quantum/audio/audio.c

   1 /* Copyright 2016 Jack Humbert
   2  *
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <stdio.h>
  18 #include <string.h>
  19 //#include <math.h>
  20 #include <avr/pgmspace.h>
  21 #include <avr/interrupt.h>
  22 #include <avr/io.h>
  23 #include "print.h"
  24 #include "audio.h"
  25 #include "keymap.h"
  26
  27 #include "eeconfig.h"
  28
  29 #define CPU_PRESCALER 8
  30
  31 // -----------------------------------------------------------------------------
  32 // Timer Abstractions
  33 // -----------------------------------------------------------------------------
  34
  35 // TIMSK3 - Timer/Counter #3 Interrupt Mask Register
  36 // Turn on/off 3A interputs, stopping/enabling the ISR calls
  37 #ifdef C6_AUDIO
  38     #define ENABLE_AUDIO_COUNTER_3_ISR TIMSK3 |= _BV(OCIE3A)
  39     #define DISABLE_AUDIO_COUNTER_3_ISR TIMSK3 &= ~_BV(OCIE3A)
  40 #endif
  41
  42 #ifdef B5_AUDIO
  43     #define ENABLE_AUDIO_COUNTER_1_ISR TIMSK1 |= _BV(OCIE1A)
  44     #define DISABLE_AUDIO_COUNTER_1_ISR TIMSK1 &= ~_BV(OCIE1A)
  45 #endif
  46
  47 // TCCR3A: Timer/Counter #3 Control Register
  48 // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
  49
  50 #ifdef C6_AUDIO
  51     #define ENABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A |= _BV(COM3A1);
  52     #define DISABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A &= ~(_BV(COM3A1) | _BV(COM3A0));
  53 #endif
  54
  55 #ifdef B5_AUDIO
  56     #define ENABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A |= _BV(COM1A1);
  57     #define DISABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A &= ~(_BV(COM1A1) | _BV(COM1A0));
  58 #endif
  59
  60 // Fast PWM Mode Controls
  61
  62 #ifdef C6_AUDIO
  63     #define TIMER_3_PERIOD     ICR3
  64     #define TIMER_3_DUTY_CYCLE OCR3A
  65 #endif
  66
  67 #ifdef B5_AUDIO
  68     #define TIMER_1_PERIOD     ICR1
  69     #define TIMER_1_DUTY_CYCLE OCR1A
  70 #endif
  71
  72
  73 // -----------------------------------------------------------------------------
  74
  75
  76 int voices = 0;
  77 int voice_place = 0;
  78 float frequency = 0;
  79 float frequency_alt = 0;
  80 int volume = 0;
  81 long position = 0;
  82
  83 float frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  84 int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  85 bool sliding = false;
  86
  87 float place = 0;
  88
  89 uint8_t * sample;
  90 uint16_t sample_length = 0;
  91
  92 bool     playing_notes = false;
  93 bool     playing_note = false;
  94 float    note_frequency = 0;
  95 float    note_length = 0;
  96 uint8_t  note_tempo = TEMPO_DEFAULT;
  97 float    note_timbre = TIMBRE_DEFAULT;
  98 uint16_t note_position = 0;
  99 float (* notes_pointer)[][2];
 100 uint16_t notes_count;
 101 bool     notes_repeat;
 102 float    notes_rest;
 103 bool     note_resting = false;
 104
 105 uint8_t current_note = 0;
 106 uint8_t rest_counter = 0;
 107
 108 #ifdef VIBRATO_ENABLE
 109 float vibrato_counter = 0;
 110 float vibrato_strength = .5;
 111 float vibrato_rate = 0.125;
 112 #endif
 113
 114 float polyphony_rate = 0;
 115
 116 static bool audio_initialized = false;
 117
 118 audio_config_t audio_config;
 119
 120 uint16_t envelope_index = 0;
 121 bool glissando = true;
 122
 123 #ifndef STARTUP_SONG
 124     #define STARTUP_SONG SONG(STARTUP_SOUND)
 125 #endif
 126 float startup_song[][2] = STARTUP_SONG;
 127
 128 void audio_init()
 129 {
 130
 131     if (audio_initialized)
 132         return;
 133
 134     // Check EEPROM
 135     if (!eeconfig_is_enabled())
 136     {
 137         eeconfig_init();
 138     }
 139     audio_config.raw = eeconfig_read_audio();
 140
 141     // Set port PC6 (OC3A and /OC4A) as output
 142
 143     #ifdef C6_AUDIO
 144         DDRC |= _BV(PORTC6);
 145     #else
 146         DDRC |= _BV(PORTC6);
 147         PORTC &= ~_BV(PORTC6);
 148     #endif
 149
 150     #ifdef B5_AUDIO
 151         DDRB |= _BV(PORTB5);
 152     #else
 153         DDRB |= _BV(PORTB5);
 154         PORTB &= ~_BV(PORTB5);
 155     #endif
 156
 157     #ifdef C6_AUDIO
