2012/1/30 bibek chitrakar <bibek.chitra...@gmail.com>:
> Thanks Wander,
> Device is not reset this time. I have removed the reset line.
> But I am not receiving any response from the printer.
> Do I have to delay some time for reading or
> the recieved array is to be manipulated some way.
> There is another code example that is in C and its working fine.
>
> 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()
>> 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
>
>
> The output is still the same.
> Output:
>>
>> # python hardware_monitor_printer.py
>> data written: 1
>> data type: <type 'array.array'>
>> received data: array('B', [0, 0, 0, 0, 0, 0])
>
>
> Device info is:
>>
>> Device:
>>
>> Device class: 0
>> Device sub class: 0
>> Device protocol: 0
>> Max packet size: 64
>> idVendor: 3540
>> idProduct: 424
>> Device Version: 281
>>
>> Configuration: 1
>> Total length: 32
>> selfPowered: 1
>> remoteWakeup: 0
>> maxPower: 4
>> Interface: 0
>> Alternate Setting: 0
>> Interface class: 7
>> Interface sub class: 1
>> Interface protocol: 2
>> Endpoint: 0x81
>> Type: 2
>> Max packet size: 64
>> Interval: 0
>> Endpoint: 0x2
>> Type: 2
>> Max packet size: 64
>> Interval: 0
>
>
> Could you please analyse the situation here....??
>
>From USB spec point of view, it appears there is nothing wrong with
the code, this is a flaw related to specific printer protocol. Try to
delay between the write and read and check if it works. Also, try to
compare line by line with the C counterpart.
--
Best Regards,
Wander Lairson Costa
------------------------------------------------------------------------------
Try before you buy = See our experts in action!
The most comprehensive online learning library for Microsoft developers
is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
Metro Style Apps, more. Free future releases when you subscribe now!
http://p.sf.net/sfu/learndevnow-dev2
_______________________________________________
pyusb-users mailing list
pyusb-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pyusb-users
