http://work-now-dammit.blogspot.com/2016/08/dfplayer-mp3-module-power-onoff-clicks.html

or http://www.banggood.com/DFPlayer-Mini-MP3-Player-Module-For-Arduino-p-969191.html

They are also available on Amazon: https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=dfplayer

good info here: http://forum.arduino.cc/index.php?topic=241021.15#main_content_section

and here: http://translate.google.com/translate?u=http%3A%2F%2Famperka.ru%2Fproduct%2Fdf-player-mp3-module&hl=en&langpair=auto|en&tbb=1&ie=UTF-8 (translated to English)

/*
Working well from 5 volt supply - still have to work on how the files play but it 
works rather well  
d. bodnar
12-28-14
*/


/*******************************************************************************
 * DFPlayer_Mini_Mp3, This library provides a quite complete function for      * 
 * DFPlayer mini mp3 module.                                                   *
 * www.github.com/dfrobot/DFPlayer_Mini_Mp3 (github as default source provider)*
 *  DFRobot-A great source for opensource hardware and robot.                  *
 *                                                                             *
 * This file is part of the DFplayer_Mini_Mp3 library.                         *
 *                                                                             *
 * DFPlayer_Mini_Mp3 is free software: you can redistribute it and/or          *
 * modify it under the terms of the GNU Lesser General Public License as       *
 * published by the Free Software Foundation, either version 3 of              *
 * the License, or any later version.                                          *
 *                                                                             *
 * DFPlayer_Mini_Mp3 is distributed in the hope that it will be useful,        *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of              *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               *
 * GNU Lesser General Public License for more details.                         *
 *                                                                             *
 * DFPlayer_Mini_Mp3 is distributed in the hope that it will be useful,        *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of              *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               *
 * GNU Lesser General Public License for more details.                         *
 *                                                                             *
 * You should have received a copy of the GNU Lesser General Public            *
 * License along with DFPlayer_Mini_Mp3. If not, see                           *
 * <http://www.gnu.org/licenses/>.                                             *
 *									       *
 ******************************************************************************/

/*
 *	Copyright:	DFRobot
 *	name:		DFPlayer_Mini_Mp3 sample code
 *	Author:		lisper <lisper.li@dfrobot.com>
 *	Date:		2014-05-30
 *	Description:	sample code for DFPlayer Mini, this code is test on Uno
 *			note: mp3 file must put into mp3 folder in your tf card
 */

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>

//
void setup () {
	Serial.begin (9600);
	mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
	mp3_set_volume (25);          // 15 is low for unpowered speaker 
                                      // 30 good for unpowered speaker - requires power off to reset volume
}


//
void loop () {        
	mp3_play (1);
	delay (6000);
	mp3_next ();
	delay (6000);
	 mp3_next ();
	delay (6000);
	 mp3_next ();
	delay (6000);
	 mp3_next ();
	delay (6000);
	 mp3_next ();
	delay (6000);
	 
}

/*
   mp3_play ();		//start play
   mp3_play (5);	//play "mp3/0005.mp3"
   mp3_next ();		//play next 
   mp3_prev ();		//play previous
   mp3_set_volume (uint16_t volume);	//0~30
   mp3_set_EQ ();	//0~5
   mp3_pause ();
   mp3_stop ();
   void mp3_get_state (); 	//send get state command
   void mp3_get_volume (); 
   void mp3_get_u_sum (); 
   void mp3_get_tf_sum (); 
   void mp3_get_flash_sum (); 
   void mp3_get_tf_current (); 
   void mp3_get_u_current (); 
   void mp3_get_flash_current (); 
   void mp3_single_loop (boolean state);	//set single loop 
   void mp3_DAC (boolean state); 
   void mp3_random_play (); 
 */

Program with LCD output - 2 line x 16 characters

/*
Working well from 5 volt supply - still have to work on how the files play but it 
works rather well  
d. bodnar
12-28-14
*/

