Mp3 Alexa Integrated

/*
 */

#include <SDHCI.h>
#include <Audio.h>


SDClass theSD;
AudioClass *theAudio;

File myFile;

bool ErrEnd = false;
int lastVolumeValue = 0;

const int STOPPING = 0;
const int PLAYING = 1;
const int SETUP = 2;
int MODE = SETUP;
unsigned long lastPressedButton = -1L;
int fileIdx = 0;
bool isAlexaControlled = false;
/**
 * @brief Audio attention callback
 *
 * When audio internal error occurc, this function will be called back.
 */

static void audio_attention_cb(const ErrorAttentionParam *atprm)
{
  puts("Attention!");
  
  if (atprm->error_code >= AS_ATTENTION_CODE_WARNING)
    {
      ErrEnd = true;
   }
}

/**
 * @brief Setup audio player to play mp3 file
 *
 * Set clock mode to normal <br>
 * Set output device to speaker <br>
 * Set main player to decode stereo mp3. Stream sample rate is set to "auto detect" <br>
 * System directory "/mnt/sd0/BIN" will be searched for MP3 decoder (MP3DEC file)
 * Open "Sound.mp3" file <br>
 * Set master volume to -16.0 dB
 */
void setup() {
  Serial.begin(115200);

  // start audio system
  theAudio = AudioClass::getInstance();
  theAudio->begin(audio_attention_cb);

  puts("initialization Audio Library");

  /* Set clock mode to normal */
  theAudio->setRenderingClockMode(AS_CLKMODE_NORMAL);
  theAudio->setPlayerMode(AS_SETPLAYER_OUTPUTDEVICE_SPHP, AS_SP_DRV_MODE_LINEOUT);

  pinMode(2, INPUT); //NEXTBUTTON
  pinMode(3, INPUT); //STOP/START current
  pinMode(4, INPUT); //ALEXA

}

void playNextFile() {
  /* Send first frames to be decoded */
  err_t err = theAudio->initPlayer(AudioClass::Player0, AS_CODECTYPE_MP3, "/mnt/sd0/BIN", AS_SAMPLINGRATE_AUTO, AS_CHANNEL_STEREO);

  /* Verify player initialize */
  if (err != AUDIOLIB_ECODE_OK)
    {
      printf("Player0 initialize error\n");
      exit(1);
    }
  lastVolumeValue = volumeControlValue();
  theAudio->setVolume(lastVolumeValue); //more close to 0.. is HIGHER .. -300 is normal sound..
  loadSDFile();
  MODE = PLAYING;
  myFile.seek(0);
  
  err = theAudio->writeFrames(AudioClass::Player0, myFile);
  if ((err != AUDIOLIB_ECODE_OK) && (err != AUDIOLIB_ECODE_FILEEND)) {
      printf("File Read Error! =%d\n",err);
      myFile.close();
      exit(1);
  }
  theAudio->startPlayer(AudioClass::Player0);
}

void playCurrentFile(){
  myFile.seek(0);
  
  err_t err = theAudio->writeFrames(AudioClass::Player0, myFile);
  if ((err != AUDIOLIB_ECODE_OK) && (err != AUDIOLIB_ECODE_FILEEND)) {
      printf("File Read Error! =%d\n",err);
      myFile.close();
      exit(1);
  }
  theAudio->startPlayer(AudioClass::Player0);
}

int volumeControlValue() {
  int sensorValue = analogRead(A0); // 0 and 1000 value.
  return (-0.6 * sensorValue); //a value between -20 and -600
}

int checkButtons() {
  int firstButton = digitalRead(2);
  int secondButton = digitalRead(3);
  int FROMALEXA = digitalRead(4);

