Windows Serial programming
I need to program some software to be able to send and receive serial msgs. I've looked at a lot of places on the net, and on MSDN, and here is some code i got from most places on the net.
Code:
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <commdlg.h>
//#include <windef.h>
int nread,nwrite;
void main()
{
HANDLE hSerial;
COMMTIMEOUTS timeouts;
COMMCONFIG dcbSerialParams;
char *words, *buffRead, *buffWrite;
DWORD dwBytesWritten, dwBytesRead;
hSerial = CreateFile("COM9",GENERIC_READ | GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
if ( hSerial == INVALID_HANDLE_VALUE)
{
if (GetLastError() == ERROR_FILE_NOT_FOUND)
{
printf(" serial port does not exist \n");
}
printf(" some other error occured. Inform user.\n");
}
//DCB dcbSerialParams ;
//GetCommState( hSerial, &dcbSerialParams.dcb);
if (!GetCommState(hSerial, &dcbSerialParams.dcb))
{
printf("error getting state \n");
}
dcbSerialParams.dcb.DCBlength = sizeof(dcbSerialParams.dcb);
dcbSerialParams.dcb.BaudRate = CBR_9600;
dcbSerialParams.dcb.ByteSize = 8;
dcbSerialParams.dcb.StopBits = ONESTOPBIT;
dcbSerialParams.dcb.Parity = NOPARITY;
dcbSerialParams.dcb.fBinary = TRUE;
dcbSerialParams.dcb.fDtrControl = DTR_CONTROL_DISABLE;
dcbSerialParams.dcb.fRtsControl = RTS_CONTROL_DISABLE;
dcbSerialParams.dcb.fOutxCtsFlow = FALSE;
dcbSerialParams.dcb.fOutxDsrFlow = FALSE;
dcbSerialParams.dcb.fDsrSensitivity= FALSE;
dcbSerialParams.dcb.fAbortOnError = TRUE;
if (!SetCommState(hSerial, &dcbSerialParams.dcb))
{
printf(" error setting serial port state \n");
}
GetCommTimeouts(hSerial,&timeouts);
//COMMTIMEOUTS timeouts = {0};
timeouts.ReadIntervalTimeout = 50;
timeouts.ReadTotalTimeoutConstant = 50;
timeouts.ReadTotalTimeoutMultiplier = 10;
timeouts.WriteTotalTimeoutConstant = 50;
timeouts.WriteTotalTimeoutMultiplier= 10;
if(!SetCommTimeouts(hSerial, &timeouts))
{
printf("error setting port state \n");
}
//****************Write Operation*********************//
words = "This is a string to be written to serial port COM1";
nwrite = strlen(words);
buffWrite = words;
dwBytesWritten = 0;
if (!WriteFile(hSerial, buffWrite, nwrite, &dwBytesWritten, NULL))
{
printf("error writing to output buffer \n");
}
//printf("Data written to write buffer is \n %s \n",buffWrite);
//***************Read Operation******************//
//buffRead = 0;
dwBytesRead = 0;
nread = strlen(words);
if (!ReadFile(hSerial, buffRead, nread, &dwBytesRead, NULL))
{
printf("error reading from input buffer \n");
}
printf("Data read from read buffer is \n %s \n",buffRead);
CloseHandle(hSerial);
}
Then I found this while searching the forums.
RS-232 for Linux and WIN32
Its a library for Linux and Win32 RS-232. Even with that I cant open a serial port and I get an error. I've tested the port with hyperterminal and even restarted my PC thinking that hyperterminal didnt close the port properly. I'm using a USB-to-serial adapter and it comes up as a serial port in device manager.
I am doing this all on Win7x64. Is that the problem? But all the software compiles perfectly. It just doesnt seem to open the port on my software, either using the code above, or the libraries.
EDIT: My USB-to-serial adapter is COM9, and my Arduino board is COM6. I just plugged in the Arduino board, and the software cant even open COM6.
