rtttl.cpp

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#include "rtttl.h"
#include <cmath>
#include "esphome/core/hal.h"
#include "esphome/core/log.h"

namespace esphome {
namespace rtttl {

static const char *const TAG = "rtttl";

static const uint32_t DOUBLE_NOTE_GAP_MS = 10;

// These values can also be found as constants in the Tone library (Tone.h)
static const uint16_t NOTES[] = {0,    262,  277,  294,  311,  330,  349,  370,  392,  415,  440,  466,  494,
                                 523,  554,  587,  622,  659,  698,  740,  784,  831,  880,  932,  988,  1047,
                                 1109, 1175, 1245, 1319, 1397, 1480, 1568, 1661, 1760, 1865, 1976, 2093, 2217,
                                 2349, 2489, 2637, 2794, 2960, 3136, 3322, 3520, 3729, 3951};

static const uint16_t I2S_SPEED = 1600;

#undef HALF_PI
static const double HALF_PI = 1.5707963267948966192313216916398;

inline double deg2rad(double degrees) {
  static const double PI_ON_180 = 4.0 * atan(1.0) / 180.0;
  return degrees * PI_ON_180;
}

void Rtttl::dump_config() { ESP_LOGCONFIG(TAG, "Rtttl"); }

void Rtttl::play(std::string rtttl) {
  this->rtttl_ = std::move(rtttl);

  this->default_duration_ = 4;
  this->default_octave_ = 6;
  this->note_duration_ = 0;

  int bpm = 63;
  uint8_t num;

  // Get name
  this->position_ = rtttl_.find(':');

  // it's somewhat documented to be up to 10 characters but let's be a bit flexible here
  if (this->position_ == std::string::npos || this->position_ > 15) {
    ESP_LOGE(TAG, "Missing ':' when looking for name.");
    return;
  }

  auto name = this->rtttl_.substr(0, this->position_);
  ESP_LOGD(TAG, "Playing song %s", name.c_str());

  // get default duration
  this->position_ = this->rtttl_.find("d=", this->position_);
  if (this->position_ == std::string::npos) {
    ESP_LOGE(TAG, "Missing 'd='");
    return;
  }
  this->position_ += 2;
  num = this->get_integer_();
  if (num > 0)
    this->default_duration_ = num;

  // get default octave
  this->position_ = this->rtttl_.find("o=", this->position_);
  if (this->position_ == std::string::npos) {
    ESP_LOGE(TAG, "Missing 'o=");
    return;
  }
  this->position_ += 2;
  num = get_integer_();
  if (num >= 3 && num <= 7)
    this->default_octave_ = num;

  // get BPM
  this->position_ = this->rtttl_.find("b=", this->position_);
  if (this->position_ == std::string::npos) {
    ESP_LOGE(TAG, "Missing b=");
    return;
  }
  this->position_ += 2;
  num = get_integer_();
  if (num != 0)
    bpm = num;

  this->position_ = this->rtttl_.find(':', this->position_);
  if (this->position_ == std::string::npos) {
    ESP_LOGE(TAG, "Missing second ':'");
    return;
  }
  this->position_++;

  // BPM usually expresses the number of quarter notes per minute
  this->wholenote_ = 60 * 1000L * 4 / bpm;  // this is the time for whole note (in milliseconds)

  this->output_freq_ = 0;
  this->last_note_ = millis();
  this->note_duration_ = 1;

#ifdef USE_SPEAKER
  this->samples_sent_ = 0;
  this->samples_count_ = 0;
#endif
}

void Rtttl::stop() {
  this->note_duration_ = 0;
#ifdef USE_OUTPUT
  if (this->output_ != nullptr) {
    this->output_->set_level(0.0);
  }
#endif
#ifdef USE_SPEAKER
  if (this->speaker_ != nullptr) {
    if (this->speaker_->is_running()) {
      this->speaker_->stop();
    }
  }
#endif
}

void Rtttl::loop() {
  if (this->note_duration_ == 0)
    return;

#ifdef USE_SPEAKER
  if (this->speaker_ != nullptr) {
    if (this->samples_sent_ != this->samples_count_) {
      SpeakerSample sample[SAMPLE_BUFFER_SIZE + 1];
      int x = 0;
      double rem = 0.0;

      while (true) {
        // Try and send out the remainder of the existing note, one per loop()

        if (this->samples_per_wave_ != 0 && this->samples_sent_ >= this->samples_gap_) {  // Play note//
          rem = ((this->samples_sent_ << 10) % this->samples_per_wave_) * (360.0 / this->samples_per_wave_);

          int16_t val = 8192 * sin(deg2rad(rem));

          sample[x].left = val;
          sample[x].right = val;

