	{ 			
		perror("Can't Open Serial Port");
		return -1;		
	}	
	else	
		return fd;
}
int main(int argc, char **argv){
	int fd;
	int nread;
	char buff[512];
	char *dev  = "/dev/ttyS1"; //串口二
	fd = OpenDev(dev);
	set_speed(fd,19200);
	if (set_Parity(fd,8,1,'N') == FALSE)  {
		printf("Set Parity Error\n");
		exit (0);
	}
while (1) //循環(huán)讀取數(shù)據(jù)
{   
	while((nread = read(fd, buff, 512))>0)
	{ 
		printf("\nLen %d\n",nread); 
		buff[nread+1] = '\0';   
		printf( "\n%s", buff);   
	}
}
	//close(fd);  
	// exit (0);
}