AN197 Silicon_Laboratories, AN197 Datasheet - Page 10

• Manufacturer Part Number: AN197
• Description: Serial Communications Guide FOR THE Cp210x
• Manufacturer: Silicon_Laboratories

AN197
}
7.3. Sample Program to Retrieve a CP210x COM Port
Included in the AN197SW.zip is a directory named "CP210xPortNumExample" that contains the source code and
executables for a Visual Studio project that makes use of these functions. In the program, the number of CP210x
devices are found and then for each one a port number is retrieved for it and listed in the edit box. (This program
also makes use of the CP210xManufacturing.DLL to find the VID, PID, and serial number on a device. The use of
this DLL is defined in more detail in "AN144: CP210x Device Customization Guide".)
10
}
RegCloseKey(HKEY_LOCAL_MACHINE);
// Return the number of the port the device is connected too
return portNum;
// If we need to make the call again, then decrement the serial index so we can
// accessit the next time through the loop
if (ERROR_MORE_DATA == status)
// Otherwise, the call is a success, and we can compare the portString from the
// key to the port string that we want, if they match then retrieve the port
else if (ERROR_SUCCESS == status)
{
}
// Increment the serial index
serialIndex++;
serKeyString.Format("Enum\\SLABCR\\guid\\%.4d", serialIndex);
// Make sure to close all open keys for cleanup
RegCloseKey(tmpKey);
serialIndex--;
if (portString == portKeyString)
{
if (ERROR_SUCCESS == RegQueryValueEx(tmpKey, "Portname", NULL, &valtype,
}
{
}
// When we obtain this key, it will be in string format of
// "COMXX" where XX is the port. Simply make the first three
// elements of the string 0, and call the atoi function to obtain
// the number of the port.
portString[0] = '0';
portString[1] = '0';
portString[2] = '0';
portNum = atoi(portString);
(unsigned char *)portString, &length))
Rev. 0.6