Hi, This is with regards to ADuC7026. I tried to include a header file in my main program. The header file was created by me and consists of a couple of structures, functions and variable definitions. Besides this, I have a main program file and another file with functions - all in the same folder. The header file is included in the main program file. To prevent duplication of the header file in the function file, I inserted 2 lines of code in my function file: #ifndef FIFO_H_ #define FIFO_H_ However, the compiler is not able to recognize the variables and functions in the header file.