HELP with storing serial port data into txt file

I have a programming which draws a graph for .txt data and other things.

Im trying to make this code take single character inputs from the serial port and store them into a txt file as an integer along with the date and time. I think im ok with the date and time. but im not sure how to change what ive done to save data to a txt file. At the mo it just keeps taking inputs, displaying them and sends out _kbhit's.

Previously i was just manually inputing the data as you can see from the commented code at the top.

I have been tying to overcome this problem for days now so any help welcome. Here is my code, thanks.

Code:

int  GetReadings(int nReadings, int *pReadings)   
{
   	/*int iReadings;

	printf("Enter readings, one at a time.\n");
	
	for(iReadings = 0; iReadings < nReadings; iReadings++){
		printf("Enter readins #%i: ", iReadings+1);
		scanf("%i", pReadings++);
	}
	return nReadings;
	*/
    unsigned char c;
    DCB dcb;
    HANDLE hCom;
    char *pcCommPort;
    int portno;
    int nErrNo;
	DWORD nWritten, nRead;
    COMMTIMEOUTS CommTimeOuts;

// Which port is to be used 1 or 2?
    printf("Which port (1/2)?: ");
    scanf("%d",&portno);
    if(portno == 1)pcCommPort = "COM1";
    else pcCommPort = "COM2";

// "Open" the port and get a handle to it
    hCom = CreateFile( pcCommPort,
					 GENERIC_READ | GENERIC_WRITE,
					 0,    // exclusive-access
                     NULL, // no security attributes
                     OPEN_EXISTING, // comm devices must use OPEN_EXISTING
                     0,    // not overlapped I/O
                     NULL  // must be NULL for comm devices
                     );

    if (hCom == INVALID_HANDLE_VALUE) {
        printf ("CreateFile failed with error %d.\n", GetLastError());
        return 0;
    }

// Get the device control block for the port, check it's OK...
    if (!GetCommState(hCom, &dcb)) {
        printf ("GetCommState failed with error %d.\n", GetLastError());
        return 0;
    }

// ...and adjust the values to baud=9600 bps, 8 data bits, no parity, and 1 stop bit...
    dcb.BaudRate = CBR_9600;     // set the baud rate
    dcb.ByteSize = 8;             // data size, xmit, and rcv
    dcb.Parity = NOPARITY;        // no parity bit
    dcb.StopBits = ONESTOPBIT;    // one stop bit

// ...and write the device control block back.
    if (!SetCommState(hCom, &dcb)) {
        printf ("SetCommState failed with error %d.\n", GetLastError());
        return 0;
    }

// Set up the comm timeouts
    if(!GetCommTimeouts(hCom, &CommTimeOuts)) {
        printf ("GetCommTimeouts failed with error %d.\n", GetLastError());
        return 0;
    }
    CommTimeOuts.ReadIntervalTimeout = MAXDWORD; // This combination of values
    CommTimeOuts.ReadTotalTimeoutConstant = 0;  // ..causes ReadFile to return
    CommTimeOuts.ReadTotalTimeoutConstant = 0;  // ..immediately even if no chars rec'd
    if (!SetCommTimeouts(hCom, &CommTimeOuts)) {
        printf ("SetCommTimeouts failed with error %d.\n", GetLastError());
        return 0;
    }

    printf ("Serial port %s successfully reconfigured.\n", pcCommPort);

    printf("Starting TTY emulator.\n");

// Loop around reading the keyboard and comm port
    while(c != 'X'){
        if(_kbhit()){
            c = _getch();
		        if(WriteFile(hCom, &c, (DWORD)1, &nWritten, NULL) != 0)
                    if((nErrNo = GetLastError()) != ERROR_SUCCESS)
			            printf("\nWriteFile error: %d", GetLastError());   
        }
		if(ReadFile(hCom,&c,(DWORD)1,&nRead,NULL) == 0)
			printf("ReadFile error\n");
        if(nRead > 0)
            putchar(c);
			
    }
	
}

how these 2 functions

Code:

       if(_kbhit()){
            c = _getch();

are concerned with the reading from the com-port?
you should use the correct API functions to read using hCom handle

Originally Posted by vart

how these 2 functions

Code:

       if(_kbhit()){
            c = _getch();

are concerned with the reading from the com-port?
you should use the correct API functions to read using hCom handle

They are not related to reading the comport, but from what I understand of the code, it's a very simple terminal program that reads the console and echoes it to the serial port, reads the comport and echoes to the console.

To trivially write to a file, just open a file using fopen() and then use fputc() next to your putchar(). If you want both input and output to appear in the same file, then use a fputc() next to the WriteFile(hCom, ....) too.

--
Mats