[Libusb-win32-devel] usb_control_msg() returning -1

[Prabhu R <ece...@gm...>]

Hi Guys,

            I tried to use usb_control_msg() for a vendor specific request,
but its returning -1(failure). I have one of my device connected. My code is
given below.
My values for the parameter are the following,
RequestType - 0xc1 (vendor specific request)
Request        - 0x82
Value            - 0
Index             - 0
buffer             - char data[10]
length            - 10
timeout          - 1000

Please provide a suggestion.

Source Code:

#include <stdio.h>

#include "usb.h"

main()

{

int i;

char data[10];

struct usb_bus *bus;

struct usb_device *device;

struct usb_dev_handle *handle;

usb_init();

i = usb_find_busses();

printf("No of busses found = %d\n", i);

i = usb_find_devices();

printf("No of devices found = %d\n", i);

for(bus = usb_get_busses(); bus; bus = bus->next)

{

for(device = bus->devices; device; device = device->next)

{

printf("Starting to open device.....\n");

handle = usb_open(device);

i = usb_control_msg(handle, 0xc1, 0x82, 0, 0, data, 10, 1000);

printf("Return Value of usb_control_msg() = %d", i);

usb_close(handle);

}

}

getch();

}

Output:

No of busses found = 1

No of devices found = 1

Starting to open device.....

Return Value of usb_control_msg() = -1