breadboard.jpg

tonal.ino

const auto PLAY_BTN_PIN = 8;
const auto SAVE_BTN_PIN = 12;
const auto TONE_SELECT_PIN = A5;
const auto SPEAKER_PIN = 5;
const auto INDICATOR_LED = 13;

void setup() {
  pinMode(PLAY_BTN_PIN, INPUT);
  pinMode(SAVE_BTN_PIN, INPUT);
  pinMode(TONE_SELECT_PIN, INPUT);
  pinMode(SPEAKER_PIN, OUTPUT);
  pinMode(INDICATOR_LED, OUTPUT);
}

int get_cur_freq() {
  const int freqs[] = { 261, 277, 293, 311, 329, 349, 370, 392, 415, 440, 466, 494, 523 };
  int freq_idx = 13 * analogRead(TONE_SELECT_PIN) / 1024;
  int freq = freqs[freq_idx];
  return freq;
}

#define check_play() do { if (digitalRead(PLAY_BTN_PIN) == HIGH) goto play; } while (0)

void loop() {
  const int MAX_FREQS = 64;
  int stored_freqs[MAX_FREQS];
  int cur_len = 0;
  for (int i = 0; i < MAX_FREQS; ++i) {
    while (digitalRead(SAVE_BTN_PIN) == LOW) {
      tone(SPEAKER_PIN, get_cur_freq(), 50);
      check_play();
    }
    stored_freqs[cur_len] = get_cur_freq();
    ++cur_len;
    while (digitalRead(SAVE_BTN_PIN) == HIGH) check_play();
  }
play:
  if (cur_len == 0) {
    for (int i = 0; i < 5; ++i) {
      digitalWrite(INDICATOR_LED, HIGH);
      delay(50);
      digitalWrite(INDICATOR_LED, LOW);
      delay(50);
    }
  } else {
    digitalWrite(INDICATOR_LED, HIGH);
    delay(500);
    for (int i = 0; i < cur_len; ++i) {
      tone(SPEAKER_PIN, stored_freqs[i], 500);
      delay(500);
    }
    delay(500);
    digitalWrite(INDICATOR_LED, LOW);
  }
}