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

void dump(const unsigned char *data_buffer, const unsigned int length) {
	unsigned char byte;
	unsigned int i, j;
	for (i = 0; i < length; i++) {
		byte = data_buffer[i];
		printf("%02x ", data_buffer[i]);  // display byte in hex
		if (((i % 16) == 15) || (i == length - 1)) {
			for (j = 0; j < 15 - (i % 16); j++)
				printf("   ");
			printf("| ");
			for (j = (i - (i % 16)); j <= i; j++) {  // display printable bytes from line
				byte = data_buffer[j];
				if ((byte > 31) && (byte < 127)) // outside printable char range
					printf("%c", byte);
				else
					printf(".");
			}
			printf("\n"); // end of the dump line (each line 16 bytes)
		} // end if
	} // end for
}
void PrintAPIError(const char *msg, DWORD err)
{
	if (msg)
		fprintf(stderr, "%s%d\n", msg, err);

	LPVOID lpMsgBuf;

	FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER |
		FORMAT_MESSAGE_FROM_SYSTEM |
		FORMAT_MESSAGE_IGNORE_INSERTS,
		NULL,
		GetLastError(),
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
		(LPTSTR)&lpMsgBuf,
		0,
		NULL);

	fprintf(stderr, "Win API Last Error: %s", (char *)lpMsgBuf);
	LocalFree(lpMsgBuf);
}
int ReadByte(char *Port,  int BaudRate, int ByteSize,int Parity,int StopBits) 
{ 
 DCB dcb; 
 int retVal; 
 BYTE Byte;  
 DWORD dwBytesTransferred; 
 DWORD dwCommModemStatus=0; 
 const char* DRV_PATH = "\\\\.\\";
 char portName[32];
 strcpy(portName, DRV_PATH);
 strncat(portName, Port, 6);

 HANDLE hPort = CreateFile(portName,GENERIC_READ, 
	0, 
	NULL, 
	OPEN_EXISTING, 
	0, 
	NULL 
 ); 
 if (INVALID_HANDLE_VALUE == hPort) {
	PrintAPIError("Error on CreateFile()!!!\n", GetLastError());
	return 0; 
 }
 if (!GetCommState(hPort,&dcb)) {
	PrintAPIError("Error on GetCommState()!!!\n", GetLastError());
	return 0; 
 }
 dcb.BaudRate = BaudRate;   //9600 Baud   
 dcb.ByteSize = ByteSize;    //8 data bits   
 dcb.Parity = Parity;   //no parity   
 dcb.StopBits = StopBits;  //1 stop 

 if (!SetCommState(hPort,&dcb)) {
  fprintf(stderr,"Error on SetCommState()!!!\n");
  return 0; 
 }
 SetCommMask (hPort, EV_RXCHAR | EV_ERR);  //receive character event   
 WaitCommEvent (hPort, &dwCommModemStatus, 0);  //wait for character 

 while (dwCommModemStatus & EV_RXCHAR)    {
  	ReadFile (hPort, &Byte, 1, &dwBytesTransferred, 0); //read 1  
	printf("%c",Byte);
	//dump(&Byte,sizeof(Byte));

 }
 retVal = Byte;  
 CloseHandle(hPort); 
 return retVal; 
}

int main(int argc, char *argv[])
{
 char *port="COM17";
 ReadByte(port, CBR_9600, 8, NOPARITY, ONESTOPBIT);
	return 0;
}