[Pyusb-users] From libusbJava to pyusb

[Henning S. <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