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-rw-r--r--quantum/audio/audio.c780
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diff --git a/quantum/audio/audio.c b/quantum/audio/audio.c
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+++ b/quantum/audio/audio.c
@@ -0,0 +1,780 @@
+/* Copyright 2016 Jack Humbert
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdio.h>
+#include <string.h>
+//#include <math.h>
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include "print.h"
+#include "audio.h"
+#include "keymap.h"
+
+#include "eeconfig.h"
+
+#define CPU_PRESCALER 8
+
+// -----------------------------------------------------------------------------
+// Timer Abstractions
+// -----------------------------------------------------------------------------
+
+// TIMSK3 - Timer/Counter #3 Interrupt Mask Register
+// Turn on/off 3A interputs, stopping/enabling the ISR calls
+#ifdef C6_AUDIO
+ #define ENABLE_AUDIO_COUNTER_3_ISR TIMSK3 |= _BV(OCIE3A)
+ #define DISABLE_AUDIO_COUNTER_3_ISR TIMSK3 &= ~_BV(OCIE3A)
+#endif
+
+#ifdef B5_AUDIO
+ #define ENABLE_AUDIO_COUNTER_1_ISR TIMSK1 |= _BV(OCIE1A)
+ #define DISABLE_AUDIO_COUNTER_1_ISR TIMSK1 &= ~_BV(OCIE1A)
+#endif
+
+// TCCR3A: Timer/Counter #3 Control Register
+// Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
+
+#ifdef C6_AUDIO
+ #define ENABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A |= _BV(COM3A1);
+ #define DISABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A &= ~(_BV(COM3A1) | _BV(COM3A0));
+#endif
+
+#ifdef B5_AUDIO
+ #define ENABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A |= _BV(COM1A1);
+ #define DISABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A &= ~(_BV(COM1A1) | _BV(COM1A0));
+#endif
+
+// Fast PWM Mode Controls
+
+#ifdef C6_AUDIO
+ #define TIMER_3_PERIOD ICR3
+ #define TIMER_3_DUTY_CYCLE OCR3A
+#endif
+
+#ifdef B5_AUDIO
+ #define TIMER_1_PERIOD ICR1
+ #define TIMER_1_DUTY_CYCLE OCR1A
+#endif
+
+
+// -----------------------------------------------------------------------------
+
+
+int voices = 0;
+int voice_place = 0;
+float frequency = 0;
+float frequency_alt = 0;
+int volume = 0;
+long position = 0;
+
+float frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+bool sliding = false;
+
+float place = 0;
+
+uint8_t * sample;
+uint16_t sample_length = 0;
+
+bool playing_notes = false;
+bool playing_note = false;
+float note_frequency = 0;
+float note_length = 0;
+uint8_t note_tempo = TEMPO_DEFAULT;
+float note_timbre = TIMBRE_DEFAULT;
+uint16_t note_position = 0;
+float (* notes_pointer)[][2];
+uint16_t notes_count;
+bool notes_repeat;
+float notes_rest;
+bool note_resting = false;
+
+uint8_t current_note = 0;
+uint8_t rest_counter = 0;
+
+#ifdef VIBRATO_ENABLE
+float vibrato_counter = 0;
+float vibrato_strength = .5;
+float vibrato_rate = 0.125;
+#endif
+
+float polyphony_rate = 0;
+
+static bool audio_initialized = false;
+
+audio_config_t audio_config;
+
+uint16_t envelope_index = 0;
+bool glissando = true;
+
+void audio_init()
+{
+
+ // Check EEPROM
+ if (!eeconfig_is_enabled())
+ {
+ eeconfig_init();
+ }
+ audio_config.raw = eeconfig_read_audio();
+
+ // Set port PC6 (OC3A and /OC4A) as output
+
+ #ifdef C6_AUDIO
+ DDRC |= _BV(PORTC6);
+ #else