 158         DISABLE_AUDIO_COUNTER_3_ISR;
 159     #endif
 160
 161     #ifdef B5_AUDIO
 162         DISABLE_AUDIO_COUNTER_1_ISR;
 163     #endif
 164
 165     // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers
 166     // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
 167     // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14 (Period = ICR3, Duty Cycle = OCR3A)
 168     // Clock Select (CS3n) = 0b010 = Clock / 8
 169
 170     #ifdef C6_AUDIO
 171         TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
 172         TCCR3B = (1 << WGM33)  | (1 << WGM32)  | (0 << CS32)  | (1 << CS31) | (0 << CS30);
 173     #endif
 174
 175     #ifdef B5_AUDIO
 176         TCCR1A = (0 << COM1A1) | (0 << COM1A0) | (1 << WGM11) | (0 << WGM10);
 177         TCCR1B = (1 << WGM13)  | (1 << WGM12)  | (0 << CS12)  | (1 << CS11) | (0 << CS10);
 178     #endif
 179
 180     audio_initialized = true;
 181
 182     if (audio_config.enable) {
 183         PLAY_NOTE_ARRAY(startup_song, false, LEGATO);
 184     }
 185
 186 }
 187
 188 void stop_all_notes()
 189 {
 190     dprintf("audio stop all notes");
 191
 192     if (!audio_initialized) {
 193         audio_init();
 194     }
 195     voices = 0;
 196
 197
 198     #ifdef C6_AUDIO
 199         DISABLE_AUDIO_COUNTER_3_ISR;
 200         DISABLE_AUDIO_COUNTER_3_OUTPUT;
 201     #endif
 202
 203     #ifdef B5_AUDIO
 204         DISABLE_AUDIO_COUNTER_1_ISR;
 205         DISABLE_AUDIO_COUNTER_1_OUTPUT;
 206     #endif
 207
 208     playing_notes = false;
 209     playing_note = false;
 210     frequency = 0;
 211     frequency_alt = 0;
 212     volume = 0;
 213
 214     for (uint8_t i = 0; i < 8; i++)
 215     {
 216         frequencies[i] = 0;
 217         volumes[i] = 0;
 218     }
 219 }
 220
 221 void stop_note(float freq)
 222 {
 223     dprintf("audio stop note freq=%d", (int)freq);
 224
 225     if (playing_note) {
 226         if (!audio_initialized) {
 227             audio_init();
 228         }
 229         for (int i = 7; i >= 0; i--) {
 230             if (frequencies[i] == freq) {
 231                 frequencies[i] = 0;
 232                 volumes[i] = 0;
 233                 for (int j = i; (j < 7); j++) {
 234                     frequencies[j] = frequencies[j+1];
 235                     frequencies[j+1] = 0;
 236                     volumes[j] = volumes[j+1];
 237                     volumes[j+1] = 0;
 238                 }
 239                 break;
 240             }
 241         }
 242         voices--;
 243         if (voices < 0)
 244             voices = 0;
 245         if (voice_place >= voices) {
 246             voice_place = 0;
 247         }
 248         if (voices == 0) {
 249             #ifdef C6_AUDIO
 250                 DISABLE_AUDIO_COUNTER_3_ISR;
 251                 DISABLE_AUDIO_COUNTER_3_OUTPUT;
 252             #endif
 253             #ifdef B5_AUDIO
 254                 DISABLE_AUDIO_COUNTER_1_ISR;
 255                 DISABLE_AUDIO_COUNTER_1_OUTPUT;
 256             #endif
 257             frequency = 0;
 258             frequency_alt = 0;
 259             volume = 0;
 260             playing_note = false;
 261         }
 262     }
 263 }
 264
 265 #ifdef VIBRATO_ENABLE
 266
 267 float mod(float a, int b)
 268 {
 269     float r = fmod(a, b);
 270     return r < 0 ? r + b : r;
 271 }
 272
 273 float vibrato(float average_freq) {
 274     #ifdef VIBRATO_STRENGTH_ENABLE
 275         float vibrated_freq = average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength);
 276     #else
 277         float vibrated_freq = average_freq * vibrato_lut[(int)vibrato_counter];
 278     #endif
 279     vibrato_counter = mod((vibrato_counter + vibrato_rate * (1.0 + 440.0/average_freq)), VIBRATO_LUT_LENGTH);
 280     return vibrated_freq;
 281 }
 282
 283 #endif
 284
 285 #ifdef C6_AUDIO
 286 ISR(TIMER3_COMPA_vect)
 287 {
 288     float freq;
 289
 290     if (playing_note) {
 291         if (voices > 0) {
 292
 293             #ifdef B5_AUDIO
 294             float freq_alt = 0;
 295                 if (voices > 1) {
 296                     if (polyphony_rate == 0) {
