#include <stdio.h> /*標准輸入輸出定義*/
#include <stdlib.h> /*標准函數庫定義*/
#include <unistd.h> /*Unix 標准函數定義*/
#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*/
struct termio
{ unsigned short c_iflag; /* 輸入模式標志 */
unsigned short c_oflag; /* 輸出模式標志 */
unsigned short c_cflag; /* 控制模式標志*/
unsigned short c_lflag; /* local mode flags */
unsigned char c_line; /* line discipline */
unsigned char c_cc[NCC]; /* control characters */
};
int speed_arr[] = { B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300};
int name_arr[] = { 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300};
/**
*@brief Set Serial Port BitRate
*@param fd Type : int The File Description of Serial Port
*@param speed Type : int Serial Speed
*@return void
*/
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 fd");
return;
}
tcflush(fd,TCIOFLUSH);
}
}
}
/**
*@brief Set Serial Port Databits, Stopbits and Parity.
*@param fd Type: int The File Description of Serial Port
*@param databits Type: int Databits 7 or 8
*@param stopbits Type: int Stopbits 1 or 2
*@param parity Type: int Parity Type: n,N,e,E,o,O,s,S
*/
int set_Parity(int fd, int databits, int parity, int stopbits)
{
struct termios options;
if ( tcgetattr( fd,&options) != 0)
{
perror("SetupSerial 1");
return(-1);
}
options.c_cflag &= ~CSIZE;
switch (databits) /*Set Datebits*/
{
case 7:
options.c_cflag |= CS7;
break;
case 8:
options.c_cflag |= CS8;
break;
default:
fprintf(stderr,"Unsupported data size\n");
return(-1);
}
switch (parity) /*Set 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); /* Odd Checking*/
options.c_iflag |= INPCK; /* Disnable parity checking */
break;
case 'e':
case 'E':
options.c_cflag |= PARENB; /* Enable parity */
options.c_cflag &= ~PARODD; /* Even Checking*/
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(-1);
}
switch (stopbits) /*Set Stobits*/
{
case 1:
options.c_cflag &= ~CSTOPB;
break;
case 2:
options.c_cflag |= CSTOPB;
break;
default:
fprintf(stderr,"Unsupported stop bits\n");
return(-1);
}
/* Set input parity option */
if (parity != 'n')
options.c_iflag |= INPCK;
/*以下兩句添加后發送方可以不加回車換行，但是read讀取不完整*/
options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); /*Input*/
options.c_oflag &= ~OPOST; /*Output*/
//屏蔽功能： NL(換行)->CR(回車)、CR->NL、忽略輸入回車
options.c_iflag &= ~(INLCR | ICRNL | IGNCR);
options.c_oflag &= ~(ONLCR | OCRNL);
tcflush(fd,TCIFLUSH);
//未設置O_NONBLOCK或O_NDELAY
options.c_cc[VTIME] = 150; /* Timeout in 15 seconds*/
options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
if (tcsetattr(fd,TCSANOW,&options) != 0)
{
perror("SetupSerial 3");
return(-1);
}
return(0);
}
int main(void)
{ char buf[512] = {0}; int nread = 0; char* dev = "/dev/ttyS0"; int fd = open(dev, O_RDWR|O_NOCTTY); if (fd > 0) { printf("Open %s Success!\n", dev); } else { printf("Can't Open %s\n", dev); exit(0); } set_speed(fd, 115200); if(set_Parity(fd, 8, 'N', 1) == -1) { close(fd); exit(-1); } while(1) { if((nread = read(fd,buf,512))>0) { printf("%s",buf); } } close(fd); exit(0); }