+ DDRC |= _BV(PORTC6);
+ PORTC &= ~_BV(PORTC6);
+ #endif
+
+ #ifdef B5_AUDIO
+ DDRB |= _BV(PORTB5);
+ #else
+ DDRB |= _BV(PORTB5);
+ PORTB &= ~_BV(PORTB5);
+ #endif
+
+ #ifdef C6_AUDIO
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ #endif
+
+ #ifdef B5_AUDIO
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ #endif
+
+ // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers
+ // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
+ // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14 (Period = ICR3, Duty Cycle = OCR3A)
+ // Clock Select (CS3n) = 0b010 = Clock / 8
+
+ #ifdef C6_AUDIO
+ TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
+ TCCR3B = (1 << WGM33) | (1 << WGM32) | (0 << CS32) | (1 << CS31) | (0 << CS30);
+ #endif
+
+ #ifdef B5_AUDIO
+ TCCR1A = (0 << COM1A1) | (0 << COM1A0) | (1 << WGM11) | (0 << WGM10);
+ TCCR1B = (1 << WGM13) | (1 << WGM12) | (0 << CS12) | (1 << CS11) | (0 << CS10);
+ #endif
+
+ audio_initialized = true;
+}
+
+void stop_all_notes()
+{
+ dprintf("audio stop all notes");
+
+ if (!audio_initialized) {
+ audio_init();
+ }
+ voices = 0;
+
+
+ #ifdef C6_AUDIO
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ DISABLE_AUDIO_COUNTER_3_OUTPUT;
+ #endif
+
+ #ifdef B5_AUDIO
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ DISABLE_AUDIO_COUNTER_1_OUTPUT;
+ #endif
+
+ playing_notes = false;
+ playing_note = false;
+ frequency = 0;
+ frequency_alt = 0;
+ volume = 0;
+
+ for (uint8_t i = 0; i < 8; i++)
+ {
+ frequencies[i] = 0;
+ volumes[i] = 0;
+ }
+}
+
+void stop_note(float freq)
+{
+ dprintf("audio stop note freq=%d", (int)freq);
+
+ if (playing_note) {
+ if (!audio_initialized) {
+ audio_init();
+ }
+ 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;
+ }
+ break;
+ }
+ }
+ voices--;
+ if (voices < 0)
+ voices = 0;
+ if (voice_place >= voices) {
+ voice_place = 0;
+ }
+ if (voices == 0) {
+ #ifdef C6_AUDIO
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ DISABLE_AUDIO_COUNTER_3_OUTPUT;
+ #endif
+ #ifdef B5_AUDIO
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ DISABLE_AUDIO_COUNTER_1_OUTPUT;
+ #endif
+ frequency = 0;
+ frequency_alt = 0;
+ volume = 0;
+ playing_note = false;
+ }
+ }
+}
+
+#ifdef VIBRATO_ENABLE
+
+float mod(float a, int b)
+{
+ float r = fmod(a, b);
+ return r < 0 ? r + b : r;
+}
+
+float vibrato(float average_freq) {
+ #ifdef VIBRATO_STRENGTH_ENABLE
+ float vibrated_freq = average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength);
+ #else
+ float vibrated_freq = average_freq * vibrato_lut[(int)vibrato_counter];
+ #endif
+ vibrato_counter = mod((vibrato_counter + vibrato_rate * (1.0 + 440.0/average_freq)), VIBRATO_LUT_LENGTH);
+ return vibrated_freq;
+}
+
+#endif
+
+#ifdef C6_AUDIO
+ISR(TIMER3_COMPA_vect)
+{
+ float freq;
+
+ if (playing_note) {
+ if (voices > 0) {
+
+ #ifdef B5_AUDIO
+ float freq_alt = 0;
+ if (voices > 1) {
+ if (polyphony_rate == 0) {
+ if (glissando) {
+ if (frequency_alt != 0 && frequency_alt < frequencies[voices - 2] && frequency_alt < frequencies[voices - 2] * pow(2, -440/frequencies[voices - 2]/12/2)) {
+ frequency_alt = frequency_alt * pow(2, 440/frequency_alt/12/2);
+ } else if (frequency_alt != 0 && frequency_alt > frequencies[voices - 2] && frequency_alt > frequencies[voices - 2] * pow(2, 440/frequencies[voices - 2]/12/2)) {
