This code runs the Accelerometer, speaker , and MP3 shield. The arduino is constantly reading the coordinate values of the accelerometer and triggers an alarm sound to play when the corrdinates change more than a certain amount. It also plays a coin sound when it gets the signal from the other arduino.

alarm-code.ino

#include "SparkFunLIS3DH.h"
#include "Wire.h"
#include "SPI.h"
#include <SdFat.h>         // SDFat Library
#include <SdFatUtil.h>     // SDFat Util Library
#include <SFEMP3Shield.h>  // Mp3 Shield Library


LIS3DH myIMU; //Default constructor is I2C, addr 0x19.

int val=0;
int pinCheck= 5;
uint8_t result;
float xcord=0;
float ycord=0;
float zcord=0;
SdFat sd;
SFEMP3Shield MP3player;
const uint8_t volume = 0; // MP3 Player volume 0=max, 255=lowest (off)
const uint16_t monoMode = 1;  // Mono setting 0=off, 3=max
bool playSound= false;
char trackName[] = "track001.mp3";
char trackTwo[] = "track002.mp3";

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  delay(1000); //relax...
  Serial.println("Processor came out of reset.\n");

  pinMode(pinCheck, INPUT);
  //Call .begin() to configure the IMU
  myIMU.begin();
  /* Set up all trigger pins as inputs, with pull-ups activated: */
  initSD();  // Initialize the SD card
  initMP3Player(); // Initialize the MP3 Shield

}


void loop()
{
  val= digitalRead(pinCheck);
  xcord= myIMU.readFloatAccelX();
  ycord= myIMU.readFloatAccelY();
  zcord= myIMU.readFloatAccelZ();

if(val ==HIGH){
  Serial.println("Coin Sound is playing");
  result = MP3player.playMP3(trackTwo);
  delay(1000);
  }
  if(val ==LOW){
  Serial.println("Coin Sound dead");
  MP3player.stopTrack();
  }
  if(xcord > -.5 || xcord < -1.2){
    playSound= true;
    Serial.println("Xcordinate");
    }
   else if(ycord > .2 || ycord < -.4){
    playSound= true;
    Serial.println("Ycordinate");
    }
   else if(zcord > .6 || zcord < -.1){
    playSound= true;
    Serial.println("Zcordinate");
    }
    else{
      playSound=false; 
      MP3player.stopTrack();
      Serial.println("Play sound is false");
      }
    if(playSound == true){
      Serial.println("Play sound is true");
        Serial.println("About to play track");
        result = MP3player.playMP3(trackName);
    }
  //Get all parameters
  Serial.print("\nAccelerometer:\n");
  Serial.print(" X = ");
  Serial.println(xcord, 4);
  Serial.print(" Y = ");
  Serial.println(ycord, 4);
  Serial.print(" Z = ");
  Serial.println(zcord, 4);

  delay(1000);
}


void initSD()
{
  //Initialize the SdCard.
  if(!sd.begin(SD_SEL, SPI_HALF_SPEED)) 
    sd.initErrorHalt();
  if(!sd.chdir("/")) 
    sd.errorHalt("sd.chdir");
}

void initMP3Player()
{
  uint8_t result = MP3player.begin(); // init the mp3 player shield
  if(result != 0) // check result, see readme for error codes.
  {
    // Error checking can go here!
  }
  MP3player.setVolume(volume, volume);
  MP3player.setMonoMode(monoMode);
}