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27 // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7
int potPin = A3;    // select the input pin for the potentiometer
int potValue = 0;  // variable to store the value coming from the pot
byte buffer[10];
LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
//
void setup () {
	Serial.begin (9600);
	mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
        mp3_reset();
        delay (400);
	mp3_set_volume (10);          // 15 is low for unpowered speaker 
        delay (400);                             // 30 good for unpowered speaker - requires power off to reset volume
      Serial.println("     mp3-test");    

 lcd.begin (16,2); //  <<----- My LCD was 16x2
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);// Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.home (); // go home
  lcd.print("  MP3 Player");    
  // delay(1000);
  lcd.setCursor(0,1);
  lcd.print("  Version 1.0  ");
  delay (1500);
  lcd.home (); // go home
  lcd.clear();
  lcd.print("trainelectronics");    
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print(" 2014 d. bodnar");
  delay (2500);
  //lcd.home (); // go home
  //lcd.clear();
  //lcd.print(" LAPS    STATUS"); 

      
}


//
void loop () {        

  	mp3_play (1);
        Serial.println("     mp3-test -1");
	delay (1000);
  	mp3_play (3);
        Serial.println("     mp3-test -3");
	delay (1000);
  	mp3_play (7);
        Serial.println("     mp3-test -7");
	delay (1000);
  	mp3_play (12);
        Serial.println("     mp3-test -12");
	delay (1000);
  	mp3_play (10);
        Serial.println("     mp3-test -10");
	delay (61000);




/*
Serial.println("     mp3-test - next -1");
	mp3_next ();
	delay (1500);
Serial.println("     mp3-test - next -2");
	 mp3_next ();
	delay (1500);
Serial.println("     mp3-test - next -3");
	 mp3_next ();
	delay (1500);
Serial.println("     mp3-test - next -4");
	 mp3_next ();
	delay (1500);
Serial.println("     mp3-test - next -5");
	 mp3_next ();
	delay (1500);
Serial.println("     mp3-test - next - last");
 mp3_next ();
	 delay (1500);
*/
}

/*
   mp3_play ();		//start play
   mp3_play (5);	//play "mp3/0005.mp3"
   mp3_next ();		//play next 
   mp3_prev ();		//play previous
   mp3_set_volume (uint16_t volume);	//0~30
   mp3_set_EQ ();	//0~5
   mp3_pause ();
   mp3_stop ();
   void mp3_get_state (); 	//send get state command
   void mp3_get_volume (); 
   void mp3_get_u_sum (); 
   void mp3_get_tf_sum (); 
   void mp3_get_flash_sum (); 
   void mp3_get_tf_current (); 
   void mp3_get_u_current (); 
   void mp3_get_flash_current (); 
   void mp3_single_loop (boolean state);	//set single loop 
   void mp3_DAC (boolean state); 
   void mp3_random_play (); 
 */

DFPlayer_MP3_2lineLCD_18b20

/*
Working well from 5 volt supply - still have to work on how the files play but it 
works rather well  
d. bodnar
12-28-14
*/

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27 // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

#include <OneWire.h>
#include <DallasTemperature.h>

// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS 2
#define TEMPERATURE_PRECISION 9
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);

int numberOfDevices; // Number of temperature devices found

DeviceAddress tempDeviceAddress; // We'll use this variable to store a found device address



int potPin = A3;    // select the input pin for the potentiometer
int potValue = 0;  // variable to store the value coming from the pot
byte buffer[10];
LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
//
void setup () {
	Serial.begin (9600);
	mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
        mp3_reset();
        delay (400);
	mp3_set_volume (10);          // 15 is low for unpowered speaker 
        delay (400);                             // 30 good for unpowered speaker - requires power off to reset volume
      Serial.println("     mp3-test");    

 lcd.begin (16,2); //  <<----- My LCD was 16x2
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);// Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.home (); // go home
  lcd.print("  MP3 Player");    
  // delay(1000);
  lcd.setCursor(0,1);
  lcd.print("  Version 1.0  ");
  delay (1500);
  lcd.home (); // go home
  lcd.clear();
  lcd.print("trainelectronics");    
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print(" 2014 d. bodnar");
  delay (2500);
  //lcd.home (); // go home
  //lcd.clear();
  //lcd.print(" LAPS    STATUS"); 

  // Start up the library
  sensors.begin();
  
  // Grab a count of devices on the wire
  numberOfDevices = sensors.getDeviceCount();
  
  // locate devices on the bus
  Serial.print("Locating devices...");
  
  Serial.print("Found ");
  Serial.print(numberOfDevices, DEC);
  Serial.println(" devices.");