+ frequency_alt = frequency_alt * pow(2, -440/frequency_alt/12/2);
+ } else {
+ frequency_alt = frequencies[voices - 2];
+ }
+ } else {
+ frequency_alt = frequencies[voices - 2];
+ }
+
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq_alt = vibrato(frequency_alt);
+ } else {
+ freq_alt = frequency_alt;
+ }
+ #else
+ freq_alt = frequency_alt;
+ #endif
+ }
+
+ if (envelope_index < 65535) {
+ envelope_index++;
+ }
+
+ freq_alt = voice_envelope(freq_alt);
+
+ if (freq_alt < 30.517578125) {
+ freq_alt = 30.52;
+ }
+
+ TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq_alt * CPU_PRESCALER));
+ TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq_alt * CPU_PRESCALER)) * note_timbre);
+ }
+ #endif
+
+ if (polyphony_rate > 0) {
+ if (voices > 1) {
+ voice_place %= voices;
+ if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
+ voice_place = (voice_place + 1) % voices;
+ place = 0.0;
+ }
+ }
+
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(frequencies[voice_place]);
+ } else {
+ freq = frequencies[voice_place];
+ }
+ #else
+ freq = frequencies[voice_place];
+ #endif
+ } else {
+ if (glissando) {
+ if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
+ frequency = frequency * pow(2, 440/frequency/12/2);
+ } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
+ frequency = frequency * pow(2, -440/frequency/12/2);
+ } else {
+ frequency = frequencies[voices - 1];
+ }
+ } else {
+ frequency = frequencies[voices - 1];
+ }
+
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(frequency);
+ } else {
+ freq = frequency;
+ }
+ #else
+ freq = frequency;
+ #endif
+ }
+
+ if (envelope_index < 65535) {
+ envelope_index++;
+ }
+
+ freq = voice_envelope(freq);
+
+ if (freq < 30.517578125) {
+ freq = 30.52;
+ }
+
+ TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
+ TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
+ }
+ }
+
+ if (playing_notes) {
+ if (note_frequency > 0) {
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(note_frequency);
+ } else {
+ freq = note_frequency;
+ }
+ #else
+ freq = note_frequency;
+ #endif
+
+ if (envelope_index < 65535) {
+ envelope_index++;
+ }
+ freq = voice_envelope(freq);
+
+ TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
+ TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
+ } else {
+ TIMER_3_PERIOD = 0;
+ TIMER_3_DUTY_CYCLE = 0;
+ }
+
+ note_position++;
+ bool end_of_note = false;
+ if (TIMER_3_PERIOD > 0) {
+ end_of_note = (note_position >= (note_length / TIMER_3_PERIOD * 0xFFFF));
+ } else {
+ end_of_note = (note_position >= (note_length * 0x7FF));
+ }
+
+ if (end_of_note) {
+ current_note++;
+ if (current_note >= notes_count) {
+ if (notes_repeat) {
+ current_note = 0;
+ } else {
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ DISABLE_AUDIO_COUNTER_3_OUTPUT;
+ playing_notes = false;
+ return;
+ }
+ }
+ if (!note_resting && (notes_rest > 0)) {
+ note_resting = true;
+ note_frequency = 0;
+ note_length = notes_rest;
+ current_note--;
+ } else {
+ note_resting = false;
+ envelope_index = 0;
+ note_frequency = (*notes_pointer)[current_note][0];
+ note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
+ }
+
+ note_position = 0;
+ }
+ }
+
