device identification

[Omer Ihsan]

i have installed pyusb now and run the sample usbenum.py....i have 3
usb ports on my PC but the results show 6 outputs to
dev.filename..they are numbers like 001 or 005 etc.... and they
changed when i plugged in devices...(i am no good with the usb
standards)....i just want to identify each device/port... what
parameter in the example would help me....

 

[Omer Ihsan]

i have installed pyusb now and run the sample usbenum.py....i have 3
usb ports on my PC but the results show 6 outputs to
dev.filename..they are numbers like 001 or 005 etc.... and they
changed when i plugged in devices...(i am no good with the usb
standards)....i just want to identify each device/port... what
parameter in the example would help me....

You can't identify the ports.[1]  What good would it do you?  The ports on
your PC are not numbered.

You certainly CAN identify the devices, by their VID and PID (or idVendor
and idProduct).  You identify by function, not by location.  When you plug
in a USB drive, you don't want to worry about where it's plugged in.
===
[1]: OK, technically, it is not impossible to identify the port numbers,
but it is quite tedious.  You need to chase through the sysfs expansion of
your buses hub/port tree and find a match for your device.  It's not worth
the trouble.

VID and PID is fair enough. now what i want is that i have a threaded
code that threads two functions to run at the same time. i want each
function to run seperate devices. the problem is if it doesnt identify
the attached devices it might run the code on a single device which
isnt what is required.
how will i be able to run a code on a device of my choice???....you
can leave away the threading part for now.