  // report parasite power requirements
  Serial.print("Parasite power is: "); 
  if (sensors.isParasitePowerMode()) Serial.println("ON");
  else Serial.println("OFF");
 // Loop through each device, print out address
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
	{
		Serial.print("Found device ");
		Serial.print(i, DEC);
		Serial.print(" with address: ");
		printAddress(tempDeviceAddress);
		Serial.println();
		
		Serial.print("Setting resolution to ");
		Serial.println(TEMPERATURE_PRECISION, DEC);
		
		// set the resolution to TEMPERATURE_PRECISION bit (Each Dallas/Maxim device is capable of several different resolutions)
		sensors.setResolution(tempDeviceAddress, TEMPERATURE_PRECISION);
		
		 Serial.print("Resolution actually set to: ");
		Serial.print(sensors.getResolution(tempDeviceAddress), DEC); 
		Serial.println();
	}else{
		Serial.print("Found ghost device at ");
		Serial.print(i, DEC);
		Serial.print(" but could not detect address. Check power and cabling");
	}
  }       
}

// function to print the temperature for a device
void printTemperature(DeviceAddress deviceAddress)
{
  // method 1 - slower
  //Serial.print("Temp C: ");
  //Serial.print(sensors.getTempC(deviceAddress));
  //Serial.print(" Temp F: ");
  //Serial.print(sensors.getTempF(deviceAddress)); // Makes a second call to getTempC and then converts to Fahrenheit

  // method 2 - faster
  float tempC = sensors.getTempC(deviceAddress);
  Serial.print("Temp C: ");
  Serial.print(tempC);
  Serial.print(" Temp F: ");
  Serial.println(DallasTemperature::toFahrenheit(tempC)); // Converts tempC to Fahrenheit
  float xtemp = DallasTemperature::toFahrenheit(tempC);
  lcd.setCursor (8,0);
  lcd.print(xtemp);
  delay(2000);
}
//
void loop () {        
      lcd.home (); // go home
      lcd.clear();
      lcd.print(" Output");    
      // delay(1000);
      lcd.setCursor(0,1);
      lcd.print(" test - 1");
  	mp3_play (1);
        Serial.println("     mp3-test -1");
	lcd.setCursor(0,1);
        lcd.print(" test - 1");
  	delay (1000);
  	mp3_play (3);
        Serial.println("     mp3-test -3");
        lcd.setCursor(0,1);
        lcd.print(" test - 3");
	delay (1000);
  	mp3_play (7);
        Serial.println("     mp3-test -7");
        lcd.setCursor(0,1);
        lcd.print(" test - 7");
	delay (1000);
  	mp3_play (12);
        Serial.println("     mp3-test -12");
        lcd.setCursor(0,1);
        lcd.print(" test - 12");
	delay (1000);
  	mp3_play (10);
        Serial.println("     mp3-test -10");
        lcd.setCursor(0,1);
        lcd.print(" test - 10");
        for (int i=0; i <= 5; i++){
          lcd.setCursor (10,0);
          lcd.print(i);
          delay(1000);
   } 
	//delay (61000);

  Serial.print("Requesting temperatures...");
  sensors.requestTemperatures(); // Send the command to get temperatures
  Serial.println("DONE");
  
  
  // Loop through each device, print out temperature data
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
	{
		// Output the device ID
		Serial.print("Temperature for device: ");
		Serial.println(i,DEC);
		
		// It responds almost immediately. Let's print out the data
		printTemperature(tempDeviceAddress); // Use a simple function to print out the data
	} 
	//else ghost device! Check your power requirements and cabling
	
  }


}
// function to print a device address
void printAddress(DeviceAddress deviceAddress)
{
  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    Serial.print(deviceAddress[i], HEX);
  }
}
 

WORKING!  Says temperature (as integer!)
DFPlayer_MP3_2lineLCD_18b20_Ver2

/*
Working well from 5 volt supply - still have to work on how the files play but it 
 works rather well  
 d. bodnar
 12-28-14
 */

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27 // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