+ if (!audio_config.enable) {
+ playing_notes = false;
+ playing_note = false;
+ }
+}
+#endif
+
+#ifdef B5_AUDIO
+ISR(TIMER1_COMPA_vect)
+{
+ #if defined(B5_AUDIO) && !defined(C6_AUDIO)
+ float freq = 0;
+
+ if (playing_note) {
+ if (voices > 0) {
+ if (polyphony_rate > 0) {
+ if (voices > 1) {
+ voice_place %= voices;
+ if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
+ voice_place = (voice_place + 1) % voices;
+ place = 0.0;
+ }
+ }
+
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(frequencies[voice_place]);
+ } else {
+ freq = frequencies[voice_place];
+ }
+ #else
+ freq = frequencies[voice_place];
+ #endif
+ } else {
+ if (glissando) {
+ if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
+ frequency = frequency * pow(2, 440/frequency/12/2);
+ } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
+ frequency = frequency * pow(2, -440/frequency/12/2);
+ } else {
+ frequency = frequencies[voices - 1];
+ }
+ } else {
+ frequency = frequencies[voices - 1];
+ }
+
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(frequency);
+ } else {
+ freq = frequency;
+ }
+ #else
+ freq = frequency;
+ #endif
+ }
+
+ if (envelope_index < 65535) {
+ envelope_index++;
+ }
+
+ freq = voice_envelope(freq);
+
+ if (freq < 30.517578125) {
+ freq = 30.52;
+ }
+
+ TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
+ TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
+ }
+ }
+
+ if (playing_notes) {
+ if (note_frequency > 0) {
+ #ifdef VIBRATO_ENABLE
+ if (vibrato_strength > 0) {
+ freq = vibrato(note_frequency);
+ } else {
+ freq = note_frequency;
+ }
+ #else
+ freq = note_frequency;
+ #endif
+
+ if (envelope_index < 65535) {
+ envelope_index++;
+ }
+ freq = voice_envelope(freq);
+
+ TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
+ TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
+ } else {
+ TIMER_1_PERIOD = 0;
+ TIMER_1_DUTY_CYCLE = 0;
+ }
+
+ note_position++;
+ bool end_of_note = false;
+ if (TIMER_1_PERIOD > 0) {
+ end_of_note = (note_position >= (note_length / TIMER_1_PERIOD * 0xFFFF));
+ } else {
+ end_of_note = (note_position >= (note_length * 0x7FF));
+ }
+
+ if (end_of_note) {
+ current_note++;
+ if (current_note >= notes_count) {
+ if (notes_repeat) {
+ current_note = 0;
+ } else {
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ DISABLE_AUDIO_COUNTER_1_OUTPUT;
+ playing_notes = false;
+ return;
+ }
+ }
+ if (!note_resting && (notes_rest > 0)) {
+ note_resting = true;
+ note_frequency = 0;
+ note_length = notes_rest;
+ current_note--;
+ } else {
+ note_resting = false;
+ envelope_index = 0;
+ note_frequency = (*notes_pointer)[current_note][0];
+ note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
+ }
+
+ note_position = 0;
+ }
+ }
+
+ if (!audio_config.enable) {
+ playing_notes = false;
+ playing_note = false;
+ }
+#endif
+}
+#endif
+
+void play_note(float freq, int vol) {
+
+ dprintf("audio play note freq=%d vol=%d", (int)freq, vol);
+
+ if (!audio_initialized) {
+ audio_init();
+ }
+
+ if (audio_config.enable && voices < 8) {
+ #ifdef C6_AUDIO
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ #endif
+ #ifdef B5_AUDIO
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ #endif
+
+ // Cancel notes if notes are playing
+ if (playing_notes)
