speaker: Initial implementation

4 files changed, 65 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index addea24..8996720 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ MCU = atmega88
 
 all: sanduhr.hex
 
-sanduhr.elf: main.c i2c.c i2c.h uart.c uart.h timer.c timer.h gyro.c gyro.h accel.c accel.h common.h
+sanduhr.elf: main.c i2c.c i2c.h uart.c uart.h timer.c timer.h gyro.c gyro.h accel.c accel.h common.h speaker.c speaker.h
 	avr-gcc -std=gnu99 -mmcu=$(MCU) -Os -o $@ $^
 
 sanduhr.hex: sanduhr.elf
diff --git a/main.c b/main.c
index a581ea8..608327c 100644
--- a/main.c
+++ b/main.c
@@ -13,6 +13,7 @@
 #include "timer.h"
 #include "gyro.h"
 #include "accel.h"
+#include "speaker.h"
 
 static void ledInit () {
 	/* set led1,led2 to output */
@@ -49,6 +50,7 @@ int main () {
 	uartInit ();
 	gyroInit ();
 	accelInit ();
+	speakerInit ();
 	set_sleep_mode (SLEEP_MODE_IDLE);
 
 	printf ("initialization done\n");
@@ -58,6 +60,10 @@ int main () {
 	gyroStart ();
 	accelStart ();
 
+	speakerStart ();
+	_delay_ms (200);
+	speakerStop ();
+
 	timerStart ();
 	bool checkGyro = false;
 	while (1) {
diff --git a/speaker.c b/speaker.c
new file mode 100644
index 0000000..d903c57
--- /dev/null
+++ b/speaker.c
@@ -0,0 +1,49 @@
+/*	speaker control, uses timer2
+ */
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <stdbool.h>
+
+#include "speaker.h"
+
+static bool value = false;
+
+static void speakerSet () {
+	if (value) {
+		PORTD = PORTD | (1 << PD6);
+	} else {
+		PORTD = PORTD & ~(1 << PD6);
+	}
+}
+
+ISR(TIMER2_OVF_vect) {
+	value = !value;
+	speakerSet ();
+}
+
+void speakerInit () {
+	/* set PD6 to output */
+	DDRD |= (1 << PD6);
+	/* value is false */
+	speakerSet ();
+}
+
+void speakerStart () {
+	/* reset timer value */
+	TCNT2 = 0;
+	/* set normal mode timer0 */
+	TCCR2A = 0;
+	/* enable overflow interrupt */
+	TIMSK2 = (1 << TOIE2);
+	/* io clock with 1024 prescaler */
+	TCCR2B = (TCCR2B & ~((1 << CS21)) | (1 << CS22) | (1 << CS20));
+}
+
+void speakerStop () {
+	/* zero clock source */
+	TCCR2B = 0;
+	value = false;
+	speakerSet ();
+}
+
diff --git a/speaker.h b/speaker.h
new file mode 100644
index 0000000..dec1d20
--- /dev/null
+++ b/speaker.h
@@ -0,0 +1,9 @@
+#ifndef SPEAKER_H
+#define SPEAKER_H
+
+void speakerInit ();
+void speakerStart ();
+void speakerStop ();
+
+#endif /* SPEAKER_H */
+