diff --git a/.gitignore b/.gitignore
index 8d2b1ff..cd9493a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,3 +39,7 @@
 *.list
 *.eeprom
 *.pre
+
+# QtCreator user-specific
+*.pro.user
+
diff --git a/avr-c-bp.pro b/avr-c-bp.pro
new file mode 100644
index 0000000..750f61b
--- /dev/null
+++ b/avr-c-bp.pro
@@ -0,0 +1,44 @@
+TEMPLATE = app
+CONFIG += console
+CONFIG -= app_bundle
+CONFIG -= qt
+
+INCLUDEPATH += \
+	lib \
+	/usr/avr/include
+
+DEFINES += __AVR_ATmega328P__ F_CPU=16000000UL
+
+DISTFILES += \
+	style.astylerc \
+	Makefile
+
+HEADERS += \
+	lib/calc.h \
+	lib/iopins.h \
+	lib/usart.h
+
+SOURCES += \
+	lib/iopins.c \
+	main.c
+
+# === Flags for the Clang code model===
+#
+#-Weverything
+#-Wno-c++98-compat
+#-Wno-c++98-compat-pedantic
+#-Wno-unused-macros
+#-Wno-newline-eof
+#-Wno-exit-time-destructors
+#-Wno-global-constructors
+#-Wno-gnu-zero-variadic-macro-arguments
+#-Wno-documentation
+#-Wno-missing-prototypes
+#-std=gnu99
+#-Wno-gnu
+#-Wno-format-nonliteral
+#-Wno-conversion
+#-Wno-pointer-sign
+#-Wno-unknown-attributes
+#-Wno-main-return-type
+#-Wno-missing-noreturn
diff --git a/lib/usart.c b/lib/usart.c
index 189c66b..ace6eaa 100644
--- a/lib/usart.c
+++ b/lib/usart.c
@@ -24,6 +24,26 @@ void usart_init(uint16_t ubrr)
 }
 
 
+/** Send byte over USART */
+void usart_tx(uint8_t data)
+{
+	// Wait for transmit buffer
+	while (!usart_tx_ready());
+	// send it
+	UDR0 = data;
+}
+
+
+/** Receive one byte over USART */
+uint8_t usart_rx(void)
+{
+	// Wait for data to be received
+	while (!usart_rx_ready());
+	// Get and return received data from buffer
+	return UDR0;
+}
+
+
 /** Send string over USART */
 void usart_puts(const char* str)
 {
diff --git a/lib/usart.h b/lib/usart.h
index 760a4eb..6807588 100644
--- a/lib/usart.h
+++ b/lib/usart.h
@@ -14,6 +14,8 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#include "calc.h"
+
 
 /* USART BAUD RATE REGISTER values at 16 MHz */
 enum {
@@ -40,55 +42,36 @@ void usart_init(uint16_t ubrr);
 #define usart_tx_ready() (0 != (UCSR0A & (1 << UDRE0)))
 
 
-
-
 // ---- Enable UART interrupts ------------
 
 /** Enable or disable RX ISR */
-inline void usart_rx_isr_enable(bool yes)
-{
-	set_bit(UCSR0B, RXCIE0, yes);
-}
+#define usart_rx_isr_enable(yes) set_bit(UCSR0B, RXCIE0, (yes))
+
 
 /** Enable or disable TX ISR (1 byte is sent) */
-inline void usart_tx_isr_enable(bool yes)
-{
-	set_bit(UCSR0B, TXCIE0, yes);
-}
+#define usart_tx_isr_enable(yes) set_bit(UCSR0B, TXCIE0, (yes))
+
 
 /** Enable or disable DRE ISR (all is sent) */
-inline void usart_dre_isr_enable(bool yes)
-{
-	set_bit(UCSR0B, UDRIE0, yes);
-}
+#define usart_dre_isr_enable(yes) set_bit(UCSR0B, UDRIE0, (yes))
 
 
 // ---- Basic IO --------------------------
 
 /** Send byte over USART */
-inline void usart_tx(uint8_t data)
-{
-	// Wait for transmit buffer
-	while (!usart_tx_ready());
-	// send it
-	UDR0 = data;
-}
+void usart_tx(uint8_t data);
 
 
 /** Receive one byte over USART */
-inline uint8_t usart_rx(void)
-{
-	// Wait for data to be received
-	while (!usart_rx_ready());
-	// Get and return received data from buffer
-	return UDR0;
-}
+uint8_t usart_rx(void);
+
 
 /** Send byte over UART */
 #define usart_putc(data) usart_tx((data))
 
+
 /** Clear receive buffer */
-void usart_clear_rx();
+void usart_clear_rx(void);
 
 
 // ---- Strings ---------------------------
@@ -96,5 +79,6 @@ void usart_clear_rx();
 /** Send string over UART */
 void usart_puts(const char* str);
 
+
 /** Send progmem string over UART */
 void usart_puts_P(const char* str);