Buzzer code.

.gitignore

@@ -1,2 +1,3 @@
 openwrt
 sdk
+*swp

software/keypad/Makefile

@@ -1,5 +1,5 @@
 PRG            = uart_hello
-OBJ            = main.o
+OBJ            = main.o buzzer.o
 PROGRAMMER     = buspirate
 PORT           = /dev/ttyACM0
 MCU_TARGET     = atmega8

software/keypad/buzzer.c

@@ -0,0 +1,38 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#include "io.h"
+
+IMPORT_IO(BUZZER);
+
+void buzzer_init(void)
+{
+    // Set up Timer1 - CTC and /256 prescaler
+    TCCR1A = 0;
+    TCCR1B = _BV(WGM12) | _BV(CS12);
+    TCNT1 = 0;
+    OCR1A = 4;
+    OCR1B = 0xFFFF;
+}
+
+void buzzer_start(uint16_t ticks)
+{
+    cli();
+    TIMSK &= ~_BV(OCIE1A);
+    OCR1A = ticks;
+    TIMSK = _BV(OCIE1A);
+    TCNT1 = 0;
+    sei();
+}
+
+void buzzer_stop(void)
+{
+    cli();
+    TIMSK &= ~_BV(OCIE1A);
+    sei();
+}
+
+ISR(TIMER1_COMPA_vect)
+{
+    IO_TOGGLE(BUZZER);
+}

software/keypad/buzzer.h

@@ -0,0 +1,10 @@
+#ifndef __BUZZER_H__
+#define __BUZZER_H__
+
+void buzzer_init(void);
+
+#define TONE_LOW 8
+#define TONE_MID 4
+#define TONE_HIGH 2
+
+#endif

software/keypad/io.h

@@ -0,0 +1,26 @@
+#ifndef _Q__IO_H__
+#define _Q__IO_H__
+
+typedef struct
+{
+    volatile uint8_t *DDR;
+    volatile uint8_t *PORT;
+    volatile uint8_t *PIN;
+    uint8_t Bitmap;
+} TIOPort;
+
+#define DECLARE_IO(name, port, bit) TIOPort g_IO_##name = { &DDR##port, &PORT##port, &PIN##port, (1 << bit) }
+#define IMPORT_IO(name) extern TIOPort g_IO_##name
+#define IO_SET_OUTPUT(name) do { *g_IO_##name.DDR |= g_IO_##name.Bitmap; } while(0)
+#define IO_SET_INPUT(name) do { *g_IO_##name.DDR &= ~g_IO_##name.Bitmap; } while(0)
+#define IO_INPUT_PULLUP(name) do { *g_IO_##name.PORT |= g_IO_##name.Bitmap; } while(0)
+
+#define IO_OUT(name, value) do { if (value) \
+        *g_IO_##name.PORT |= g_IO_##name.Bitmap; \
+    else \
+        *g_IO_##name.PORT &= ~g_IO_##name.Bitmap; } while(0)
+#define IO_TOGGLE(name) do { *g_IO_##name.PORT ^= g_IO_##name.Bitmap; } while(0)
+#define IO_IN(name) (*g_IO_##name.PIN & g_IO_##name.Bitmap)
+
+
+#endif

software/keypad/main.c

@@ -1,31 +1,15 @@
 #include <avr/io.h>
 #include <avr/wdt.h>
+#include <util/delay.h>
 #include <avr/interrupt.h>
 
+#include "io.h"
+#include "buzzer.h"
+
 /////////////////////
 // I/O ports setup //
 /////////////////////
 
-typedef struct
-{
-    volatile uint8_t *DDR;
-    volatile uint8_t *PORT;
-    volatile uint8_t *PIN;
-    uint8_t Bitmap;
-} TIOPort;
-
-#define DECLARE_IO(name, port, bit) TIOPort g_IO_##name = { &DDR##port, &PORT##port, &PIN##port, (1 << bit) }
-#define IO_SET_OUTPUT(name) do { *g_IO_##name.DDR |= g_IO_##name.Bitmap; } while(0)
-#define IO_SET_INPUT(name) do { *g_IO_##name.DDR &= ~g_IO_##name.Bitmap; } while(0)
-#define IO_INPUT_PULLUP(name) do { *g_IO_##name.PORT |= g_IO_##name.Bitmap; } while(0)
-
-#define IO_OUT(name, value) do { if (value) \
-        *g_IO_##name.PORT |= g_IO_##name.Bitmap; \
-    else \
-        *g_IO_##name.PORT &= ~g_IO_##name.Bitmap; } while(0)
-#define IO_TOGGLE(name) do { *g_IO_##name.PORT ^= g_IO_##name.Bitmap; } while(0)
-#define IO_IN(name) (*g_IO_##name.PIN & g_IO_##name.Bitmap)
-
 // Buzzer on PC2
 DECLARE_IO(BUZZER, C, 2);
 // Red LED pn PC1
@@ -54,6 +38,17 @@ int main (void)
     IO_OUT(LED_GREEN, 1);
     IO_OUT(LED_RED, 1);
 
+    buzzer_init();
+    sei();
+
+    buzzer_start(TONE_LOW);
+    _delay_ms(10);
+    buzzer_start(TONE_MID);
+    _delay_ms(10);
+    buzzer_start(TONE_HIGH);
+    _delay_ms(10);
+    buzzer_stop();
+
     for (;;) {}
     return 0;
 }