diff --git a/src/.gitignore b/src/.gitignore
index a06c509..8452226 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -2,3 +2,5 @@ led-controller
 *.o
 *.hex
 *.lst
+*.map
+*.elf
diff --git a/src/Makefile b/src/Makefile
index c7bd9cc..16b8f41 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,7 +1,7 @@
 # required packages
 # sudo aptitude install avrdude gcc-avr avr-libc
 # the program
-PROG=led-controller
+TARGET=led-controller
 # to compile
 CC=avr-gcc
 OBJDUMP=avr-objdump
@@ -18,13 +18,26 @@ PROGRAMMER=usbtiny
 # to flash
 #AVRDUDE=avrdude -p $(DEVICE) -P $(PORT) -c $(PROGRAMMER)
 FLASHER=avrdude -p $(DEVICE) -c $(PROGRAMMER)
+# source files to compile
+SRC = main.c
+# object files.
+OBJ = $(SRC:.c=.o)
+# listing files.
+LST = $(SRC:.c=.lst)
 
-all: prog
+all: program $(TARGET).lst verify burn-fuse flash
 
-prog: verify $(PROG).c
-	$(CC) $(CFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -o $(PROG) $(PROG).c
-	$(OBJDUMP) -h -S $(PROG) > $(PROG).lst
-	$(OBJCOPY) -j .text -j .data -O ihex $(PROG) $(PROG).hex
+verify:
+	$(FLASHER)
+	if [ $$? -eq 0 ]; then \
+		echo "flasher configured correctly"; \
+	else \
+		echo "flasher not configured correctly in Makefile"; \
+		exit 1; \
+	fi
+
+read-fuse:
+	$(FLASHER) -U lfuse:r:lfuse.raw:r -U hfuse:r:hfuse.raw:r -U efuse:r:efuse.raw:r
 
 # Fuse low byte:
 # 0xff = 1 1 1 1   1 1 1 1
@@ -52,28 +65,29 @@ prog: verify $(PROG).c
 burn-fuse:
 	$(FLASHER) -U lfuse:w:0xff:m -U hfuse:w:0xdf:m -U efuse:w:0x04:m
 
-read-fuse:
-	$(FLASHER) -U lfuse:r:lfuse.raw:r -U hfuse:r:hfuse.raw:r -U efuse:r:efuse.raw:r
-
-flash:
-	$(FLASHER) -U flash:w:$(PROG).hex:i
-
 read-flash:
 	$(FLASHER) -U flash:r:flash_dump.hex:i
 
-flash: prog load
-install : prog load
-load:
-	$(FLASHER) -U flash:w:$(PROG).hex:i
+flash:
+	$(FLASHER) -U flash:w:$(TARGET).hex:i
+
+program: $(TARGET).hex
+
+# compile
+%.o: %.c
+	$(CC) $(CFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -c -o $@ $<
+
+# link
+%.elf: $(OBJ)
+	$(CC) $(CFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -Wl,-Map=$(TARGET).map,--cref -o $@ $(OBJ)
+
+# extended listing
+%.lst: %.elf
+	$(OBJDUMP) -h -S $< > $@
+
+# output file
+%.hex: %.elf
+	$(OBJCOPY) -j .text -j .data -O ihex $< $@
 
 clean:
-	rm -f $(PROG) *.hex *.lst
-
-verify:
-	$(FLASHER)
-	if [ $$? -eq 0 ]; then \
-		echo "flasher configured correctly"; \
-	else \
-		echo "flasher not configured correctly in Makefile"; \
-		exit 1; \
-	fi
+	rm -f $(TARGET) $(TARGET).hex $(TARGET).elf $(LST) $(TARGET).lst $(OBJ)