Re: [pyusb-users] error in usb module while write

[bibek c. <bib...@gm...>]

Hello Wander,

I can write into the device. As you said earlier it was a bulk transfer.
I have tried with this code. But the return is an array of zeros.
Does it require a loop or something I am missing.
*
*
*Code*
#!/usr/bin/python
import sys

import usb.core
import usb.util

VENDOR_ID = 0x0dd4
PRODUCT_ID = 0x01a8

device = usb.core.find(idVendor=VENDOR_ID, idProduct=PRODUCT_ID)

if device is None:
    sys.exit("Could not find Printer.")

if device.is_kernel_driver_active(0):
    try:
        device.detach_kernel_driver(0)
    except usb.core.USBError as e:
        sys.exit("Could not detatch kernel driver: %s" % str(e))

try:
    device.set_configuration()
    device.reset()
except usb.core.USBError as e:
    sys.exit("Could not set configuration: %s" % str(e))

################################################
data = []
read_complete = False

print 'data written: ', device.write(2, [0x10])

try:
    data = device.read( 2,6)
except Exception as e:
    print e

print 'data type: ', type(data)
print 'received data: ', data

*Output*
$ sudo python hardware_monitor_printer.py
data written:  1
data type:  <type 'array.array'>
received data:  array('B', [0, 0, 0, 0, 0, 0])

#############################################
As you can see, I want to write '\x10' into the device
and the device is supposed to return the status.

I have a example in C that can monitor the status. But I am
struggling very much in python.

Thanks