Dear Sir
I add a modbus.c file to Example/User on project. In main.c i #include "modbus.c", but an fatal error "modbus.c" file not found happened.
could you please teach me how can i solve it.
Thanks you very much.
Maybe you could tell us what book recommends "include" of a *.c file?
Good books would describe the difference between *.c and *.h (i.e. header files).
Next thing - the compiler requires the existence of the files. And the compiler manual describes where the compiler will look for files.
Try using "add existing file to project" to add the file into the compilation.
Using #include .C files is not without precedence, but if it can't find the file you should review the Include Path settings to confirm the directory the file is in gets searched.