diff --git a/Makefile b/Makefile
index 744cd7a..85a736e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-ARCH = ti
+ARCH = avr
 
 include Makefile.$(ARCH)
 
diff --git a/Makefile.avr b/Makefile.avr
index e5a39d2..bcb8009 100644
--- a/Makefile.avr
+++ b/Makefile.avr
@@ -1,11 +1,15 @@
 PROG = main
 
+MCU = atmega328p
+
 CC = avr-gcc
-CFLAGS += -mmcu=atmega328p
+CFLAGS += -mmcu=$(MCU)
 CFLAGS += -DF_CPU=16000000UL
 CFLAGS += -Os
 CFLAGS += -w
 
+LDFLAGS += -mmcu=$(MCU)
+
 AVDFLAGS += -p m328p
 AVDFLAGS += -c arduino
 AVDFLAGS += -b 115200
@@ -23,8 +27,11 @@ $(PROG).hex: $(PROG)
 
 main: main.o avr.o
 
+#main.o: avr.h
+#avr.o: avr.h
+
 clean:
-	rm -f $(PROG) *.hex .upload
+	rm -f $(PROG) *.o *.hex .upload
 
 
 
diff --git a/avr.h b/avr.h
index a248e20..66fd12d 100644
--- a/avr.h
+++ b/avr.h
@@ -9,6 +9,8 @@
 #define JIFFIES_PER_SECOND 50
 #define JIFFY_uS (1000000 / JIFFIES_PER_SECOND)
 
+#define bit(pin, bit, on) pin = (on ? (pin | bit) : (pin & ~bit))
+
 #define mode(on) bit(PORTD, _BV(0), on)
 #define sin(on) bit(PORTD, _BV(1), on)
 #define sclk(on) bit(PORTD, _BV(2), on)
diff --git a/main.c b/main.c
index 9d08e54..0d774ca 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdbool.h>
-#include "ti.h"
+
+#include <avr/io.h>
+#include <util/delay.h>
+
+#if defined (__AVR_ATmega328P__)
+#  include "avr.h"
+#else
+#  include "ti.h"
+#endif
 
 // Number of shift registers in your scoreboard
 // If you want scores to go over 199, you need 8
@@ -40,9 +48,6 @@ enum {
 #define BTN_LEFT _BV(1)
 #define BTN_RIGHT _BV(0)
 
-
-#define bit(pin, bit, on) pin = (on ? (pin | bit) : (pin & ~bit))
-
 const uint8_t seven_segment_digits[] = {
 	0x7b, 0x60, 0x37, 0x76, 0x6c, 0x5e, 0x5f, 0x70, 0x7f, 0x7e
 };
diff --git a/ti.h b/ti.h
index 8323788..c6bf051 100644
--- a/ti.h
+++ b/ti.h
@@ -8,6 +8,8 @@
 
 #define JIFFIES_PER_SECOND 60
 
+#define bit(pin, bit, on) pin = (on ? (pin | bit) : (pin & ~bit))
+
 #define mode(on) bit(P1OUT, _BV(0), on)
 #define sin(on) bit(P1OUT, _BV(1), on)
 #define sclk(on) bit(P1OUT, _BV(2), on)