UsbStringGetDescriptor

Description

Executes the Standard Device Request that obtains the String Descriptor.

Syntax

ulrc = UsbStringGetDescriptor(Handle,ucIndex,usLanguage,usLength,pucDescriptor)

Parameters

Handle

the Device Handle received from the previous UsbOpen.

ucIndex

the Descriptor Index or 0 to obtain the array of Language Codes.

usLanguage

the appropriate Language Code as to the array of Language Codes.

usLength

the desired number of bytes up to 255 for the whole String Descriptor.

pucDescriptor

the address of the variable to receive the String Descriptor.

Return Code

0x0000 - NO_ERROR

Errors

0x0006 - ERROR_INVALID_HANDLE
0x0008 - ERROR_NOT_ENOUGH_MEMORY
0x0057 - ERROR_INVALID_PARAMETER
0x005F - ERROR_INTERRUPT
0x0122 - ERROR_TOO_MANY_HANDLES
0x0280 - ERROR_TIMEOUT
0x1B58 - USB_NOT_INIT
0x4000 - USB_IORB_REQUEST
0x80XX - USB_IORB_FAILED

Example Code

//Code Snippet - UsbStringGetDescriptor
{
  APIRET ulrc;
  PUCHAR pucDescriptor;
  UCHAR ucDescriptor[255];
  UCHAR ucIndex = 2;
  USHORT usLanguage = 0x0409;
  USHORT usLength = sizeof(ucDescriptor);

  pucDescriptor = &ucDescriptor[0];
  ulrc = UsbStringGetDescriptor(Handle,ucIndex,usLanguage,usLength,pucDescriptor);
  printf("\nUsbStringGetDescriptor - ulrc: 0x%04X (%hu)",ulrc,ulrc);
  if (!ulrc) //success
  {
    int i; printf(" - StringDescriptor:\n");
    for (i=0;i<ucDescriptor[0];i++) printf("%02X",ucDescriptor[i]);
//  for (i=2;i<ucDescriptor[0];i+=2) printf("%c",ucDescriptor[i]);
  }
}