keychron_qmk_firmware/quantum/audio.c
2016-04-05 09:21:44 -04:00

365 lines
9.6 KiB
C

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include "audio.h"
#include "keymap_common.h"
#define PI 3.14159265
// #define PWM_AUDIO
#ifdef PWM_AUDIO
#include "wave.h"
#define SAMPLE_DIVIDER 39
#define SAMPLE_RATE (2000000.0/SAMPLE_DIVIDER/2048)
// Resistor value of 1/ (2 * PI * 10nF * (2000000 hertz / SAMPLE_DIVIDER / 10)) for 10nF cap
#endif
void delay_us(int count) {
while(count--) {
_delay_us(1);
}
}
int voices = 0;
int voice_place = 0;
double frequency = 0;
int volume = 0;
long position = 0;
double frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
bool sliding = false;
int max = 0xFF;
float sum = 0;
int value = 128;
float place = 0;
float places[8] = {0, 0, 0, 0, 0, 0, 0, 0};
uint16_t place_int = 0;
bool repeat = true;
uint8_t * sample;
uint16_t sample_length = 0;
bool notes = false;
bool note = false;
float note_frequency = 0;
float note_length = 0;
uint16_t note_position = 0;
float (* notes_pointer)[][2];
uint8_t notes_length;
bool notes_repeat;
uint8_t current_note = 0;
void stop_all_notes() {
voices = 0;
#ifdef PWM_AUDIO
TIMSK3 &= ~_BV(OCIE3A);
#else
TIMSK3 &= ~_BV(OCIE3A);
TCCR3A &= ~_BV(COM3A1);
#endif
notes = false;
note = false;
frequency = 0;
volume = 0;
for (int i = 0; i < 8; i++) {
frequencies[i] = 0;
volumes[i] = 0;
}
}
void stop_note(double freq) {
#ifdef PWM_AUDIO
freq = freq / SAMPLE_RATE;
#endif
for (int i = 7; i >= 0; i--) {
if (frequencies[i] == freq) {
frequencies[i] = 0;
volumes[i] = 0;
for (int j = i; (j < 7); j++) {
frequencies[j] = frequencies[j+1];
frequencies[j+1] = 0;
volumes[j] = volumes[j+1];
volumes[j+1] = 0;
}
}
}
voices--;
if (voices < 0)
voices = 0;
if (voices == 0) {
#ifdef PWM_AUDIO
TIMSK3 &= ~_BV(OCIE3A);
#else
TIMSK3 &= ~_BV(OCIE3A);
TCCR3A &= ~_BV(COM3A1);
#endif
frequency = 0;
volume = 0;
note = false;
} else {
double freq = frequencies[voices - 1];
int vol = volumes[voices - 1];
double starting_f = frequency;
if (frequency < freq) {
sliding = true;
for (double f = starting_f; f <= freq; f += ((freq - starting_f) / 2000.0)) {
frequency = f;
}
sliding = false;
} else if (frequency > freq) {
sliding = true;
for (double f = starting_f; f >= freq; f -= ((starting_f - freq) / 2000.0)) {
frequency = f;
}
sliding = false;
}
frequency = freq;
volume = vol;
}
}
void init_notes() {
#ifdef PWM_AUDIO
PLLFRQ = _BV(PDIV2);
PLLCSR = _BV(PLLE);
while(!(PLLCSR & _BV(PLOCK)));
PLLFRQ |= _BV(PLLTM0); /* PCK 48MHz */
/* Init a fast PWM on Timer4 */
TCCR4A = _BV(COM4A0) | _BV(PWM4A); /* Clear OC4A on Compare Match */
TCCR4B = _BV(CS40); /* No prescaling => f = PCK/256 = 187500Hz */
OCR4A = 0;
/* Enable the OC4A output */
DDRC |= _BV(PORTC6);
TIMSK3 &= ~_BV(OCIE3A); // Turn off 3A interputs
TCCR3A = 0x0; // Options not needed
TCCR3B = _BV(CS31) | _BV(CS30) | _BV(WGM32); // 64th prescaling and CTC
OCR3A = SAMPLE_DIVIDER - 1; // Correct count/compare, related to sample playback
#else
DDRC |= _BV(PORTC6);
TIMSK3 &= ~_BV(OCIE3A); // Turn off 3A interputs
TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
TCCR3B = (1 << WGM33) | (1 << WGM32) | (0 << CS32) | (1 << CS31) | (0 << CS30);
#endif
}
ISR(TIMER3_COMPA_vect) {
if (note) {
#ifdef PWM_AUDIO
if (voices == 1) {
// SINE
OCR4A = pgm_read_byte(&sinewave[(uint16_t)place]) >> 2;
// SQUARE
// if (((int)place) >= 1024){
// OCR4A = 0xFF >> 2;
// } else {
// OCR4A = 0x00;
// }
// SAWTOOTH
// OCR4A = (int)place / 4;
// TRIANGLE
// if (((int)place) >= 1024) {
