Linux下串口编程入门（二）

/**
*@brief  设置串口通信速率
*@param  fd     类型 int  打开串口的文件句柄
*@param  speed  类型 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   设置串口数据位，停止位和效验位
*@param  fd     类型  int  打开的串口文件句柄
*@param  databits 类型  int 数据位   取值 为 7 或者8
*@param  stopbits 类型  int 停止位   取值为 1 或者2
*@param  parity  类型  int  效验类型 取值为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) /*设置数据位数*/
{   
case 7:
options.c_cflag |= CS7; 
break;
case 8:     
options.c_cflag |= CS8;
break;   
default:    
fprintf(stderr,"Unsupported data sizen"); 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); /* 设置为奇效验*/  
options.c_iflag |= INPCK;             /* Disnable parity checking */ 
break;  
case 'e':  
case 'E':   
options.c_cflag |= PARENB;     /* Enable parity */    
options.c_cflag &= ~PARODD;   /* 转换为偶效验*/     
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 parityn");    
return (FALSE);  
}  
/* 设置停止位*/  
switch (stopbits)
{   
case 1:    
options.c_cflag &= ~CSTOPB;  
break;  
case 2:    
options.c_cflag |= CSTOPB;  
   break;
default:    
 fprintf(stderr,"Unsupported stop bitsn");  
 return (FALSE); 
} 
/* Set input parity option */ 
if (parity != 'n')   
options.c_iflag |= INPCK; 
tcflush(fd,TCIFLUSH);
options.c_cc[VTIME] = 150; /* 设置超时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*/