#include <OneWire.h>
#include <DallasTemperature.h>

// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS 2
#define TEMPERATURE_PRECISION 9
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);

int numberOfDevices; // Number of temperature devices found

DeviceAddress tempDeviceAddress; // We'll use this variable to store a found device address

int value = 0; // 
float xtemp=0;
int potPin = A3;    // select the input pin for the potentiometer
int potValue = 0;  // variable to store the value coming from the pot
byte buffer[10];
LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
char buf[12]; 
//
void setup () {
  Serial.begin (9600);
  mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
  mp3_reset();
  delay (400);
  mp3_set_volume (10);          // 15 is low for unpowered speaker 
  delay (400);                             // 30 good for unpowered speaker - requires power off to reset volume
/* //  Serial.println("     mp3-test");    
  //  char buf[12]; // "-2147483648\0"
  xtemp = 9812;
  String thisString = itoa(xtemp, buf, 10);
  Serial.println(thisString);
  int lgth = thisString.length();
  Serial.println(thisString.length());
  Serial.println(lgth);
  Serial.println(itoa(xtemp, buf, 10));
  Serial.println("start");
  for (int i=0; i <= lgth; i++){
    Serial.println(thisString.substring(i,i+1));   
  }
 */ 
  lcd.begin (16,2); //  <<----- My LCD was 16x2
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);// Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.home (); // go home
  lcd.print("  MP3 Player");    
  // delay(1000);
  lcd.setCursor(0,1);
  lcd.print("  Version 1.0  ");
  delay (1500);
  lcd.home (); // go home
  lcd.clear();
  lcd.print("trainelectronics");    
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print(" 2014 d. bodnar");
  delay (2500);
   // Start up the library
  sensors.begin();

  // Grab a count of devices on the wire
  numberOfDevices = sensors.getDeviceCount();

  // locate devices on the bus
  Serial.print("Locating devices...");

  Serial.print("Found ");
  Serial.print(numberOfDevices, DEC);
  Serial.println(" devices.");

  // report parasite power requirements
  Serial.print("Parasite power is: "); 
  if (sensors.isParasitePowerMode()) Serial.println("ON");
  else Serial.println("OFF");
  // Loop through each device, print out address
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      Serial.print("Found device ");
      Serial.print(i, DEC);
      Serial.print(" with address: ");
      printAddress(tempDeviceAddress);
      Serial.println();

      Serial.print("Setting resolution to ");
      Serial.println(TEMPERATURE_PRECISION, DEC);

      // set the resolution to TEMPERATURE_PRECISION bit (Each Dallas/Maxim device is capable of several different resolutions)
      sensors.setResolution(tempDeviceAddress, TEMPERATURE_PRECISION);

      Serial.print("Resolution actually set to: ");
      Serial.print(sensors.getResolution(tempDeviceAddress), DEC); 
      Serial.println();
    }
    else{
      Serial.print("Found ghost device at ");
      Serial.print(i, DEC);
      Serial.print(" but could not detect address. Check power and cabling");
    }
  }       
}

// function to print the temperature for a device
void printTemperature(DeviceAddress deviceAddress)
{

  float tempC = sensors.getTempC(deviceAddress);
  Serial.print("Temp C: ");
  Serial.print(tempC);
  Serial.print(" Temp F: ");
  Serial.println(DallasTemperature::toFahrenheit(tempC)); // Converts tempC to Fahrenheit
  xtemp = DallasTemperature::toFahrenheit(tempC);
  lcd.setCursor (8,0);
  lcd.print(xtemp);
  delay(2000);
}
//
void loop () {        
  lcd.home (); // go home
  lcd.clear();
  lcd.print(" Output");   
  lcd.setCursor (8,0);
  lcd.print(xtemp);

  //       xtemp = 9812;
  String thisString = itoa(xtemp, buf, 10);
  Serial.println(thisString);
  int lgth = thisString.length();
  Serial.println(thisString.length());
  Serial.println(lgth);
 // Serial.println(itoa(xtemp, buf, 10));
  Serial.println("start");
  for (int i=0; i <= lgth-1; i++){
    int say = (thisString.substring(i,i+1)).toInt();
    Serial.println(thisString.substring(i,i+1)); 
    Serial.print("saying ");
    Serial.println(say); 
    if (say == 0 ){
    mp3_play(10); //zero
    }
    else{
    mp3_play(say);   
    }
    delay(1200);
    lcd.setCursor(0,1);
  }
  mp3_play(13);  //degrees
  delay (1200);
  mp3_play(14);  //fahrenheit
  delay (1200);

