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129 lines
2.9 KiB
C

#include <stdint.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <util/delay.h>
#include <util/atomic.h>
#include "music.h"
/* Sine lookup table for the PWM generator (pp = 32) */
static const PROGMEM unsigned char sine_lookup[]={
0x10,0x13,0x16,0x19,0x1b,0x1d,0x1f,0x20,
0x20,0x20,0x1f,0x1d,0x1b,0x19,0x16,0x13,
0x10,0x0d,0x0a,0x07,0x05,0x03,0x01,0x00,
0x00,0x00,0x01,0x03,0x05,0x07,0x0a,0x0d
};
const MUSIC_Note MUSIC_Tetris[] = {
{ MUSIC_E5, MUSIC_4 },
{ MUSIC_B4, MUSIC_8 },
{ MUSIC_C5, MUSIC_8 },
{ MUSIC_D5, MUSIC_4 },
{ MUSIC_C5, MUSIC_8 },
{ MUSIC_D5, MUSIC_8 },
{ MUSIC_A4, MUSIC_4 },
{ MUSIC_A4, MUSIC_8 },
{ MUSIC_C5, MUSIC_8 },
{ MUSIC_E5, MUSIC_4 },
{ MUSIC_D5, MUSIC_8 },
{ MUSIC_C5, MUSIC_8 },
{ MUSIC_B4, MUSIC_4 + MUSIC_8 },
{ MUSIC_C5, MUSIC_8 },
{ MUSIC_D5, MUSIC_4 },
{ MUSIC_E5, MUSIC_4 },
{ MUSIC_C5, MUSIC_4 },
{ MUSIC_A4, MUSIC_4 },
{ MUSIC_A4, MUSIC_8 },
MUSIC_END };
static void delay_ms(uint16_t delay);
static void pwm_init (void);
static void pwm_deinit (void);
static void pwm_gen(uint16_t tone, uint16_t periods);
void Music_PlayTrack (MUSIC_Track track)
{
pwm_init();
while (!MUSIC_IS_END(*track)) {
if (track->tone == 0) {
delay_ms(track->duration);
} else {
uint16_t periods = (uint32_t)track->duration * (uint32_t)track->tone / 1000;
pwm_gen(track->tone, periods);
delay_ms(MUSIC_32 / 2);
}
++track;
}
pwm_deinit();
}
static void delay_ms(uint16_t delay)
{
while (delay--)
_delay_ms(1);
}
void pwm_init (void)
{
//setup PWM timer
DDRD |= _BV(PIND5); // speaker pin => output
TCCR1A = _BV(COM1A1) | _BV(COM1A0) | _BV(WGM10); //set on match
TCCR1B = _BV(CS10) | _BV(WGM12); //fast PWM (8 bit), clk/1 source
//setup sample timer (CTC Mode)
#if defined(__AVR_ATmega1284P__)
TCCR3A = 0;
TCCR3B = _BV(CS30) | _BV(WGM32); // clk/1
#elif defined(__AVR_ATmega324PA__)
TCCR0A = _BV(WGM01);
TCCR0B = _BV(CS01); // clk/8
#endif
}
void pwm_deinit (void)
{
TCCR1A = 0;
TCCR1B = 0;
#if defined(__AVR_ATmega1284P__)
TCCR3A = 0;
TCCR3B = 0;
#elif defined(__AVR_ATmega324PA__)
TCCR0A = 0;
TCCR0B = 0;
#endif
}
void pwm_gen(uint16_t tone, uint16_t periods)
{
//calculate single sine sample duration
#if defined(__AVR_ATmega1284P__)
OCR3A = F_CPU / tone / sizeof(sine_lookup) - 1;
#elif defined(__AVR_ATmega324PA__)
OCR0A = F_CPU / 8 / tone / sizeof(sine_lookup) - 1;
#endif
for (uint16_t period=0; period < periods; ++period) {
for (uint8_t spl=0; spl < sizeof(sine_lookup); ++spl) {
//wait for timer ready for next spl
#if defined(__AVR_ATmega1284P__)
loop_until_bit_is_set(TIFR3, OCF1A);
TIFR3 = _BV(OCF1A); //clear OCF
#elif defined(__AVR_ATmega324PA__)
loop_until_bit_is_set(TIFR0, OCF0A);
TIFR0 = _BV(OCF0A); //clear OCF
#endif
OCR1A = pgm_read_byte(sine_lookup + spl) + 0x70;
}
}
}