Re: [pyusb-users] Reading RFID tag using MTI RU-824 via pylab

[Wander L. C. <wan...@gm...>]

2014-02-11 3:56 GMT-02:00 Setia Budi <boe...@gm...>:
>
> Hi fellows,
> I will try to give further information related to my problem.
>
> I am facing difficulties in order to send USB commands to an RFID reader.
> This is the command reference of the device: https://github.com/mti-rfid/RFID_Explorer
>
> I am working with the MTI RU-824 model.
>
> The manufacturer of the device only provide a driver for Windows (using .Net), but we need to run the device on Linux. That's why I need to write few lines of code in Python as a new "driver".
>
> I am using PyUSB for accessing the device, and this is few lines of my code:
>
> ============================================================================
>
> import usb.core
> import usb.util
> import sys
>
> VENDOR_ID = 0x24e9
> PRODUCT_ID = 0x0824
>
> device = usb.core.find(idVendor=VENDOR_ID, idProduct=PRODUCT_ID)
>
> if device is None:
>     sys.exit("Could not find Id System Barcode Reader.")
> else:
>     print 'Device detected'
>
> device.set_configuration()
>
> cfg = device.get_active_configuration()
> interface_number = cfg[(0, 0)].bInterfaceNumber
> alternate_setting = usb.control.get_interface(device, interface_number)
> usb_interface = usb.util.find_descriptor(
>     cfg, bInterfaceNumber=interface_number,
>     bAlternateSetting=alternate_setting
> )
>
> endpoint_out = usb.util.find_descriptor(
>     usb_interface,
>     # match the first OUT endpoint
>     custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress) == usb.util.ENDPOINT_OUT
> )
>
> endpoint_in = usb.util.find_descriptor(
>     usb_interface,
>     # match the first IN endpoint
>     custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress) == usb.util.ENDPOINT_IN
> )
>
> endpoint_out.write('0x01')
> print endpoint_in.read(len('0x01'), 1000)
>
> =============================================================================
> My question is on the last 2 lines.
> I am using endpoint_out to send a command and endpoint_in to read data from the reader. Am I correct?
>
> The problem is, when I run the code, there is an error message like this:
> usb.core.USBError: [Errno 110] Operation timed out
>
> Anyone can give a clue?

Does this happen on write or read operation?


-- 
Best Regards,
Wander Lairson Costa