  //print out the value of the pushbutton
  unsigned long currentTime = millis();
  if ( currentTime - lastPressedButton > 1000L ) {
    lastPressedButton = currentTime;
    if ( firstButton == HIGH ) {

      if ( MODE == PLAYING ) { //STOP IT
        MODE = STOPPING; 
      } else if ( MODE == SETUP ){ //PLAY NEXT SONG
        MODE = PLAYING;
        myFile.seek(0);
        playNextFile();        
      }

      puts("pressed first button");
      char z[10];
      sprintf(z,"ACTUALMODE: %d",MODE);
      puts(z);
    }
    if ( secondButton == HIGH ) {
      if ( MODE == PLAYING ) { //STOP IT
        MODE = STOPPING; 
      } else if ( MODE == SETUP ){ //PLAY AGAIN
        MODE = PLAYING;
        playCurrentFile();
      }
    }
    if ( FROMALEXA == LOW) { //ALEXA SWITCHON!      
      isAlexaControlled = true;
      if ( MODE == SETUP ) {
        puts("ALEXA LOW");
        MODE = PLAYING;
        myFile.seek(0);
        playNextFile();
      }
    } else {
      if ( isAlexaControlled ) {
        puts("ALEXA HIGH ");
        if ( MODE == PLAYING ) { //STOP IT
          MODE = STOPPING; 
        }
      }
    }
  }
}

void loadSDFile() {
  puts("Size\tFilename");
  Serial.println("----\t--------");
  File root = theSD.open("/");
  int current = 0;
  bool fileFound = false;
  while (true) {
    File entry = root.openNextFile();
    if (!entry) {
      break;
    }
    String fname = entry.name();
    /*
    738331  /song1.mp3
    4096    /._song1.mp3
    6010879 /song2.mp3
    0       /BIN
    */
    if( fname.charAt(1) != '.' && fname.endsWith(".mp3") ) { //only mp3 files..
      Serial.print(entry.size(), DEC);
      Serial.print("\t");
      Serial.println(entry.name());
      if ( current == fileIdx ) {       
        if( myFile != NULL ) 
          myFile.close();
        myFile = theSD.open(fname);
        entry.close();
        fileIdx = current + 1;
        Serial.println("play this file.");
        fileFound = true;
        break;
      } else {
        current ++;
      }
    } 
    entry.close();
  }
  if ( fileFound == false ) { //read the first file..
      fileIdx = 0;
      loadSDFile();
      Serial.println("Reading from the beginning...");
  }
}

/**
 * @brief Play stream
 *
 * Send new frames to decode in a loop until file ends
 */
void loop()
{

  /* Send new frames to decode in a loop until file ends */

  if( MODE == STOPPING ) { //STOP MODE    
    theAudio->stopPlayer(AudioClass::Player0,0);
    MODE = SETUP;
    return;
  }
  checkButtons();
  if ( MODE == SETUP ) { //PLAY AGAIN 
    //maybe we can update LCD.... 
    //we can do stuff here..
    return;
  }
    
  //puts("loop");
  int err = theAudio->writeFrames(AudioClass::Player0, myFile);
  int tempVolume = volumeControlValue();

  /*  Tell when player file ends */
  if (err == AUDIOLIB_ECODE_FILEEND){
    printf("Main player File End!\n");
    theAudio->stopPlayer(AudioClass::Player0,0);
    myFile.close();
    
    playNextFile();
    return;
  }

  /* Show error code from player and stop */
  if (err)
    {
      printf("Main player error code: %d\n", err);
      //playNextFile();
    }

  if (ErrEnd)
    {
      printf("Error End\n");
      goto stop_player;

    }
    
  if ( tempVolume != lastVolumeValue ) {
    theAudio->setVolume(lastVolumeValue); //more close to 0.. is HIGHER .. -300 is normal sound..
    lastVolumeValue = tempVolume;
  }
  
  /* This sleep is adjusted by the time to read the audio stream file.
     Please adjust in according with the processing contents
     being processed at the same time by Application.
  */

  usleep(40000);

  /* Don't go further and continue play */
  return;

stop_player:
  sleep(1);
  theAudio->stopPlayer(AudioClass::Player0);
  myFile.close();
  exit(1);
}