  Serial.print("Requesting temperatures...");
  sensors.requestTemperatures(); // Send the command to get temperatures
  Serial.println("DONE");

  // Loop through each device, print out temperature data
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      // Output the device ID
      Serial.print("Temperature for device: ");
      Serial.println(i,DEC);

      // It responds almost immediately. Let's print out the data
      printTemperature(tempDeviceAddress); // Use a simple function to print out the data
    } 
    //else ghost device! Check your power requirements and cabling

  }
}
// function to print a device address
void printAddress(DeviceAddress deviceAddress)
{
  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    Serial.print(deviceAddress[i], HEX);
  }
}

Working well - delays after talking stops till busy pin clears--1-1-15
DFPlayer_MP3_2lineLCD_18b20_Ver3_3

/*
Working well from 5 volt supply - still have to work on how the files play but it 
 works rather well  
 d. bodnar
 12-28-14
 
 TODO:  
   add pot for volume
   add button for start
   remove first play (does zero)
 
 */

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27 // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

#include <OneWire.h>
#include <DallasTemperature.h>

// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS 2
#define TEMPERATURE_PRECISION 9
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);

int numberOfDevices; // Number of temperature devices found

DeviceAddress tempDeviceAddress; // We'll use this variable to store a found device address

int value = 0; // 
float xtemp=0;
int potPin = A3;    // select the input pin for the potentiometer
int potValue = 0;  // variable to store the value coming from the pot
byte buffer[10];
LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
char buf[12]; 

const int buttonPin = 3;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin
int buttonState = 0;         // variable for reading the pushbutton status
//int potPin = A3;    // select the input pin for the potentiometer
//int potValue = 0;  // variable to store the value coming from the pot
int buusyPin = 10;// buusyPin = 10; // sound player busy
int bsy = 0;
int z=0;
//
void setup () {
  pinMode(buusyPin, INPUT);
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);      
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);   
  Serial.begin (9600);
  // 30 good for unpowered speaker - requires power off to reset volume
  /* //  Serial.println("     mp3-test");    
   //  char buf[12]; // "-2147483648\0"
   xtemp = 9812;
   String thisString = itoa(xtemp, buf, 10);
   Serial.println(thisString);
   int lgth = thisString.length();
   Serial.println(thisString.length());
   Serial.println(lgth);
   Serial.println(itoa(xtemp, buf, 10));
   Serial.println("start");
   for (int i=0; i <= lgth; i++){
   Serial.println(thisString.substring(i,i+1));   
   }
   */
  lcd.begin (16,2); //  <<----- My LCD was 16x2
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);// Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.home (); // go home
  lcd.print("  MP3 Player");    
  // delay(1000);
  lcd.setCursor(0,1);
  lcd.print("  Version 3.3  ");
  delay ( 500);
  lcd.home (); // go home
  lcd.clear();
  lcd.print("trainelectronics");    
  delay(100);
  lcd.setCursor(0,1);
  lcd.print(" 2015 d. bodnar");
  delay ( 500);
  // Start up the library


  mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
  mp3_reset();
  delay (400);
  mp3_set_volume (10);          // 15 is low for unpowered speaker 
  delay (400);  

  sensors.begin();

  // Grab a count of devices on the wire
  numberOfDevices = sensors.getDeviceCount();

  // locate devices on the bus
  Serial.print("Locating devices...");

  Serial.print("Found ");
  Serial.print(numberOfDevices, DEC);
  Serial.println(" devices.");

  // report parasite power requirements
  Serial.print("Parasite power is: "); 
  if (sensors.isParasitePowerMode()) Serial.println("ON");
  else Serial.println("OFF");
  // Loop through each device, print out address
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      Serial.print("Found device ");
      Serial.print(i, DEC);
      Serial.print(" with address: ");
      printAddress(tempDeviceAddress);
      Serial.println();

      Serial.print("Setting resolution to ");
      Serial.println(TEMPERATURE_PRECISION, DEC);

      // set the resolution to TEMPERATURE_PRECISION bit (Each Dallas/Maxim device is capable of several different resolutions)
      sensors.setResolution(tempDeviceAddress, TEMPERATURE_PRECISION);

