Talking to USB devices

[Askold]

Hi All!

I try to communicate with USB devices. I successfully get a device path for calling CreateFile() to communicate with USB device. But I have trouble with calling ReadFile() and WriteFile(). The calling of these functions always end with 5 code error.

I don't understand what I do wrong. Maybe the drivers of my devices just don't allow to communicate with device or I made a mistake in my code.

Please help.

There is my programming code:

void _tmain(int argc, _TCHAR* argv[])
{
	//GUID hidGuid = CLSID_NULL; // Disk Device.
	//CLSIDFromString(L"{53f56307-b6bf-11d0-94f2-00a0c91efb8b}", &hidGuid);

	GUID hidGuid = CLSID_NULL; // Human Interface Device (HID).
	HidD_GetHidGuid(&hidGuid);

	//GUID hidGuid = CLSID_NULL; // USB Device.
	//CLSIDFromString(L"{36FC9E60-C465-11CF-8056-444553540000}", &hidGuid);

	//GUID hidGuid = CLSID_NULL; // USB Raw Device.
	//CLSIDFromString(L"{A5DCBF10-6530-11D2-901F-00C04FB951ED}", &hidGuid);

	HDEVINFO devInfo = SetupDiGetClassDevs(&hidGuid, NULL, NULL, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);

	SP_DEVINFO_DATA devInfoData;
	devInfoData.cbSize = sizeof(SP_DEVINFO_DATA);

	for(int i = 0; SetupDiEnumDeviceInfo(devInfo, i, &devInfoData); i++)
	{
		//printf("Iteration Number: %d\n", i);
		//ShowDeviceProperty(devInfo, devInfoData);

		SP_DEVICE_INTERFACE_DATA devInterfaceData;
		devInterfaceData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);

		for(int j = 0; SetupDiEnumDeviceInterfaces(devInfo, &devInfoData, &hidGuid, j, &devInterfaceData); j++)
		{
			DWORD bufferSize = 0;
			SetupDiGetDeviceInterfaceDetail(devInfo, &devInterfaceData, NULL, 0, &bufferSize, &devInfoData);

			PSP_DEVICE_INTERFACE_DETAIL_DATA pDeviceInterfaceDetailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)malloc(bufferSize);
			pDeviceInterfaceDetailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
			
			SetupDiGetDeviceInterfaceDetail(devInfo, &devInterfaceData, pDeviceInterfaceDetailData, bufferSize, &bufferSize, &devInfoData);

			SECURITY_ATTRIBUTES securityAttributes;
			memset(&securityAttributes, 0, sizeof(SECURITY_ATTRIBUTES));
			securityAttributes.nLength = sizeof(SECURITY_ATTRIBUTES);
			securityAttributes.bInheritHandle = true;

			HANDLE fileHandle = CreateFile(pDeviceInterfaceDetailData->DevicePath, 0, FILE_SHARE_READ|FILE_SHARE_WRITE, 
				&securityAttributes, OPEN_EXISTING, 0, NULL);

			printf("File handle value %d\n", fileHandle);
			if ((int)fileHandle != -1)
			{
				/*HIDP_CAPS Capabilities;
				PHIDP_PREPARSED_DATA PreparsedData;
				HidD_GetPreparsedData(fileHandle, &PreparsedData);
				printf("HidD_GetPreparsedData error: %d\n", GetLastError());
				HidP_GetCaps(PreparsedData, &Capabilities);*/
				

				HIDD_ATTRIBUTES	attributes;
				memset(&attributes, 0, sizeof(HIDD_ATTRIBUTES));
				attributes.Size = sizeof(HIDD_ATTRIBUTES);

				HidD_GetAttributes(fileHandle, &attributes);
				printf("Device attribute: %d, %d, %d\n", attributes.ProductID, attributes.VendorID, attributes.VersionNumber);

				char bufRead[256] = {0};
				DWORD countRead = 0;
				if(!ReadFile(fileHandle, bufRead, 5, &countRead, NULL))
				{
					printf("Reading file error %d\n", GetLastError());
				}
				
				char bufWrite[] = {'7', '8', '9', ' '};
				DWORD countWritten = 0;
				if(!WriteFile(fileHandle, bufWrite, 3, &countWritten, NULL))
				{
					printf("Writing file error %d\n", GetLastError());
				}
			}
			else
			{
				printf("Error code: %d\n", GetLastError());
			}

			free(pDeviceInterfaceDetailData);
		}

		printf("____________________\n");
	}

	SetupDiDestroyDeviceInfoList(devInfo);
}

Thank you much for your consideration.

[Codeplug]

Please use code tags when posting code: http://www.codeguru.com/forum/misc.php?do=bbcode#code
Once you edit your post and re-copy the code with indentation, folks will be more likely to look at it.

Few things I see:
* Check for errors on all API functions.
* Try using NULL instead of the empty securityAttributes.
* Once you do open a device, you typically call HidD_GetAttributes() first thing to see if it's the ProductId/VenderId of the device you intend to work with.
* Second parameter to CreateFile, dwDesiredAccess, is zero (as it typically for HID devices), so don't expect ReadFile/WriteFile to work. You usually just use Hid functions once you get a handle.

gg

[AGGIE]

Hey Askold, did you ever get that code to work ?