2008/11/23 bigbig <stephane.bigler@xxxxxxx>: > > I solved the problem by moving all the include directives from bidon.h to > bidon.c. > > :-) > > If anyone could explain why... > > thank you. > Stephane It seems to me that one of the files "windows.h", "AtUsbHid.h" contain not only definitions but also implementations. Thats why being included both into main.c and bidon.c it caused multiple function definitions. Try to check this out. Alexey Salmin