      Serial.print("Resolution actually set to: ");
      Serial.print(sensors.getResolution(tempDeviceAddress), DEC); 
      Serial.println();
    }
    else{
      Serial.print("Found ghost device at ");
      Serial.print(i, DEC);
      Serial.print(" but could not detect address. Check power and cabling");
    }
  }       
}

// function to print the temperature for a device
void printTemperature(DeviceAddress deviceAddress)
{

  float tempC = sensors.getTempC(deviceAddress);
  Serial.print("Temp C: ");
  Serial.print(tempC);
  Serial.print(" Temp F: ");
  Serial.println(DallasTemperature::toFahrenheit(tempC)); // Converts tempC to Fahrenheit
  xtemp = DallasTemperature::toFahrenheit(tempC);
  lcd.setCursor (8,0);
  lcd.print(xtemp);
  delay(2000);
}
//
void loop () {   
  potValue = analogRead(potPin);
  Serial.print("pot= "); 
  Serial.println(potValue);

  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {     
    // turn LED on:    
    digitalWrite(ledPin, HIGH);  
  } 
  else {
    // turn LED off:
    digitalWrite(ledPin, LOW); 
  }



  lcd.home (); // go home
  lcd.clear();
  lcd.print(" Output");   
  lcd.setCursor (8,0);
  lcd.print(xtemp);

  //       xtemp = 9812;
  String thisString = itoa(xtemp, buf, 10);
  Serial.println(thisString);
  int lgth = thisString.length();
  Serial.println(thisString.length());
  Serial.println(lgth);
  // Serial.println(itoa(xtemp, buf, 10));
  Serial.println("start");
  for (int i=0; i <= lgth-1; i++){
    int say = (thisString.substring(i,i+1)).toInt();
    Serial.println(thisString.substring(i,i+1)); 
    Serial.print("saying ");
    Serial.println(say); 
    if (say == 0 ){
      mp3_play(10); //zero
    }
    else{
      mp3_play(say);   
    }
   dlayPrint();// delay(1200);
    lcd.setCursor(0,1);
  }
  mp3_play(13);  //degrees

  dlayPrint();
  //delay (1200);
  mp3_play(14);  //fahrenheit
  dlayPrint();//delay (1200);

  Serial.print("Requesting temperatures...");
  sensors.requestTemperatures(); // Send the command to get temperatures
  Serial.println("DONE");

  // Loop through each device, print out temperature data
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      // Output the device ID
      Serial.print("Temperature for device: ");
      Serial.println(i,DEC);

      // It responds almost immediately. Let's print out the data
      printTemperature(tempDeviceAddress); // Use a simple function to print out the data
    } 
    //else ghost device! Check your power requirements and cabling

  }
}

// routine to stay here till busy pin goes low once then goes high after speach item completes
void dlayPrint()
{
int bsyflag=0;
  for( z=0; z<=300; z++){
    bsy = digitalRead(buusyPin);
    Serial.print("buusypin ");
    Serial.println(bsy);
    delay(20); 
    if (bsyflag==1 && bsy==1){
    break;
    }
    if(bsy==0){
    bsyflag=1;
    }
  }
  Serial.println("done");
}

// function to print a device address
void printAddress(DeviceAddress deviceAddress)
{
  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    Serial.print(deviceAddress[i], HEX);
  }
}

Working with decimal degrees F being spoken
DFPlayer_MP3_2lineLCD_18b20_Lasers_Ver4_4_F_decimal

/*
 d. bodnar
 1-5-15
 WORKING with decimal speaking of F temperature
 Hardware wired and tested for laser & phototransistor sensors (2) on fasttrack for HO
 TODO:  
 1.  write & test routines to do axle count (only with sensor that first "sees" an axle)
 2.  consider flashing lasers to make them  less visible
 3.  write & test routine to determine speed 
 4.  write & test routine to determine length (first wheel to last, not body to body)
 5.  trigger audio report after train passes
 */

