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...Let me post a couple of lines that I used this week while working with an external DLL that needed C pointers. I only barely understand it at this point because it is new to me, from a friend, and I haven't worked in C in 10 years, but it worked and may lead you in the right direction.
The DLL expected C pointers for input and output to it's functions.
from ctypes import *
Because he's using ctypes.
ExternalLib = windll.LoadLibrary("LibName.dll")
To give me access to the DLL functions.
tmpStr = create_string_buffer(256)
I'm assuming this is a ctypes function that creates a C string pointer.
inx = c_double(1000.00)
This DLL works with coordinates, I'm going to pass a double pointer into one of the functions so must declare it as such.
ExternalLib.SetXIn(inx)
SetXIn() is one of the libraries functions so I'm passing in the c double pointer which I set above.
ExternalLib.GetXOut.restype = c_double
As I understand this (which I really don't) The GetXOut will be returning a pointer to a C double so I have to declare it as such.
outx = ExternalLib.GetXOut()
Then make the call which now give me a regular double stored in python.
I also read a bit of the python Ctypes Tutorial, though only enough to get a basic understanding for now (which is probably obvious).