 297                         if (glissando) {
 298                             if (frequency_alt != 0 && frequency_alt < frequencies[voices - 2] && frequency_alt < frequencies[voices - 2] * pow(2, -440/frequencies[voices - 2]/12/2)) {
 299                                 frequency_alt = frequency_alt * pow(2, 440/frequency_alt/12/2);
 300                             } else if (frequency_alt != 0 && frequency_alt > frequencies[voices - 2] && frequency_alt > frequencies[voices - 2] * pow(2, 440/frequencies[voices - 2]/12/2)) {
 301                                 frequency_alt = frequency_alt * pow(2, -440/frequency_alt/12/2);
 302                             } else {
 303                                 frequency_alt = frequencies[voices - 2];
 304                             }
 305                         } else {
 306                             frequency_alt = frequencies[voices - 2];
 307                         }
 308
 309                         #ifdef VIBRATO_ENABLE
 310                             if (vibrato_strength > 0) {
 311                                 freq_alt = vibrato(frequency_alt);
 312                             } else {
 313                                 freq_alt = frequency_alt;
 314                             }
 315                         #else
 316                             freq_alt = frequency_alt;
 317                         #endif
 318                     }
 319
 320                     if (envelope_index < 65535) {
 321                         envelope_index++;
 322                     }
 323
 324                     freq_alt = voice_envelope(freq_alt);
 325
 326                     if (freq_alt < 30.517578125) {
 327                         freq_alt = 30.52;
 328                     }
 329
 330                     TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq_alt * CPU_PRESCALER));
 331                     TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq_alt * CPU_PRESCALER)) * note_timbre);
 332                 }
 333             #endif
 334
 335             if (polyphony_rate > 0) {
 336                 if (voices > 1) {
 337                     voice_place %= voices;
 338                     if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
 339                         voice_place = (voice_place + 1) % voices;
 340                         place = 0.0;
 341                     }
 342                 }
 343
 344                 #ifdef VIBRATO_ENABLE
 345                     if (vibrato_strength > 0) {
 346                         freq = vibrato(frequencies[voice_place]);
 347                     } else {
 348                         freq = frequencies[voice_place];
 349                     }
 350                 #else
 351                     freq = frequencies[voice_place];
 352                 #endif
 353             } else {
 354                 if (glissando) {
 355                     if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
 356                         frequency = frequency * pow(2, 440/frequency/12/2);
 357                     } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
 358                         frequency = frequency * pow(2, -440/frequency/12/2);
 359                     } else {
 360                         frequency = frequencies[voices - 1];
 361                     }
 362                 } else {
 363                     frequency = frequencies[voices - 1];
 364                 }
 365
 366                 #ifdef VIBRATO_ENABLE
 367                     if (vibrato_strength > 0) {
 368                         freq = vibrato(frequency);
 369                     } else {
 370                         freq = frequency;
 371                     }
 372                 #else
 373                     freq = frequency;
 374                 #endif
 375             }
 376
 377             if (envelope_index < 65535) {
 378                 envelope_index++;
 379             }
 380
 381             freq = voice_envelope(freq);
 382
 383             if (freq < 30.517578125) {
 384                 freq = 30.52;
 385             }
 386