+ stop_all_notes();
+
+ playing_note = true;
+
+ envelope_index = 0;
+
+ if (freq > 0) {
+ frequencies[voices] = freq;
+ volumes[voices] = vol;
+ voices++;
+ }
+
+ #ifdef C6_AUDIO
+ ENABLE_AUDIO_COUNTER_3_ISR;
+ ENABLE_AUDIO_COUNTER_3_OUTPUT;
+ #endif
+ #ifdef B5_AUDIO
+ #ifdef C6_AUDIO
+ if (voices > 1) {
+ ENABLE_AUDIO_COUNTER_1_ISR;
+ ENABLE_AUDIO_COUNTER_1_OUTPUT;
+ }
+ #else
+ ENABLE_AUDIO_COUNTER_1_ISR;
+ ENABLE_AUDIO_COUNTER_1_OUTPUT;
+ #endif
+ #endif
+ }
+
+}
+
+void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat, float n_rest)
+{
+
+ if (!audio_initialized) {
+ audio_init();
+ }
+
+ if (audio_config.enable) {
+
+ #ifdef C6_AUDIO
+ DISABLE_AUDIO_COUNTER_3_ISR;
+ #endif
+ #ifdef B5_AUDIO
+ DISABLE_AUDIO_COUNTER_1_ISR;
+ #endif
+
+ // Cancel note if a note is playing
+ if (playing_note)
+ stop_all_notes();
+
+ playing_notes = true;
+
+ notes_pointer = np;
+ notes_count = n_count;
+ notes_repeat = n_repeat;
+ notes_rest = n_rest;
+
+ place = 0;
+ current_note = 0;
+
+ note_frequency = (*notes_pointer)[current_note][0];
+ note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
+ note_position = 0;
+
+
+ #ifdef C6_AUDIO
+ ENABLE_AUDIO_COUNTER_3_ISR;
+ ENABLE_AUDIO_COUNTER_3_OUTPUT;
+ #endif
+ #ifdef B5_AUDIO
+ #ifndef C6_AUDIO
+ ENABLE_AUDIO_COUNTER_1_ISR;
+ ENABLE_AUDIO_COUNTER_1_OUTPUT;
+ #endif
+ #endif
+ }
+
+}
+
+bool is_playing_notes(void) {
+ return playing_notes;
+}
+
+bool is_audio_on(void) {
+ return (audio_config.enable != 0);
+}
+
+void audio_toggle(void) {
+ audio_config.enable ^= 1;
+ eeconfig_update_audio(audio_config.raw);
+ if (audio_config.enable)
+ audio_on_user();
+}
+
+void audio_on(void) {
+ audio_config.enable = 1;
+ eeconfig_update_audio(audio_config.raw);
+ audio_on_user();
+}
+
+void audio_off(void) {
+ audio_config.enable = 0;
+ eeconfig_update_audio(audio_config.raw);
+}
+
+#ifdef VIBRATO_ENABLE
+
+// Vibrato rate functions
+
+void set_vibrato_rate(float rate) {
+ vibrato_rate = rate;
+}
+
+void increase_vibrato_rate(float change) {
+ vibrato_rate *= change;
+}
+
+void decrease_vibrato_rate(float change) {
+ vibrato_rate /= change;
+}
+
+#ifdef VIBRATO_STRENGTH_ENABLE
+
+void set_vibrato_strength(float strength) {
+ vibrato_strength = strength;
+}
+
+void increase_vibrato_strength(float change) {
+ vibrato_strength *= change;
+}
+
+void decrease_vibrato_strength(float change) {
+ vibrato_strength /= change;
+}
+
+#endif /* VIBRATO_STRENGTH_ENABLE */
+
+#endif /* VIBRATO_ENABLE */
+
+// Polyphony functions
+
+void set_polyphony_rate(float rate) {
+ polyphony_rate = rate;
+}
+
+void enable_polyphony() {
+ polyphony_rate = 5;
+}
+
+void disable_polyphony() {
+ polyphony_rate = 0;
+}
+
+void increase_polyphony_rate(float change) {
+ polyphony_rate *= change;
+}
+
+void decrease_polyphony_rate(float change) {
+ polyphony_rate /= change;
+}
+
+// Timbre function
+
+void set_timbre(float timbre) {
+ note_timbre = timbre;
+}
+
+// Tempo functions
+
+void set_tempo(uint8_t tempo) {
+ note_tempo = tempo;
+}
+
+void decrease_tempo(uint8_t tempo_change) {
+ note_tempo += tempo_change;
+}
+
+void increase_tempo(uint8_t tempo_change) {
+ if (note_tempo - tempo_change < 10) {
+ note_tempo = 10;
+ } else {
+ note_tempo -= tempo_change;
+ }
+}