#include <SoftwareSerial.h>
#include <DFPlayer_Mini_Mp3.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27 // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 2
#define TEMPERATURE_PRECISION 9
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
int numberOfDevices; // Number of temperature devices found
DeviceAddress tempDeviceAddress; // We'll use this variable to store a found device address

int value = 0; // 
float xtemp=0;
int potPin = A3;    // select the input pin for the potentiometer
int potValue = 0;  // variable to store the value coming from the pot
byte buffer[10];
LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
char buf[12]; 
const int buttonPin = 3;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin
int buttonState = 0;         // variable for reading the pushbutton status
int buusyPin = 10;// buusyPin = 10; // sound player busy
int bsy = 0;
int z=0;
int PTState;
int Laser = 11; // laser control 
int PhotoTransistor = 9;
int PTState2;
int Laser2 = 12; // laser control 
int PhotoTransistor2 = 8;
int xCount =0;

long tempF=0;
char tempFString(12);
String thisString(12);

//
void setup () {
  pinMode(Laser, OUTPUT);
  pinMode(PhotoTransistor, INPUT);
  pinMode(Laser2, OUTPUT);
  pinMode(PhotoTransistor2, INPUT);

  pinMode(buusyPin, INPUT);
  pinMode(ledPin, OUTPUT);      
  pinMode(buttonPin, INPUT);   
  Serial.begin (9600);
  // 30 good for unpowered speaker - requires power off to reset volume
  lcd.begin (16,2); //  <<----- My LCD was 16x2
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);// Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.home (); // go home
  lcd.print("  MP3 Player");    
  delay(200);
  lcd.setCursor(0,1);
  lcd.print("  Version 4.4c  ");
  delay ( 500);
  lcd.home (); // go home
  lcd.clear();
  lcd.print("trainelectronics");    
  delay(100);
  lcd.setCursor(0,1);
  lcd.print(" 2015 d. bodnar");
  delay ( 500);
  mp3_set_serial (Serial);	//set Serial for DFPlayer-mini mp3 module 
  mp3_reset();
  delay (400);
  mp3_set_volume (30);          // 15 is low for unpowered speaker 
  delay (400);  
  sensors.begin();
  numberOfDevices = sensors.getDeviceCount();
  Serial.print("Locating devices...");
  Serial.print("Found ");
  Serial.print(numberOfDevices, DEC);
  Serial.println(" devices.");
  Serial.print("Parasite power is: "); 
  if (sensors.isParasitePowerMode()) Serial.println("ON");
  else Serial.println("OFF");
  for(int i=0;i<numberOfDevices; i++)
  {
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      Serial.print("Found device ");
      Serial.print(i, DEC);
      Serial.print(" with address: ");
      printAddress(tempDeviceAddress);
      Serial.println();
      Serial.print("Setting resolution to ");
      Serial.println(TEMPERATURE_PRECISION, DEC);
      sensors.setResolution(tempDeviceAddress, TEMPERATURE_PRECISION);
      Serial.print("Resolution actually set to: ");
      Serial.print(sensors.getResolution(tempDeviceAddress), DEC); 
      Serial.println();
    }
    else{
      Serial.print("Found ghost device at ");
      Serial.print(i, DEC);
      Serial.print(" but could not detect address. Check power and cabling");
    }
  }  
  sensors.requestTemperatures(); // Send the command to get temperatures
  printTemperature(tempDeviceAddress); // Use a simple function to print out the data
}


void loop () {   
  xCount = ++xCount;
  digitalWrite(Laser, HIGH);
  delay(10); // wait for a bit
  PTState = digitalRead(PhotoTransistor);  
  Serial.print (xCount);
  Serial.print(" ");
  Serial.print(PTState);
  Serial.print(" ");
  digitalWrite(Laser2, HIGH);
  delay(10); // wait for a bit
  PTState2 = digitalRead(PhotoTransistor2);  
  Serial.println(PTState2);
  /*
  if(PTState == 1 || PTState2 ==1){
   digitalWrite(ledPin, HIGH); 
   }
   else {
   digitalWrite (ledPin, LOW); 
   }
   */
  if(PTState == 1 && PTState2 ==1){
    digitalWrite(ledPin, HIGH); 
  }
  else {
    digitalWrite (ledPin, LOW); 
  }

  potValue = analogRead(potPin);
  Serial.print("pot= "); 
  Serial.println(potValue);
  // delay(2000);
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);
  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {     
    // turn LED on:    
    ////   digitalWrite(ledPin, HIGH);  
  } 
  else {
    // turn LED off:
    ////    digitalWrite(ledPin, LOW); 
  }

  lcd.home (); // go home
  lcd.clear();
  lcd.print(" Output");   
  lcd.setCursor (8,0);
  lcd.print(xtemp);