 387             TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 388             TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 389         }
 390     }
 391
 392     if (playing_notes) {
 393         if (note_frequency > 0) {
 394             #ifdef VIBRATO_ENABLE
 395                 if (vibrato_strength > 0) {
 396                     freq = vibrato(note_frequency);
 397                 } else {
 398                     freq = note_frequency;
 399                 }
 400             #else
 401                     freq = note_frequency;
 402             #endif
 403
 404             if (envelope_index < 65535) {
 405                 envelope_index++;
 406             }
 407             freq = voice_envelope(freq);
 408
 409             TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 410             TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 411         } else {
 412             TIMER_3_PERIOD = 0;
 413             TIMER_3_DUTY_CYCLE = 0;
 414         }
 415
 416         note_position++;
 417         bool end_of_note = false;
 418         if (TIMER_3_PERIOD > 0) {
 419             end_of_note = (note_position >= (note_length / TIMER_3_PERIOD * 0xFFFF));
 420         } else {
 421             end_of_note = (note_position >= (note_length * 0x7FF));
 422         }
 423
 424         if (end_of_note) {
 425             current_note++;
 426             if (current_note >= notes_count) {
 427                 if (notes_repeat) {
 428                     current_note = 0;
 429                 } else {
 430                     DISABLE_AUDIO_COUNTER_3_ISR;
 431                     DISABLE_AUDIO_COUNTER_3_OUTPUT;
 432                     playing_notes = false;
 433                     return;
 434                 }
 435             }
 436             if (!note_resting && (notes_rest > 0)) {
 437                 note_resting = true;
 438                 note_frequency = 0;
 439                 note_length = notes_rest;
 440                 current_note--;
 441             } else {
 442                 note_resting = false;
 443                 envelope_index = 0;
 444                 note_frequency = (*notes_pointer)[current_note][0];
 445                 note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 446             }
 447
 448             note_position = 0;
 449         }
 450     }
 451
 452     if (!audio_config.enable) {
 453         playing_notes = false;
 454         playing_note = false;
 455     }
 456 }
 457 #endif
 458
 459 #ifdef B5_AUDIO
 460 ISR(TIMER1_COMPA_vect)
 461 {
 462     #if defined(B5_AUDIO) && !defined(C6_AUDIO)
 463     float freq = 0;
 464
 465     if (playing_note) {
 466         if (voices > 0) {
 467             if (polyphony_rate > 0) {
 468                 if (voices > 1) {
 469                     voice_place %= voices;
 470                     if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
 471                         voice_place = (voice_place + 1) % voices;
 472                         place = 0.0;
 473                     }
 474                 }
 475
 476                 #ifdef VIBRATO_ENABLE
 477                     if (vibrato_strength > 0) {
 478                         freq = vibrato(frequencies[voice_place]);
 479                     } else {
 480                         freq = frequencies[voice_place];
 481                     }
 482                 #else
 483                     freq = frequencies[voice_place];
 484                 #endif
 485             } else {
 486                 if (glissando) {
 487                     if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
 488                         frequency = frequency * pow(2, 440/frequency/12/2);
 489                     } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
 490                         frequency = frequency * pow(2, -440/frequency/12/2);
 491                     } else {
 492                         frequency = frequencies[voices - 1];
 493                     }
 494                 } else {
 495                     frequency = frequencies[voices - 1];
 496                 }
