-OPTIMIZE = -Os
-PROGRAMMER = stk500v2 # avr911
-DEFS = -D$(call uc, $(MCU_TARGET))
-FLASHCMD = avrdude -p $(MCU_TARGET) -P /dev/ttyUSB0 -c $(PROGRAMMER) -U flash:w:# no space at the end
+F_CPU = 20000000
+OPTIMIZE = -Os # -Os
+DEBUG = -gdwarf-2
+WARNING = -pedantic -Wall -Wstrict-prototypes
+PROGRAMMER = avr911
+PROG_PORT = /dev/ttyUSB0
+DEFS = -D$(call uc, $(MCU_TARGET)) -DF_CPU=$(F_CPU)
+FLASHCMD = avrdude -p $(MCU_TARGET) -P $(PROG_PORT) -c $(PROGRAMMER) -U flash:w:# no space at the end