i created two C externals pretty close to the tutorial examples from the HOW-TO. Compiling worked but PD didn't recognize the class_setup. I searched a bit and found i had to insert the line "__declspec(dllexport) void classname_setup(void);". After that PD recognizes the object.
The only problem left is that my external isn't properly loaded every time i open a patch containing the object. Sometimes it gets changed to a simple comment. Its saying #X text 100 100 myexternal; in the .pd file, so it seems to happen while saving. It doesn't happen every time but often enough.
Is this related to the line i had to insert? I thought it just changes the way PD handles the setup routine.
In the running PD environment the externals work without any problems. Only the loading issue remains.
I used dev c++ with mingw to compile it. I'm not familiar with compiling using a makefile. Any help is appreciated.