 497
 498                 #ifdef VIBRATO_ENABLE
 499                     if (vibrato_strength > 0) {
 500                         freq = vibrato(frequency);
 501                     } else {
 502                         freq = frequency;
 503                     }
 504                 #else
 505                     freq = frequency;
 506                 #endif
 507             }
 508
 509             if (envelope_index < 65535) {
 510                 envelope_index++;
 511             }
 512
 513             freq = voice_envelope(freq);
 514
 515             if (freq < 30.517578125) {
 516                 freq = 30.52;
 517             }
 518
 519             TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 520             TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 521         }
 522     }
 523
 524     if (playing_notes) {
 525         if (note_frequency > 0) {
 526             #ifdef VIBRATO_ENABLE
 527                 if (vibrato_strength > 0) {
 528                     freq = vibrato(note_frequency);
 529                 } else {
 530                     freq = note_frequency;
 531                 }
 532             #else
 533                     freq = note_frequency;
 534             #endif
 535
 536             if (envelope_index < 65535) {
 537                 envelope_index++;
 538             }
 539             freq = voice_envelope(freq);
 540
 541             TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 542             TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 543         } else {
 544             TIMER_1_PERIOD = 0;
 545             TIMER_1_DUTY_CYCLE = 0;
 546         }
 547
 548         note_position++;
 549         bool end_of_note = false;
 550         if (TIMER_1_PERIOD > 0) {
 551             end_of_note = (note_position >= (note_length / TIMER_1_PERIOD * 0xFFFF));
 552         } else {
 553             end_of_note = (note_position >= (note_length * 0x7FF));
 554         }
 555
 556         if (end_of_note) {
 557             current_note++;
 558             if (current_note >= notes_count) {
 559                 if (notes_repeat) {
 560                     current_note = 0;
 561                 } else {
 562                     DISABLE_AUDIO_COUNTER_1_ISR;
 563                     DISABLE_AUDIO_COUNTER_1_OUTPUT;
 564                     playing_notes = false;
 565                     return;
 566                 }
 567             }
 568             if (!note_resting && (notes_rest > 0)) {
 569                 note_resting = true;
 570                 note_frequency = 0;
 571                 note_length = notes_rest;
 572                 current_note--;
 573             } else {
 574                 note_resting = false;
 575                 envelope_index = 0;
 576                 note_frequency = (*notes_pointer)[current_note][0];
 577                 note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 578             }
 579
 580             note_position = 0;
 581         }
 582     }
 583
 584     if (!audio_config.enable) {
 585         playing_notes = false;
 586         playing_note = false;
 587     }
 588 #endif
 589 }
 590 #endif
 591
 592 void play_note(float freq, int vol) {
 593
 594     dprintf("audio play note freq=%d vol=%d", (int)freq, vol);
 595
 596     if (!audio_initialized) {
 597         audio_init();
 598     }
 599
 600     if (audio_config.enable && voices < 8) {
 601         #ifdef C6_AUDIO
 602             DISABLE_AUDIO_COUNTER_3_ISR;
 603         #endif
 604         #ifdef B5_AUDIO
 605             DISABLE_AUDIO_COUNTER_1_ISR;
 606         #endif
 607
 608         // Cancel notes if notes are playing
 609         if (playing_notes)
 610             stop_all_notes();
 611
 612         playing_note = true;
 613
 614         envelope_index = 0;
 615
 616         if (freq > 0) {
 617             frequencies[voices] = freq;
 618             volumes[voices] = vol;
 619             voices++;
 620         }
 621
 622         #ifdef C6_AUDIO
 623             ENABLE_AUDIO_COUNTER_3_ISR;
 624             ENABLE_AUDIO_COUNTER_3_OUTPUT;
