Sending AT commands to USR modem in C - c

Question

I was wondering if any of you know what I'm doing wrong here? So I have this program in C, that sends AT commands to a modem. These commands have been tested on hyperterminal and work fine, but when sendind them through the modem I get, first, and "OK" for the first "AT" command, which is good, but then, upon sending the next command, the modem answers with "AT+CC"...which I have no idea what it means. Any help is appreciated.
Source:
void sendSMS(const char* port, const char* number, const char* baud)
{
HANDLE hComm;
DCB dcb;
BOOL fSuccess;
hComm = CreateFile(port, //port name
GENERIC_READ | GENERIC_WRITE, //Read/Write
0, // No Sharing
NULL, // No Security
OPEN_EXISTING,// Open existing port only
0, // Non Overlapped I/O
NULL); // Null for Comm Devices
if (hComm == INVALID_HANDLE_VALUE)
{
printf("ERROR: Cannot open serial port\r\n");
return;
}
else
printf("STATUS: Serial port opened\r\n");
// Configure PORT
// Initialize the DCB structure.
SecureZeroMemory(&dcb, sizeof(DCB));
dcb.DCBlength = sizeof(DCB);
// Build on the current configuration by first retrieving all current
// settings.
fSuccess = GetCommState(hComm, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("GetCommState failed with error %d.\n", GetLastError());
return;
}
// Fill in some DCB values and set the com state:
// 57,600 bps, 8 data bits, no parity, and 1 stop bit.
dcb.BaudRate = atoi(baud); // baud rate
dcb.ByteSize = 8; // data size, xmit and rcv
dcb.Parity = NOPARITY; // parity bit
dcb.StopBits = ONESTOPBIT; // stop bit
dcb.fOutxCtsFlow = FALSE;
dcb.fOutxDsrFlow = FALSE;
dcb.fOutX = FALSE;
fSuccess = SetCommState(hComm, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("SetCommState failed with error %d.\n", GetLastError());
return;
}
// Get the comm config again.
fSuccess = GetCommState(hComm, &dcb);
if (!fSuccess)
{
// Handle the error.
printf("GetCommState failed with error %d.\n", GetLastError());
return;
}
// End Config
sendATCommands(hComm, number, "This is NOT a test.");
CloseHandle(hComm);//Closing the Serial Port
}
void sendATCommands(HANDLE hComm, const char* number, const char message[])
{
char str[256];
if (!writeToPort(hComm, "AT\r\n")) //Hello modem
return;
if (!readFromPort(hComm)) // Must be OK
return;
if (!writeToPort(hComm, "AT+CMGF=1\r\n")) //Modem, prepare to send text messages
return;
if (!readFromPort(hComm)) // Must be OK again
return;
memset(str, 0, 256);
strcpy_s(str, "AT+CMGS=\"");
strcat_s(str, 256, number);
strcat_s(str, 256, "\"\r\n");
if (!writeToPort(hComm, str)) //Modem, here's the number to send the message to
return;
if (!readFromPort(hComm)) // Must be ">"
return;
memset(str, 0, 256);
strcpy_s(str, message);
strcat_s(str, 256, "^Z");
if (!writeToPort(hComm, str)) //Modem, communicate this to the number I gave you.
return;
if (!readFromPort(hComm)) // Must be CMGS: ##
return;
}
int writeToPort(HANDLE hComm, const char lpBuffer[])
{
DWORD dNoOFBytestoWrite; // No of bytes to write into the port
DWORD dNoOfBytesWritten = 0; // No of bytes written to the port
dNoOFBytestoWrite = sizeof(lpBuffer);
int Status = WriteFile(hComm, // Handle to the Serial port
lpBuffer, // Data to be written to the port
dNoOFBytestoWrite, //No of bytes to write
&dNoOfBytesWritten, //Bytes written
NULL);
if (Status == FALSE)
{
printf("ERROR: Cannot write to serial port\r\n");
}
else
printf("STATUS: Command %s \n written to port.\r\n", lpBuffer);
return Status;
}
int readFromPort(HANDLE hComm)
{
char TempChar; //Temporary character used for reading
char SerialBuffer[256];//Buffer for storing Rxed Data
DWORD NoBytesRead = 0;
int i = 0;
int status;
memset(SerialBuffer, 0, 256);
printf("STATUS: Waiting response...\r\n");
do
{
status = ReadFile(hComm, //Handle of the Serial port
&TempChar, //Temporary character
sizeof(TempChar),//Size of TempChar
&NoBytesRead, //Number of bytes read
NULL);
if (!status)
{
printf("ERROR: Cannot read from serial port\r\n");
break;
}
SerialBuffer[i] = TempChar;// Store Tempchar into buffer
i++;
}
while (NoBytesRead > 0);
if (status)
printf("PORT RESPONSE: %s \r\n", SerialBuffer);
return status;
}