diff --git a/Makefile b/Makefile
index 907e8c6..33686aa 100644
--- a/Makefile
+++ b/Makefile
@@ -42,9 +42,11 @@ CTUNING = -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
 #CEXTRA = -Wa,-adhlns=$(<:.c=.lst)
 CFLAGS = $(CDEBUG) $(CDEFS) $(CINCS) -O$(OPT) $(CWARN) $(CSTANDARD) $(CEXTRA)
 
-
 #ASFLAGS = -Wa,-adhlns=$(<:.S=.lst),-gstabs
 
+ifeq ($(BUILD),debug)
+	CFLAGS += -DDEBUG
+endif
 
 #Additional libraries.
 
@@ -140,6 +142,8 @@ program: $(BUILD_DIR)/$(TARGET).hex $(BUILD_DIR)/$(TARGET).eep
 	$(AVRDUDE) $(AVRDUDE_FLAGS) $(AVRDUDE_WRITE_FLASH) $(AVRDUDE_WRITE_EEPROM)
 
 
+debug:
+	make "BUILD=debug"
 
 
 # Convert ELF to COFF for use in debugging / simulating in AVR Studio or VMLAB.
diff --git a/include/debug.h b/include/debug.h
new file mode 100644
index 0000000..aa7197a
--- /dev/null
+++ b/include/debug.h
@@ -0,0 +1,16 @@
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include <avr/io.h>
+#include "/usr/include/simavr/avr/avr_mcu_section.h"
+AVR_MCU(F_CPU, "atmega328p");
+const struct avr_mmcu_vcd_trace_t _mytrace[]  _MMCU_ = {
+    { AVR_MCU_VCD_SYMBOL("DDRB"), .what = (void *) &DDRB, },
+    { AVR_MCU_VCD_SYMBOL("DDRD"), .what = (void *) &DDRD, },
+    { AVR_MCU_VCD_SYMBOL("PORTD"), .what = (void *) &PORTD, },
+    { AVR_MCU_VCD_SYMBOL("TCCR0B"), .what = (void *) &TCCR0B, },
+    { AVR_MCU_VCD_SYMBOL("TCCR0A"), .what = (void *) &TCCR0A, },
+    { AVR_MCU_VCD_SYMBOL("OCR0A"), .what = (void*)&OCR0A, },
+};
+
+#endif /* DEBUG_H */
diff --git a/src/main.c b/src/main.c
index f6eec79..f9466e7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,6 +5,10 @@
 #include "main.h"
 #include "io.h"
 
+#ifdef DEBUG
+#include "debug.h"
+#endif /* DEBUG */
+
 void initIO()
 {
     DDRD |= (1 << LED_1);