organized tests

avr_tests/Makefile

@@ -0,0 +1,7 @@
+tests= usart_test.elf io_test.elf
+
+all: $(tests)
+
+%.elf:%.c
+	avr-gcc $< -mmcu=atmega168 -O -o $@
+	avrdude -p m168 -c avrispmkii  -U flash:w:$@:a

avr_tests/io_test.c

@@ -0,0 +1,19 @@
+#include <avr/io.h>
+#define F_CPU 18000000UL
+#include <util/delay.h>
+
+int main(void)
+{
+//	CLKPR |= _BV(CLKPCE);
+//	CLKPR &= ~(_BV(CLKPS0)
+//			| _BV(CLKPS1)
+//			| _BV(CLKPS2)
+//			| _BV(CLKPS3));
+	DDRC |= _BV(PC5);
+	while(1)
+	{
+		PORTC ^= _BV(PC5);
+		_delay_ms(4000);
+	}
+	return 0;
+}

avr_tests/usart_test.c

@@ -0,0 +1,71 @@
+#include <avr/io.h>
+#include <stdlib.h>
+#include <avr/interrupt.h>
+
+//#define USART_U2X_EN
+
+#define F_CPU 20000000UL
+#include <util/delay.h>
+#define USART_BAUD 2400
+#define UBRR_VALUE_DS 520
+
+#ifndef USART_U2X_EN
+#define UBRR_VALUE (F_CPU/16/USART_BAUD-1)
+#else
+#define UBRR_VALUE (F_CPU/8/USART_BAUD-1)
+#endif
+
+#if !(UBRR_VALUE == UBRR_VALUE_DS)
+#warning "Calculated UBRR value differs from the value given in the datasheet: " 
+#define UBRR_VALUE UBRR_VALUE_DS
+#endif
+
+int cnt;
+
+void
+usart_init(void)
+{
+	UBRR0H = (unsigned char)(UBRR_VALUE >> 8);
+	UBRR0L = (unsigned char)UBRR_VALUE;
+#ifdef USART_U2X_EN
+	UCSR0A |= _BV(U2X0);
+#endif
+	UCSR0B = _BV(TXEN0) | _BV(TXCIE0);
+	UCSR0C = _BV(UCSZ00) | _BV(UCSZ01);
+	//UCSR0C = _BV(UCSZ00) | _BV(UCSZ01);
+	cnt = 0;
+	sei();
+}
+
+
+ISR(USART_TX_vect)
+{
+	if(!cnt)
+	{
+		UDR0 = '\n';
+		cnt++;
+	}
+	else
+	{
+		cnt = (cnt + 1) % 10;
+		UDR0 = '0' + cnt;
+	}
+}
+
+int main(void)
+{
+	DDRC |= _BV(PC5);
+	usart_init();
+	while(!(UCSR0A & _BV(UDRE0)));
+	UDR0 = '0';
+	while(1)
+	{
+		PORTC ^= _BV(PC5);
+		_delay_ms(500);
+		PORTC ^= _BV(PC5);
+		_delay_ms(1000);
+		PORTC ^= _BV(PC5);
+		_delay_ms(500);
+	}
+	return 0;
+}