diff --git a/avr/makefile b/avr/makefile
index 74e8ac9..de9ce4f 100644
--- a/avr/makefile
+++ b/avr/makefile
@@ -4,10 +4,12 @@ SOURCES = src/avrtest.c
 CC = avr-gcc
 OBJCOPY = avr-objcopy
 MMCU = atmega88
+F_CPU = 10000000UL
+#F_CPU = 11059200UL
 
 DUMMY_BINARY:=$(shell mkdir -p binary)
 
-CFLAGS = -mmcu=$(MMCU) -Wall -Os -std=gnu99
+CFLAGS = -mmcu=$(MMCU) -DF_CPU=$(F_CPU) -Wall -Os -std=gnu99
 
 compile : binary/$(PROJECT).out
 
@@ -18,7 +20,7 @@ binary/$(PROJECT).out: $(SOURCES)
 	$(CC) $(CFLAGS) -I./ -o binary/$(PROJECT).out $(SOURCES)
 
 program: binary/$(PROJECT).hex
-	avrdude -p m88 -c buspirate -P /dev/cu.PL2303-003012FA -e -U flash:w:binary/$(PROJECT).hex
+	avrdude -p m88 -c buspirate -P /dev/cu.PL2303-00* -e -U flash:w:binary/$(PROJECT).hex
 
 clean:
 	rm -rf binary/
diff --git a/avr/src/avrtest.c b/avr/src/avrtest.c
index 157a5d4..8fc764a 100644
--- a/avr/src/avrtest.c
+++ b/avr/src/avrtest.c
@@ -3,13 +3,13 @@
 #include <stdint.h>
 
 #ifndef F_CPU
-  #warning "F_CPU wasn't set in makefile, so we do it now with 8.0 MHz"
-  #define F_CPU 1000000UL
+  #warning "F_CPU wasn't set in makefile, so we do it now with 10.0 MHz"
+  #define F_CPU 10000000UL
 #endif
 
 
 // setting baud rate
-#define BAUD 4800UL
+#define BAUD 9600UL
 
 // uart baud rate checks
 #define UBRR_VAL ((F_CPU+BAUD*8)/(BAUD*16)-1)
@@ -17,7 +17,7 @@
 #define BAUD_ERROR ((BAUD_REAL*1000)/BAUD)
 
 #if ((BAUD_ERROR<990) || (BAUD_ERROR>1010))
-  #error baudrate error higher than 1%! 
+  #warning baudrate error higher than 1%! 
 #endif