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