// OCR4A = (int)place / 2;
// } else {
// OCR4A = 2048 - (int)place / 2;
// }
place += frequency;
if (place >= SINE_LENGTH)
place -= SINE_LENGTH;
} else {
int sum = 0;
for (int i = 0; i < voices; i++) {
// SINE
sum += pgm_read_byte(&sinewave[(uint16_t)places[i]]) >> 2;
// SQUARE
// if (((int)places[i]) >= 1024){
// sum += 0xFF >> 2;
// } else {
// sum += 0x00;
// }
places[i] += frequencies[i];
if (places[i] >= SINE_LENGTH)
places[i] -= SINE_LENGTH;
}
OCR4A = sum;
}
#else
if (frequency > 0) {
// ICR3 = (int)(((double)F_CPU) / frequency); // Set max to the period
// OCR3A = (int)(((double)F_CPU) / frequency) >> 1; // Set compare to half the period
if (place > 10) {
voice_place = (voice_place + 1) % voices;
place = 0.0;
}
ICR3 = (int)(((double)F_CPU) / frequencies[voice_place]); // Set max to the period
OCR3A = (int)(((double)F_CPU) / frequencies[voice_place]) >> 1; // Set compare to half the period
place++;
}
#endif
}
// SAMPLE
// OCR4A = pgm_read_byte(&sample[(uint16_t)place_int]);
// place_int++;
// if (place_int >= sample_length)
// if (repeat)
// place_int -= sample_length;
// else
// TIMSK3 &= ~_BV(OCIE3A);
if (notes) {
#ifdef PWM_AUDIO
OCR4A = pgm_read_byte(&sinewave[(uint16_t)place]) >> 0;
place += note_frequency;
if (place >= SINE_LENGTH)
place -= SINE_LENGTH;
#else
if (note_frequency > 0) {
ICR3 = (int)(((double)F_CPU) / note_frequency); // Set max to the period
OCR3A = (int)(((double)F_CPU) / note_frequency) >> 1; // Set compare to half the period
} else {
ICR3 = 0;
OCR3A = 0;
}
#endif
note_position++;
if (note_position >= note_length) {
current_note++;
if (current_note >= notes_length) {
if (notes_repeat) {
current_note = 0;
} else {
#ifdef PWM_AUDIO
TIMSK3 &= ~_BV(OCIE3A);
#else
TIMSK3 &= ~_BV(OCIE3A);
TCCR3A &= ~_BV(COM3A1);
#endif
notes = false;
return;
}
}
#ifdef PWM_AUDIO
note_frequency = (*notes_pointer)[current_note][0] / SAMPLE_RATE;
note_length = (*notes_pointer)[current_note][1];
#else
note_frequency = (*notes_pointer)[current_note][0];
note_length = (*notes_pointer)[current_note][1] / 4;
#endif
note_position = 0;
}
}
}
void play_notes(float (*np)[][2], uint8_t n_length, bool n_repeat) {
if (note)
stop_all_notes();
notes = true;
notes_pointer = np;
notes_length = n_length;
notes_repeat = n_repeat;
place = 0;
current_note = 0;
#ifdef PWM_AUDIO
note_frequency = (*notes_pointer)[current_note][0] / SAMPLE_RATE;
note_length = (*notes_pointer)[current_note][1];
#else
note_frequency = (*notes_pointer)[current_note][0];
note_length = (*notes_pointer)[current_note][1] / 4;
#endif
note_position = 0;
#ifdef PWM_AUDIO
TIMSK3 |= _BV(OCIE3A);
#else
TIMSK3 |= _BV(OCIE3A);
TCCR3A |= _BV(COM3A1);
#endif
}
void play_sample(uint8_t * s, uint16_t l, bool r) {
stop_all_notes();
place_int = 0;
sample = s;
sample_length = l;
repeat = r;
#ifdef PWM_AUDIO
TIMSK3 |= _BV(OCIE3A);
#else
#endif
}
void play_note(double freq, int vol) {
if (notes)
stop_all_notes();
note = true;
#ifdef PWM_AUDIO
freq = freq / SAMPLE_RATE;
#endif
if (freq > 0) {
if (frequency != 0) {
double starting_f = frequency;
if (frequency < freq) {
for (double f = starting_f; f <= freq; f += ((freq - starting_f) / 2000.0)) {
frequency = f;
}
} else if (frequency > freq) {
for (double f = starting_f; f >= freq; f -= ((starting_f - freq) / 2000.0)) {
frequency = f;
}
}
}
frequency = freq;
volume = vol;
frequencies[voices] = frequency;
volumes[voices] = volume;
voices++;
}
#ifdef PWM_AUDIO
TIMSK3 |= _BV(OCIE3A);
#else
TIMSK3 |= _BV(OCIE3A);
TCCR3A |= _BV(COM3A1);
#endif
}