Dear all, I am testing the USB HID generic AtUsbHid.dll from Atmel in order to build a small pc application that can communicate with an ATusb162 through USB canal. Actually I can compile successfully when the functions from AtUsbHid.dll are used in the main.c file. File main.c that compile fine: [code] /*file main.c */ #include <stdio.h> #include <windows.h> #include "AtUsbHid.h" int main(int arg, char* argv[]) { HINSTANCE hLib = NULL; hLib = LoadLibrary(AT_USB_HID_DLL); if(loadFuncPointers(hLib)) printf ("loaded"); FreeLibrary(hLib); return 0; } [/code] The command used was: [code] g++ -Wall main.c AtUsbHid.dll -o main [/code] --->>> Until this point it works just fine. :) Problems arrive when I try to use the functions in another file. Please have a look at the following: The main.c file: [code] /*file main.c*/ #include "bidon.h" int main(int arg, char* argv[]) { test(); return 0; } [/code] The bidon.h file: [code] /*file bidon.h*/ #ifndef _BIDON_H_ #define _BIDON_H_ #include <stdio.h> #include <windows.h> #include "AtUsbHid.h" #define VID 0x03EB #define PID 0x2013 extern void test(void); #endif /*_BIDON_H_*/ [/code] And the bidon.c file: [code] /*file: bidon.c*/ #include "bidon.h" void test(void) { HINSTANCE hLib = NULL; hLib = LoadLibrary(AT_USB_HID_DLL); if(loadFuncPointers(hLib)) printf("\r\nloaded"); if(DYNCALL(findHidDevice(VID, PID))) printf("\r\nopened"); DYNCALL(writeData)((UCHAR *)"11"); Sleep(100); DYNCALL(writeData)((UCHAR *)"01"); afficher(); DYNCALL(closeDevice()); FreeLibrary(hLib); printf("\r\nclosed\r\n"); } [/code] When compiling with: [code] g++ -Wall main.c bidon.c AtUsbHid.dll -o main [/code] I got the following error: [code] AtUsbHid.h:107: warning: 'bool loadFuncPointers(HINSTANCE__*)' defined but not used C:/DOCUME~1/SBIGLE~1.LHT/LOCALS~1/Temp/ccZYEZ1v.o:bidon.c:(.bss+0x0): multiple definition of `_lpfindHidDevice' C:/DOCUME~1/SBIGLE~1.LHT/LOCALS~1/Temp/ccGROaaE.o:main.c:(.bss+0x0): first defined here C ..... ... .. . [/code] I would appreciate any comment or advice. Thank you for helping. Stephane -- View this message in context: http://www.nabble.com/how-to-include-some-dll-functions-in-a-project-tp20625105p20625105.html Sent from the gcc - Help mailing list archive at Nabble.com.