C++程序将串口或USB数据输入计算机

/* serrecv.c */
/* Receives and saves a file over a serial port */
/* Last modified: Septemeber 21, 2005 */
/* http://www.gomorgan89.com */


#include <windows.h>
#include <stdio.h>
#include <stdlib.h>


/* Function to print out usage information */
void usage(void);


/* Function to set up the serial port settings with the specified baud rate,
   no parity, and one stop bit */
void set_up_serial_port(HANDLE h, long baud);


/* Function to receive and save file from serial port */
void get_file_from_serial_port(HANDLE h, char *file_name, unsigned long file_length);


int main(int argc, char **argv)
{
 HANDLE serial_port;     /* Handle to the serial port */
 long baud_rate = 9600;    /* Baud rate */
 char port_name[] = "COM1:";   /* Name of serial port */
 unsigned long file_size;   /* Size of file to receive in bytes */
 unsigned long bytes_received;  /* Bytes received from serial port */
 unsigned long file_name_size;  /* Size of file name in bytes */
 char file_name[256];    /* Name of file to receive */


 /* Check command line */
 if (argc == 3)
 {
  /* Read in baud rate */
  if (argv[1][1] != 'b' || sscanf(argv[2], "%ld", &baud_rate) != 1)
  {
   usage();
   exit(0);
  }
 }
 else if (argc != 1)
 {
  usage();
  exit(0);
 }


 /* Open up a handle to the serial port */
 serial_port = CreateFile(port_name, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);


 /* Make sure port was opened */
 if (serial_port == INVALID_HANDLE_VALUE)
 {
  fprintf(stderr, "Error opening port\n");
  CloseHandle(serial_port);
  exit(0);
 }


 /* Set up the serial port */
 set_up_serial_port(serial_port, baud_rate);


 /* Receive file name size from serial port */
 ReadFile(serial_port, (void *)&file_name_size, sizeof(unsigned long), &bytes_received, NULL);
 if (bytes_received != sizeof(unsigned long))
 {
  fprintf(stderr, "Error getting file name size.\n");
  CloseHandle(serial_port);
  exit(0);
 }


 /* Receive file name from serial port */
 ReadFile(serial_port, (void *)file_name, file_name_size, &bytes_received, NULL);
 if (bytes_received != file_name_size)
 {
  fprintf(stderr, "Error retrieving file name.\n");
  CloseHandle(serial_port);
  exit(0);
 }


 /* Append NULL terminator to end of string */
 file_name[bytes_received] = '\0';
 
 /* Receive file size from serial port */
 ReadFile(serial_port, (void *)&file_size, sizeof(unsigned long), &bytes_received, NULL);
 if (bytes_received != sizeof(unsigned long))
 {
  fprintf(stderr, "Error getting file size.\n");
  CloseHandle(serial_port);
  exit(0);
 }


 /* Get the file from the serial port */
 get_file_from_serial_port(serial_port, file_name, file_size);


 /* Print out success information */
 printf("\n%lu bytes successfully received and saved as %s\n", file_size, file_name);


 /* Close handle */
 CloseHandle(serial_port);


 return 0;
}


void usage(void)
{
 fprintf(stderr, "Usage:\n");
 fprintf(stderr, "\tserrecv [-b baud rate]\n");
 fprintf(stderr, "\tDefault baud rate is 9600\n");
 fprintf(stderr, "tSupported baud rates: 1200, 2400, 4800, 9600, 14400, 19200\n");
 return;
}


void set_up_serial_port(HANDLE h, long baud)
{
 DCB properties;   /* Properties of serial port */


 /* Get the properties */
 GetCommState(h, &properties);


 /* Set the baud rate */
 switch(baud)
 {
 case 1200:
  properties.BaudRate = CBR_1200;
  break;
 case 2400:
  properties.BaudRate = CBR_2400;
  break;
 case 4800:
  properties.BaudRate = CBR_4800;
  break;
 case 9600:
  properties.BaudRate = CBR_9600;
  break;
 case 14400:
  properties.BaudRate = CBR_14400;
  break;
 case 19200:
  properties.BaudRate = CBR_19200;
  break;
 case 38400:
  properties.BaudRate = CBR_38400;
  break;
 default:
  fprintf(stderr, "Invalid baud rate: %ld\n", baud);
  usage();
  exit(0);
  break;
 }
 
 /* Set the other properties */
 properties.Parity = NOPARITY;
 properties.ByteSize = 8;
 properties.StopBits = ONESTOPBIT;


 SetCommState(h, &properties);


 return;
}


void get_file_from_serial_port(HANDLE h, char *file_name, unsigned long file_length)
{
 FILE *data_file;      /* File to create */
 unsigned long bytes_left = file_length; /* Bytes left to receive */
 unsigned long bytes_received_total = 0; /* Total bytes received */
 unsigned long bytes_to_receive;   /* Number of bytes to receive */
 unsigned long bytes_received;   /* Number of bytes receive */
 char buffer[200];      /* Buffer to store data */


 /* Open the file */
 data_file = fopen(file_name, "wb");


 /* Quit if file couldn't be opened */
 if (data_file == NULL)
 {
  fprintf(stderr, "Could not create file %s\n", file_name);
  CloseHandle(h);
  exit(0);
 }


 while (1)
 {
  /* Determine how many bytes to read */
  if (bytes_left == 0)
  {
   break;
  }
  else if (bytes_left < 200)
  {
   bytes_to_receive = bytes_left;
  }
  else
  {
   bytes_to_receive = 200;
  }


  /* Receive data over serial cable */
  ReadFile(h, (void *)buffer, bytes_to_receive, &bytes_received, NULL);
  if (bytes_received != bytes_to_receive)
  {
   fprintf(stderr, "Error reading file.\n");
   CloseHandle(h);
   exit(0);
  }


  /* Save buffer to file */
  fwrite((void *)buffer, 1, bytes_received, data_file);
  
  /* Decrement number of bytes left */
  bytes_left -= bytes_received;


  /* Increment number of bytes received */
  bytes_received_total += bytes_received;


  /* Print out progress */
  printf("\r%5lu bytes received.", bytes_received_total);
 }


 fclose(data_file);


 return;
}