Re: [Pyusb-users] From libusbJava to pyusb

[Henning S. <h.s...@go...>]

Hi,

yes. Found the error. For sure the value is the "instruction" passed to the device - right?
Now it works fine, cool!

Don't know why i misunderstood that. 
Thank you a lot for helping!

Regards,

Henning

 


Am 18.01.2010 um 12:07 schrieb Wander Lairson:

> No, no... I am asking what does this value mean for your device,
> because as far as I know, you should send it as the value parameter in
> the controlMsg method... :)
> 
> 2010/1/18 Henning Spille <h.s...@go...>:
>> Hi there,
>> 
>> actually i do not really know what that value stands for. In the libUsbJava doc
>> (found here: http://libusbjava.sourceforge.net/wp/res/doc/ch/ntb/usb/LibusbJava.html#usb_control_msg%28long,%20int,%20int,%20int,%20int,%20byte[],%20int,%20int%29 )
>> it is named "value" - well, got no idea what it does mean.
>> 
>> '0x03 << 8 | var' means :0x08 shift by 8,  bitwise or var'
>> 
>> Does it help?
>> 
>> Greetings from Germany,
>> 
>> Henning
>> 
>> 
>> 
>> 
>> Am 18.01.2010 um 00:25 schrieb Wander Lairson:
>> 
>>> What does this expression mean: (0x03 << 8) | var ? I could not see it
>>> in the Python code...
>>> 
>>> Wander
>>> 
>>> 2010/1/17 Henning Spille <h.s...@go...>:
>>>> Hi there,
>>>> 
>>>> i'm trying to use this multi-plug (http://www.nw-s.net/images/sispm.jpg) with pyusb. I already used it form libusbJava which is based on the libusb from linux.
>>>> As it was no problem for me to get it working in java, i'm struggling with python. Well, i'm new to python (actually these are my first few lines of code) but i guessed it is more an pyusb related problem - caused by me.
>>>> 
>>>> I hoped i could convert (manually for sure) the code from libusbJava to pyusb, but it does not work - yet. I attached some lines of code, dmesg output and lsusb --verbose info, but i don't know if it is necessary. Please can someone have a look at the controlMsg translation:
>>>> 
>>>> Java Code:
>>>> 
>>>> int reqtype = 0x21;
>>>> // USB_DIR_OUT + USB_TYPE_CLASS +
>>>> // USB_RECIP_INTERFACE /*request type*/
>>>> int request = 0x09; // writing
>>>> byte var = (byte) (3 * plugNumber);
>>>> int index = 0;
>>>> byte _on = 0x03;
>>>> byte _off = 0x00;
>>>> switchTo = _on;
>>>> byte buffer[] = { var, switchTo };
>>>> int timeout = 250;
>>>> int size = 2;
>>>> if (LibusbJava.usb_control_msg(handle, reqtype, request, (0x03 << 8)
>>>>                                | var, index, buffer, size, timeout) < 0)  .....
>>>> 
>>>> My pyUsb Translation:
>>>> 
>>>> 
>>>> on = 0x03
>>>> off = 0x00
>>>> timeout = 250
>>>> try:
>>>>   print "Trying to switch"
>>>>   var = (3 * plugNumber)
>>>>   reqBuffer = [0] * 2
>>>>   reqBuffer[0] = var
>>>>   reqBuffer[1] = off
>>>>   print "Bytes to write: " + str(reqBuffer)
>>>>   written = handle.controlMsg(0x21, 0x09, reqBuffer,  value=0, index=0, timeout=250)
>>>>   print "Bytes written: " + str(written)
>>>> except Exception, err:
>>>>   print >> sys.stderr, err
>>>>   handle, device = None, None
>>>> 
>>>> 
>>>> 
>>>> The code works, no error in dmesg or elsewhere, but nothing happends at the device - so i guess there is something wrong somewhere. Can i somehow debug the communication?
>>>> 
>>>> Would be nice if someone has some minutes to help me,
>>>> 
>>>> Regards,
>>>> 
>>>> Henning
>>>> ------------------------------------------------------------------------------
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>>>> 
>>>> 
>>> 
>>> ------------------------------------------------------------------------------
>>> Throughout its 18-year history, RSA Conference consistently attracts the
>>> world's best and brightest in the field, creating opportunities for Conference
>>> attendees to learn about information security's most important issues through
>>> interactions with peers, luminaries and emerging and established companies.
>>> http://p.sf.net/sfu/rsaconf-dev2dev
>>> _______________________________________________
>>> Pyusb-users mailing list
>>> Pyu...@li...
>>> https://lists.sourceforge.net/lists/listinfo/pyusb-users
>> 
>> 
> 
> ------------------------------------------------------------------------------
> Throughout its 18-year history, RSA Conference consistently attracts the
> world's best and brightest in the field, creating opportunities for Conference
> attendees to learn about information security's most important issues through
> interactions with peers, luminaries and emerging and established companies.
> http://p.sf.net/sfu/rsaconf-dev2dev
> _______________________________________________
> Pyusb-users mailing list
> Pyu...@li...
> https://lists.sourceforge.net/lists/listinfo/pyusb-users