photon-mp3.ino

#include "application.h"

/*
 *  Serial -  link between Photon and USB
 *  Serial1 - link between Photon and Nano
 */


/**************************
 *    Config defines      *
 **************************/

#define M100_1_SECOND 10
#define M100_5_SECONDS 50
#define M100_30_SECONDS 300
#define M100_1_MINUTE 600


/**************************
 *    Global variables    *
 **************************/

int next_song = 0;
int millis100 = 0;


/**************************
 *    System functions    *
 **************************/

void setup() {
  // Initialize variables
  next_song = 0;
  millis100 = 0;

  //Spark.function("writeSerial", writeSerial);
  // Initialize serials
  Serial1.begin(115200);
  Serial.begin(115200);

  // Cloud Variables
  //Particle.variable("next_song", &next_song, INT);

  // Cloud Functions
  //Particle.function("isPlaying");
  //Particle.function("setNextSong");
  Particle.function("sendSong");

}


void loop() {
  Particle.process();
  delay(100);
  millis100++;
  if(1 /* EVERY 100MS */) {
    // Check playing status
    playing = isPlaying();
  }
  if (millis100 % M100_30_SECONDS == 0) {
    // Check server status
  }
  if (millis100 % M100_1_MINUTE == 0) {
    // Check something else
  }

  /* TESTING
  if(Serial1.available()) {
    Serial.write(Serial1.read());
  }
  if (Serial.available()) {
    Serial1.write(Serial.read());
  }*/
  //delay(50);

  if (!playing) {
    if (next_song) {
      // Next song ready, play it
      playSong(next_song);
      // Clear song "queue"
      next_song = 0;
    } else {
      // No song ready, what do?
    }
  } else {
    // Currently playing a song
  }

}

/**************************
 *    Local functions     *
 **************************/

// Send CRNL-terminated string to nano-mp3
int writeSerial(String arg) {
    arg += "\r\n";
    Serial1.write(arg);
    return 1;
}

// Poll nano-mp3 for playing status
int isPlaying() {
  Serial1.write("s");
  while(!Serial1.available());
  return Serial.read();
}

// Send next song index to nano-mp3
int playSong(int _next_song) {
  Serial1.print(_next_song);
}

/***********************
 *   Cloud Functions   *
 ***********************/

// Returns value of the next song
int getNextSong() {
  return next_song;
}

// Explicitly sets next song regardless of state
int setNextSong(String _next_song) {
  // TODO: Parse integer out of string
  next_song = _next_song.toInt();
}

// Checks state and sets if no song next in queue
int sendSong(String _next_song) {
  if (next_song) {
    // Already have song in queue
    return -1;
  }
  else {
    // No song in queue
    // TODO: Parse integer out of string
    next_song = _next_song.toInt();
    return 1;
  }
}