ublo

simple windows COM port logger

• 03:30:56 pm on Dec 20, 2011

  
  tags: hobby

  yesterday, i’ve posted my wrapper library for the windows COM port with the promise of posting the actual C program that uses it. to compile it you need mingw (see here my tutorial on how to get it up and running). the program is simple and writes in the text.txt file whatever it receives on the serial interface, but no more than MAXLINES lines (in this case, 10 lines). you need to save the previous code as “serial.h” in the same directory as the code below. then, compile it and that’s it! =)

  ask whatever questions here, and i will answer.

  #include <stdio.h>
  #include <windows.h>
  #include "serial.h"
  // the number of lines read from the serial interface.
  // good for data acquisition for a specified amount of time.
  #define MAXLINES 10
  
  int main (int argc, int ** argv) {
      HANDLE comPort;
      FILE * f;
      char buffer[32];
      unsigned short int readbits = 0;
      unsigned long int lines = 0;
      unsigned short int c;
  
      // my COM port is COM15. be sure to change it accordingly
      if ((comPort = openSerialConsole("\\\\.\\COM15")) == (void *) NULL) {
          printf ("Error: COM Port!\n");
          return 1;
          }
  
      // open the file "text.txt". change it for a different file
      f = fopen ("test.txt", "w+");
  
      // read online MAXLINES lines
      while (lines < MAXLINES) {
          // readbits is the number of bytes read from the COM port
          while ((readbits = readFromSerialConsole(comPort, buffer, 32)) != 0) {
              // a good thing to check that the readbits+1 character marks the end
              // of the string. saves you from "Segmentation fault!" errors
              buffer[readbits] = 0;
  
              // check buffer for ENDL character
              for (c = 0; c<readbits; c++)
                  if (buffer[c] == '\n') {
                      lines++;
                      if (lines == MAXLINES) buffer[c] = 0;
                      }
  
              // output to the standard IO, and
              printf("%s", buffer);
              // to the file
              fprintf(f, "%s", buffer);
              }
          }
  
      // close the file handle
      fclose (f);
  
      // close the COM port
      closeSerialConsole(comPort);
  
      return 0;
      }