C++: Serial interfacing with Arduino - c++

Question

I've been trying to communicate with Arduino through its serial port and with the C++ code below.
The only thing is: it is always returning an invalid_handle_value.
I've looked everywhere, and all people are using kind of the same code... except it's working for them.
P.S: Arduino is on COM15. This code worked with port COM4 (Bluetooth).
The code
#include "SerialClass.h"
Serial::Serial(char *portName)
{
//We're not yet connected
this->connected = false;
//Try to connect to the given port throuh CreateFile
this->hSerial = CreateFile(portName,
/*GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);*/
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
0);
//Check if the connection was successful.
if (this->hSerial==INVALID_HANDLE_VALUE)
{
//If not success full display an Error.
if (GetLastError()==ERROR_FILE_NOT_FOUND){
//Print Error if neccessary
printf("ERROR: Handle was not attached. Reason: %s not available.\n", portName);
}
else
{
printf("ERROR!!!");
}
}
else
{
//If connected we try to set the comm parameters
DCB dcbSerialParams = {0};
//Try to get the current
if (!GetCommState(this->hSerial, &dcbSerialParams))
{
//If impossible, show an error
printf("failed to get current serial parameters!");
}
else
{
//Define serial connection parameters for the arduino board
dcbSerialParams.BaudRate=CBR_9600;
dcbSerialParams.ByteSize=8;
dcbSerialParams.StopBits=ONESTOPBIT;
dcbSerialParams.Parity=NOPARITY;
//Set the parameters and check for their proper application
if (!SetCommState(hSerial, &dcbSerialParams))
{
printf("ALERT: Could not set Serial Port parameters");
}
else
{
//If everything went fine we're connected
this->connected = true;
//We wait 2s as the arduino board will be reseting
Sleep(ARDUINO_WAIT_TIME);
}
}
}
}
Serial::~Serial()
{
//Check if we are connected before trying to disconnect
if (this->connected)
{
//We're no longer connected
this->connected = false;
//Close the serial handler
CloseHandle(this->hSerial);
}
}
int Serial::ReadData(char *buffer, unsigned int nbChar)
{
//Number of bytes we'll have read
DWORD bytesRead;
//Number of bytes we'll really ask to read
unsigned int toRead;
//Use the ClearCommError function to get status info on the Serial port
ClearCommError(this->hSerial, &this->errors, &this->status);
//Check if there is something to read
if (this->status.cbInQue>0)
{
//If there is we check if there is enough data to read the required number
//of characters, if not we'll read only the available characters to prevent
//locking of the application.
if (this->status.cbInQue>nbChar)
{
toRead = nbChar;
}
else
{
toRead = this->status.cbInQue;
}
//Try to read the require number of chars, and return the number of read bytes on success
if (ReadFile(this->hSerial, buffer, toRead, &bytesRead, NULL) && bytesRead != 0)
{
return bytesRead;
}
}
//If nothing has been read, or that an error was detected return -1
return -1;
}
bool Serial::WriteData(char *buffer, unsigned int nbChar)
{
DWORD bytesSend;
//Try to write the buffer on the Serial port
if (!WriteFile(this->hSerial, (void *)buffer, nbChar, &bytesSend, 0))
{
//In case it don't work get comm error and return false
ClearCommError(this->hSerial, &this->errors, &this->status);
return false;
}
else
return true;
}
bool Serial::IsConnected()
{
//Simply return the connection status
return this->connected;
}
int main() {
Serial serial("COM15");
if (serial.IsConnected()){
serial.WriteData("1",1);
printf("\nData sent successfully!\n");
}
system("pause");
return 0;
}

Answer 1

Try using a filename of "\\\\.\\COM15" (see http://support.microsoft.com/kb/115831).