1. 程式人生 > >linux下串列埠程式設計設定函式---------set_opt(fd1,115200,8,'N'1)--------------------

linux下串列埠程式設計設定函式---------set_opt(fd1,115200,8,'N'1)--------------------

open /dev/ttys0, 裝置檔案之後,得到檔案描述符, 對串列埠進行設定。

/**
*串列埠設定函式:例(fd1, 115200, 8, 'N', 1);
*引數:
*fd:串列埠裝置節點
*nSpeed:波特率
*nBits:資料位
*nEvent:校驗位
*nStop:停止位
*返回值:成功 -- 0
*		 失敗 -- -1
*/
int set_opt(int fd,int nSpeed, int nBits, char nEvent, int nStop)
{
	struct termios newtio,oldtio;
	if  ( tcgetattr( fd,&oldtio)  !=  0) { 
		perror("SetupSerial 1");
		return -1;
	}
	bzero( &newtio, sizeof( newtio ) );
	newtio.c_cflag  |=  CLOCAL | CREAD;
	newtio.c_cflag &= ~CSIZE;

	switch( nBits )
	{
	case 7:
		newtio.c_cflag |= CS7;
		break;
	case 8:
		newtio.c_cflag |= CS8;
		break;
	}

	switch( nEvent )
	{
	case 'O':
		newtio.c_cflag |= PARENB;
		newtio.c_cflag |= PARODD;
		newtio.c_iflag |= (INPCK | ISTRIP);
		break;
	case 'E': 
		newtio.c_iflag |= (INPCK | ISTRIP);
		newtio.c_cflag |= PARENB;
		newtio.c_cflag &= ~PARODD;
		break;
	case 'N':  
		newtio.c_cflag &= ~PARENB;
		break;
	}

	switch( nSpeed )
	{
	case 2400:
		cfsetispeed(&newtio, B2400);
		cfsetospeed(&newtio, B2400);
		break;
	case 4800:
		cfsetispeed(&newtio, B4800);
		cfsetospeed(&newtio, B4800);
		break;
	case 9600:
		cfsetispeed(&newtio, B9600);
		cfsetospeed(&newtio, B9600);
		break;
	case 115200:
		cfsetispeed(&newtio, B115200);
		cfsetospeed(&newtio, B115200);
		break;
	case 460800:
		cfsetispeed(&newtio, B460800);
		cfsetospeed(&newtio, B460800);
		break;
	default:
		cfsetispeed(&newtio, B9600);
		cfsetospeed(&newtio, B9600);
		break;
	}
	if( nStop == 1 )
		newtio.c_cflag &=  ~CSTOPB;
	else if ( nStop == 2 )
	newtio.c_cflag |=  CSTOPB;
	newtio.c_cc[VTIME]  = 0;
	newtio.c_cc[VMIN] = 0;
	tcflush(fd,TCIFLUSH);
	if((tcsetattr(fd,TCSANOW,&newtio))!=0)
	{
		perror("com set error");
		return -1;
	}
//	printf("set done!\n\r");
	return 0;
}