串口通信——接收串口数据并处理（C语言）

本文主要内容包含：

 1.接收串口数据程序的编程逻辑示意图；

 2.接收串口数据程序要用到的通用函数模块（可直接引用，无需更改）；

 3.接收串口数据程序的示例。

1.接收串口数据程序的编程逻辑示意图：

2.与串口有关的函数模块及数组（可直接引用到自己的程序中）：

//设置波特率函数会用到的数组
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, };

int OpenDev(char *Dev) //打开串口
{
	int fd = open(Dev,O_RDWR | O_NOCTTY | O_NONBLOCK);
	if(-1 == fd)
	{
		perror("Can't Open Serial Port");
		return -1;
	}
	else
	{
		printf("Open com success!!!!!!!!!!!");
		return fd;
	}
}

void set_speed(int fd, int speed)  //设置波特率
{
  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);
   }
}

int set_Parity(int fd,int databits,int stopbits,int parity)  //设置数据位、奇偶位、停止位等
{
   struct termios options;
 if  ( tcgetattr( fd,&options)  !=  0)
  {
    perror("SetupSerial 1");
    return(0);
  }
  bzero(&options,sizeof(options));
  options.c_cflag |= CLOCAL | CREAD;
  options.c_cflag &= ~CSIZE;
  switch (databits) /*设置数据位*/
  {
    case 7:
        options.c_cflag |= CS7;
        break;
    case 8:
        options.c_cflag |= CS8;
        break;
    default:
        fprintf(stderr,"Unsupported data size\n");
        return (0);
    }
  switch (parity)/*设置校验位*/
    {
    case 'n':
    case 'N':
        options.c_cflag &= ~PARENB;  
        //options.c_iflag &= ~INPCK;    
        break;
    case 'o':
    case 'O':
        options.c_cflag |= (PARODD | PARENB);  
        options.c_iflag |= (INPCK | ISTRIP);            
        break;
    case 'e':
    case 'E':
        options.c_cflag |= PARENB;    
        options.c_cflag &= ~PARODD;  
        options.c_iflag |= (INPCK | ISTRIP);       
        break;
    case 'S':
    case 's':  
        options.c_cflag &= ~PARENB;
        options.c_cflag &= ~CSTOPB;
        break;
    default:
        fprintf(stderr,"Unsupported parity\n");
        return (0);
        }
  switch (stopbits)/*设置停止位*/
    {
    case 1:
        options.c_cflag &= ~CSTOPB;
        break;
    case 2:
        options.c_cflag |= CSTOPB;
        break;
    default:
        fprintf(stderr,"Unsupported stop bits\n");
        return (FALSE);
    }
  if (parity != 'n')
    options.c_iflag |= INPCK;
    options.c_cc[VTIME] = 0; 
    options.c_cc[VMIN] = 0;
  tcflush(fd,TCIFLUSH); 
  if (tcsetattr(fd,TCSANOW,&options) != 0)
    {
        perror("SetupSerial 3");
        return (0);
    }
  return (1);
 }

3.示例：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#define TRUE 1
#define FALSE 0

int analysis(char *buff);
int OpenDev(char *Dev);
void set_speed(int fd, int speed);
int set_Parity(int fd,int databits,int stopbits,int parity);

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, };
int OpenDev(char *Dev)
{
  int fd = open(Dev,O_RDWR | O_NOCTTY | O_NONBLOCK);
  if(-1 == fd)
    {
      perror("Can't Open Serial Port");
      return -1;
    } 
  else 
    {
      printf("Open com success!!!!!!!!!!!");
      return fd;
    }
} 
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);
    }
}
int set_Parity(int fd,int databits,int stopbits,int parity) 
{ 
  struct termios options; 
  if ( tcgetattr( fd,&options) != 0) 
  {
   perror("SetupSerial 1");
   return(FALSE);
 } 
  bzero(&options,sizeof(options)); 
  options.c_cflag |= CLOCAL | CREAD;
 options.c_cflag &= ~CSIZE; 
  switch (databits) 
  { 
    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;
   options.c_iflag &= ~INPCK; 
    break; 
    case 'o':
   case 'O': 
    options.c_cflag |= (PARODD | PARENB);
   options.c_iflag |= (INPCK | ISTRIP); 
    break; 
    case 'e': 
    case 'E': 
    options.c_cflag |= PARENB;
   options.c_cflag &= ~PARODD; 
    options.c_iflag |= (INPCK | ISTRIP); 
    break; 
    case 'S': 
    case 's': 
    options.c_cflag &= ~PARENB; 
    options.c_cflag &= ~CSTOPB;
   break;
   default: fprintf(stderr,"Unsupported parity\n"); 
   return (FALSE); 
  } 
  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); 
    } 
    if (parity != 'n') 
    options.c_iflag |= INPCK; 
    options.c_cc[VTIME] = 0;
   options.c_cc[VMIN] = 0;
   tcflush(fd,TCIFLUSH); 
    if (tcsetattr(fd,TCSANOW,&options) != 0)
   {  
        perror("SetupSerial 3"); 
        return (FALSE);
   } 
    return (TRUE);
}

int analysis (char *buff）
{
  int i;
  char *p；
  p=buff;
  for(i=0;i<255,i++)
    {
      printf("%s ",p[i]);
    }
  return 0;
}

void main(void)
{
  int fd;
  int nread;
  char buff[255];
  char *dev_name = "/dev/ttymxc4";//根据实际情况选择串口
  while(1) 
    {  
      fd = OpenDev(dev_name); //打开串口 

      if(fd>0) 
      set_speed(fd,9600); //设置波特率 
      else 
      { 
         printf("Can't Open Serial Port!\n"); 
         sleep(1);
        continue; 
      } 
  break;
}

if(set_Parity(fd,8,1,'N')==FALSE) //设置校验位 
{
  printf("Set Parity Error\n"); 
  exit(1);
}

while(1) 
  { 
    sleep(3); 
    nread = read(fd,buff,sizeof(buff));
    if((nread>0))
      {		
	printf("Success!\n"); 
       }
    analysis(buff)；
  }
}