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.spi...@googlemail.com>: >> 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 >> ------------------------------------------------------------------------------ >> 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 >> Pyusb-users@lists.sourceforge.net >> 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 > Pyusb-users@lists.sourceforge.net > 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 Pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