        } else {
          sample[x].left = 0;
          sample[x].right = 0;
        }

        if (x >= SAMPLE_BUFFER_SIZE || this->samples_sent_ >= this->samples_count_) {
          break;
        }
        this->samples_sent_++;
        x++;
      }
      if (x > 0) {
        int send = this->speaker_->play((uint8_t *) (&sample), x * 4);
        if (send != x * 4) {
          this->samples_sent_ -= (x - (send / 4));
        }
        return;
      }
    }
  }
#endif
#ifdef USE_OUTPUT
  if (this->output_ != nullptr && millis() - this->last_note_ < this->note_duration_)
    return;
#endif
  if (!this->rtttl_[position_]) {
    this->note_duration_ = 0;
#ifdef USE_OUTPUT
    if (this->output_ != nullptr) {
      this->output_->set_level(0.0);
    }
#endif
    ESP_LOGD(TAG, "Playback finished");
    this->on_finished_playback_callback_.call();
    return;
  }

  // align to note: most rtttl's out there does not add and space after the ',' separator but just in case...
  while (this->rtttl_[this->position_] == ',' || this->rtttl_[this->position_] == ' ')
    this->position_++;

  // first, get note duration, if available
  uint8_t num = this->get_integer_();

  if (num) {
    this->note_duration_ = this->wholenote_ / num;
  } else {
    this->note_duration_ =
        this->wholenote_ / this->default_duration_;  // we will need to check if we are a dotted note after
  }

  uint8_t note;

  switch (this->rtttl_[this->position_]) {
    case 'c':
      note = 1;
      break;
    case 'd':
      note = 3;
      break;
    case 'e':
      note = 5;
      break;
    case 'f':
      note = 6;
      break;
    case 'g':
      note = 8;
      break;
    case 'a':
      note = 10;
      break;
    case 'b':
      note = 12;
      break;
    case 'p':
    default:
      note = 0;
  }
  this->position_++;

  // now, get optional '#' sharp
  if (this->rtttl_[this->position_] == '#') {
    note++;
    this->position_++;
  }

  // now, get optional '.' dotted note
  if (this->rtttl_[this->position_] == '.') {
    this->note_duration_ += this->note_duration_ / 2;
    this->position_++;
  }

  // now, get scale
  uint8_t scale = get_integer_();
  if (scale == 0)
    scale = this->default_octave_;
  bool need_note_gap = false;

  // Now play the note
  if (note) {
    auto note_index = (scale - 4) * 12 + note;
    if (note_index < 0 || note_index >= (int) sizeof(NOTES)) {
      ESP_LOGE(TAG, "Note out of valid range");
      this->note_duration_ = 0;
      return;
    }
    auto freq = NOTES[note_index];
    need_note_gap = freq == this->output_freq_;

    // Add small silence gap between same note
    this->output_freq_ = freq;

    ESP_LOGVV(TAG, "playing note: %d for %dms", note, this->note_duration_);
  } else {
    ESP_LOGVV(TAG, "waiting: %dms", this->note_duration_);
    this->output_freq_ = 0;
  }

#ifdef USE_OUTPUT
  if (this->output_ != nullptr) {
    if (need_note_gap) {
      this->output_->set_level(0.0);
      delay(DOUBLE_NOTE_GAP_MS);
      this->note_duration_ -= DOUBLE_NOTE_GAP_MS;
    }
    if (this->output_freq_ != 0) {
      this->output_->update_frequency(this->output_freq_);
      this->output_->set_level(0.5);
    } else {
      this->output_->set_level(0.0);
    }
  }
#endif
#ifdef USE_SPEAKER
  if (this->speaker_ != nullptr) {
    this->samples_sent_ = 0;
    this->samples_count_ = (this->sample_rate_ * this->note_duration_) / I2S_SPEED;
    // Convert from frequency in Hz to high and low samples in fixed point
    if (this->output_freq_ != 0) {
      this->samples_per_wave_ = (this->sample_rate_ << 10) / this->output_freq_;
    } else {
      this->samples_per_wave_ = 0;
    }
    if (need_note_gap) {
      this->samples_gap_ = (this->sample_rate_ * DOUBLE_NOTE_GAP_MS) / I2S_SPEED;
    } else {
      this->samples_gap_ = 0;
    }
  }
#endif

  this->last_note_ = millis();
}

}  // namespace rtttl
}  // namespace esphome