Basically it waits for a interrupt (push button) and checks if an eeprom 24c64 has FF in all its address then turns a led if true, this is only if the switch in port D is closed, if not, it writes a byte number "i" in the adress number "i" and then verify if the data written is correct then turns a led on if true.-Basically it waits for a interrupt (push button) and checks if an eeprom 24c64 has FF in all its address then turns a led if true, this is only if the switch in port D is closed, if not,　it writes a byte number "i" in the adress number "i" and then verify if the data written is correct then turns a led　on if true.