 625         #endif
 626         #ifdef B5_AUDIO
 627             #ifdef C6_AUDIO
 628             if (voices > 1) {
 629                 ENABLE_AUDIO_COUNTER_1_ISR;
 630                 ENABLE_AUDIO_COUNTER_1_OUTPUT;
 631             }
 632             #else
 633             ENABLE_AUDIO_COUNTER_1_ISR;
 634             ENABLE_AUDIO_COUNTER_1_OUTPUT;
 635             #endif
 636         #endif
 637     }
 638
 639 }
 640
 641 void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat, float n_rest)
 642 {
 643
 644     if (!audio_initialized) {
 645         audio_init();
 646     }
 647
 648     if (audio_config.enable) {
 649
 650         #ifdef C6_AUDIO
 651             DISABLE_AUDIO_COUNTER_3_ISR;
 652         #endif
 653         #ifdef B5_AUDIO
 654             DISABLE_AUDIO_COUNTER_1_ISR;
 655         #endif
 656
 657         // Cancel note if a note is playing
 658         if (playing_note)
 659             stop_all_notes();
 660
 661         playing_notes = true;
 662
 663         notes_pointer = np;
 664         notes_count = n_count;
 665         notes_repeat = n_repeat;
 666         notes_rest = n_rest;
 667
 668         place = 0;
 669         current_note = 0;
 670
 671         note_frequency = (*notes_pointer)[current_note][0];
 672         note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 673         note_position = 0;
 674
 675
 676         #ifdef C6_AUDIO
 677             ENABLE_AUDIO_COUNTER_3_ISR;
 678             ENABLE_AUDIO_COUNTER_3_OUTPUT;
 679         #endif
 680         #ifdef B5_AUDIO
 681             #ifndef C6_AUDIO
 682             ENABLE_AUDIO_COUNTER_1_ISR;
 683             ENABLE_AUDIO_COUNTER_1_OUTPUT;
 684             #endif
 685         #endif
 686     }
 687
 688 }
 689
 690 bool is_playing_notes(void) {
 691     return playing_notes;
 692 }
 693
 694 bool is_audio_on(void) {
 695     return (audio_config.enable != 0);
 696 }
 697
 698 void audio_toggle(void) {
 699     audio_config.enable ^= 1;
 700     eeconfig_update_audio(audio_config.raw);
 701     if (audio_config.enable)
 702         audio_on_user();
 703 }
 704
 705 void audio_on(void) {
 706     audio_config.enable = 1;
 707     eeconfig_update_audio(audio_config.raw);
 708     audio_on_user();
 709 }
 710
 711 void audio_off(void) {
 712     audio_config.enable = 0;
 713     eeconfig_update_audio(audio_config.raw);
 714 }
 715
 716 #ifdef VIBRATO_ENABLE
 717
 718 // Vibrato rate functions
 719
 720 void set_vibrato_rate(float rate) {
 721     vibrato_rate = rate;
 722 }
 723
 724 void increase_vibrato_rate(float change) {
 725     vibrato_rate *= change;
 726 }
 727
 728 void decrease_vibrato_rate(float change) {
 729     vibrato_rate /= change;
 730 }
 731
 732 #ifdef VIBRATO_STRENGTH_ENABLE
 733
 734 void set_vibrato_strength(float strength) {
 735     vibrato_strength = strength;
 736 }
 737
 738 void increase_vibrato_strength(float change) {
 739     vibrato_strength *= change;
 740 }
 741
 742 void decrease_vibrato_strength(float change) {
 743     vibrato_strength /= change;
 744 }
 745
 746 #endif  /* VIBRATO_STRENGTH_ENABLE */
 747
 748 #endif /* VIBRATO_ENABLE */
 749
 750 // Polyphony functions
 751
 752 void set_polyphony_rate(float rate) {
 753     polyphony_rate = rate;
 754 }
 755
 756 void enable_polyphony() {
 757     polyphony_rate = 5;
 758 }
 759
 760 void disable_polyphony() {
 761     polyphony_rate = 0;
 762 }
 763
 764 void increase_polyphony_rate(float change) {
 765     polyphony_rate *= change;
 766 }
 767
 768 void decrease_polyphony_rate(float change) {
 769     polyphony_rate /= change;
 770 }
 771
 772 // Timbre function
 773
 774 void set_timbre(float timbre) {
 775     note_timbre = timbre;
 776 }
 777
 778 // Tempo functions
 779
 780 void set_tempo(uint8_t tempo) {
 781     note_tempo = tempo;
 782 }
 783
 784 void decrease_tempo(uint8_t tempo_change) {
 785     note_tempo += tempo_change;
 786 }
 787
 788 void increase_tempo(uint8_t tempo_change) {
 789     if (note_tempo - tempo_change < 10) {
 790         note_tempo = 10;
 791     } else {
 792         note_tempo -= tempo_change;
 793     }
 794 }