I am trying read and write to/from a USB scanner to extend the functionality of sane a bit. I am able to view the device information and endpoints fairly easily with the following code:

my $usb = Device::USB->new();
my $dev = $usb->find_device( VENDOR, PRODUCT );
print Dumper $dev;
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My problem is that I cannot quite figure out how to provide appropriate parameters for the interrupt_read, interrupt_write, bulk_read and bulk_write methods.

For example, the documentation for interrupt_write provides:

    interrupt_write - Perform a interrupt write request to the specifi
+ed endpoint.
         ep - The number of the endpoint to write
    bytes
         Buffer - Buffer from which to write the requested data.
         timeout - Maximum time to wait (in milliseconds)
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Is 'ep' the full bEndpointAddress or just its lower 3 bits. How do I set up Buffer? Is that an array reference?

Could someone please provide some sample perl code that performs a read or write using Device::USB (or point me to a website)?

Thanks