#include <avr/io.h>
#include <avr/interrupt.h>
#include <inttypes.h>
Like this You have to include basic header files... If you check in external dependency [Left hand side of AVR studio {AVR GCC}] there avrlibdefs.h, common.h, eeprom.h, fuse.h, interrupt.h, inttypes.h, io.h, iom32.h, lock.h, portpins.h, sfr_defs.h, stddef.h, stdint.h, version.h, wdt.h.... Like these you can see lot dependent library files... Not exact these file... For example i have included all the files.... If these files included means you will not get errors above what you said..