If you use WAV sound broadcast module, you should recorded the WAV file in the SD card in advance, and Arduino is responsible for reading uncompressed audio file from SD card, and then sent to WAV module for broadcasting.

This module can use with Arduino IDC shield, and it support plug and play.

With WAV files SD card ready, we can connect Arduino IDC shield with Arduino SD Memory module and then connect with WAV sound broadcast modules and Arduino :

 
 

In order to broadcast the wav files , we need the wavehc library (http://code.google.com/p/wavehc /). When we test, we use wavehc20101009.zip files which you can download from the wavehc's official website, or you can download our library file package here.

After downloading the wavhc library,please uncompress it and copy the waveHC file of compressed package and put it into libraries of Arduino's installation directory.
Wavhc libraries use four of the default pins of Arduino on the 2, 3, 4, and 5, but our Arduino IDC shield on the IDC - 6 seats is with Arduino 6, 7, 8, 9, so we need to revise the WavePinDefs.h file in the WaveHC, the corresponding relation for 2->9, 3->7,4->6,5->8. You can manually modify the macro definitio beginning with  MCP_DAC_ ,and you can also directly download WavePinDefs. J files that we have modified .

When we test, we use the daphc code file of examples in the wavhc compressed package, its function is constantly search the .wav file from SD card and play,
the corresponding code is :

/*
 * This example plays every .WAV file it finds on the SD card in a loop
 */
#include "WaveHC.h"
#include "WaveUtil.h"

SdReader card;    // This object holds the information for the card
FatVolume vol;    // This holds the information for the partition on the card
FatReader root;   // This holds the information for the volumes root directory
WaveHC wave;      // This is the only wave (audio) object, since we will only play one at a time

uint8_t dirLevel; // indent level for file/dir names    (for prettyprinting)
dir_t dirBuf;     // buffer for directory reads

/*
 * Define macro to put error messages in flash memory
 */
#define error(msg) error_P(PSTR(msg))

// Function definitions (we define them here, but the code is below)
void play(FatReader &dir);

//////////////////////////////////// SETUP
void setup()
{
  Serial.begin(9600);           // set up Serial library at 9600 bps for debugging

  putstring_nl("nWave test!");  // say we woke up!

  putstring("Free RAM: ");       // This can help with debugging, running out of RAM is bad
  Serial.println(FreeRam());

  //  if (!card.init(true)) { //play with 4 MHz spi if 8MHz isn't working for you
  if (!card.init()) {         //play with 8 MHz spi (default faster!)  
    error("Card init. failed!");  // Something went wrong, lets print out why
  }

  // enable optimize read - some cards may timeout. Disable if you're having problems
  card.partialBlockRead(true);

  // Now we will look for a FAT partition!
  uint8_t part;
  for (part = 0; part < 5; part++) {   // we have up to 5 slots to look in
    if (vol.init(card, part))
      break;                           // we found one, lets bail
  }
  if (part == 5) {                     // if we ended up not finding one   
    error("No valid FAT partition!");  // Something went wrong, lets print out why
  }

  // Lets tell the user about what we found
  putstring("Using partition ");
  Serial.print(part, DEC);
  putstring(", type is FAT");
  Serial.println(vol.fatType(),DEC);     // FAT16 or FAT32?

  // Try to open the root directory
  if (!root.openRoot(vol)) {
    error("Can't open root dir!");      // Something went wrong,
  }

  // Whew! We got past the tough parts.
  putstring_nl("Files found (* = fragmented):");

  // Print out all of the files in all the directories.
  root.ls(LS_R | LS_FLAG_FRAGMENTED);
}

//////////////////////////////////// LOOP
void loop()
{
  root.rewind();
  play(root);
}

/////////////////////////////////// HELPERS
/*
 * print error message and halt
 */
void error_P(const char *str)
{
  PgmPrint("Error: ");
  SerialPrint_P(str);
  sdErrorCheck();
  while(1);
}
/*
 * print error message and halt if SD I/O error, great for debugging!
 */
void sdErrorCheck(void)
{
  if (!card.errorCode()) return;
  PgmPrint("rnSD I/O error: ");
  Serial.print(card.errorCode(), HEX);
  PgmPrint(", ");
  Serial.println(card.errorData(), HEX);
  while(1);
}
/*
 * play recursively - possible stack overflow if subdirectories too nested
 */
void play(FatReader &dir)
{
  FatReader file;
  while (dir.readDir(dirBuf) > 0) {    // Read every file in the directory one at a time

    // Skip it if not a subdirectory and not a .WAV file
    if (!DIR_IS_SUBDIR(dirBuf)
         && strncmp_P((char *)&dirBuf.name[8], PSTR("WAV"), 3)) {
      continue;
    }

    Serial.println();            // clear out a new line

    for (uint8_t i = 0; i < dirLevel; i++) {
       Serial.print(' ');       // this is for prettyprinting, put spaces in front
    }
    if (!file.open(vol, dirBuf)) {        // open the file in the directory
      error("file.open failed");          // something went wrong
    }

    if (file.isDir()) {                   // check if we opened a new directory
      putstring("Subdir: ");
      printEntryName(dirBuf);
      dirLevel += 2;                      // add more spaces
      // play files in subdirectory
      play(file);                         // recursive!
      dirLevel -= 2;
    }
    else {
      // Aha! we found a file that isnt a directory
      putstring("Playing ");
      printEntryName(dirBuf);              // print it out
      if (!wave.create(file)) {            // Figure out, is it a WAV proper?
        putstring(" Not a valid WAV");     // ok skip it
      } else {
        Serial.println();                  // Hooray it IS a WAV proper!
        wave.play();                       // make some noise!

        uint8_t n = 0;
        while (wave.isplaying) {// playing occurs in interrupts, so we print dots in realtime
          putstring(".");
          if (!(++n % 32))Serial.println();
          delay(100);
        }
        sdErrorCheck();                    // everything OK?
        // if (wave.errors)Serial.println(wave.errors);     // wave decoding errors
      }
    }
  }
}

If everything is normal, now you can be able to hear the sound playing in this module through earphone or voice box.




 

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