  // String thisString =String tempFString;
  //  String thisString = itoa(xtemp, buf, 10);
  //  convertFahrenheittoString();




  Serial.print(" From Convert Routine Temp F: ");
  Serial.println(xtemp); // Converts tempC to Fahrenheit  

  int xtemp2 = xtemp  * 100;
  int xtempWhole = xtemp2 / 100;
  int xtempDecimal = xtemp2 - (xtempWhole * 100);
  Serial.print(" AGAIN.....From Convert Routine Temp F: ");
  Serial.print(xtempWhole); // Converts tempC to Fahrenheit  
  Serial.print(".");
  Serial.println(xtempDecimal);
  String tempFStringW = itoa((xtempWhole), buf, 10);  
  String tempFStringD = itoa((xtempDecimal), buf, 10);
  String thisString = tempFStringW + "." + tempFStringD;
  Serial.print(" ONCE AGAIN.....From Convert Routine Temp F: ");
  Serial.println(thisString); // Converts tempC to Fahrenheit  





  Serial.println(thisString);
  int lgth = thisString.length();
  Serial.println(thisString.length());
  Serial.println(lgth);
  Serial.println("start");
  if(buttonState==0){
    Serial.println("SKIPPING!!!");
    // goto SkipSpeaking;
  }
  else {
    for (int i=0; i <= lgth-1; i++){
      int say = (thisString.substring(i,i+1)).toInt();
      Serial.println(thisString.substring(i,i+1)); 
      String isDecPoint=(thisString.substring(i,i+1));
      Serial.print("saying ");
      Serial.print(isDecPoint );
      //if (isDecPoint=="."){
     //   Serial.println("FOUND ONE ...... THAT IS!"); 
     // }
      //Serial.print(" ");
      //Serial.println(say); 
      delay(100);  // needed to prevent audio "pops" at start

      if(isDecPoint=="."){
        Serial.println("FOUND SECOND ONE ...... THAT IS!"); 
        delay(200);
        mp3_play(12);
        delay(200);
      }

      else if (say == 0 ){
        mp3_play(10); //zero
      }
      /*else if(isDecPoint=="."){
       Serial.println("FOUND SECOND ONE ...... THAT IS!"); 
       mp3_play(12);
       } 
       */
      else{
        mp3_play(say);   
      }
      dlayPrint();// delay(1200);
      lcd.setCursor(0,1);
    }
    mp3_play(13);  //degrees
    dlayPrint();
    mp3_play(14);  //fahrenheit
    dlayPrint();//delay (1200);
  }
  //SkipSpeaking:

  Serial.print("Requesting temperatures...");
  sensors.requestTemperatures(); // Send the command to get temperatures
  Serial.println("DONE");

  // Loop through each device, print out temperature data
  for(int i=0;i<numberOfDevices; i++)
  {
    // Search the wire for address
    if(sensors.getAddress(tempDeviceAddress, i))
    {
      // Output the device ID
      Serial.print("Temperature for device: ");
      Serial.println(i,DEC);

      // It responds almost immediately. Let's print out the data
      printTemperature(tempDeviceAddress); // Use a simple function to print out the data
    } 
    //else ghost device! Check your power requirements and cabling
  }

}

// routine to stay here till busy pin goes low once then goes high after speach item completes
void dlayPrint()
{
  int bsyflag=0;
  Serial.println(" ");
  Serial.print("buusypin ");
  for( z=0; z<=300; z++){
    bsy = digitalRead(buusyPin);
    Serial.print(bsy);
    delay(20); 
    if (bsyflag==1 && bsy==1){
      break;
    }
    if(bsy==0){
      bsyflag=1;
    }
  }
  Serial.println(" ");
  Serial.println("done");
}

// function to print a device address
void printAddress(DeviceAddress deviceAddress)
{
  for (uint8_t i = 0; i < 8; i++)
  {
    if (deviceAddress[i] < 16) Serial.print("0");
    Serial.print(deviceAddress[i], HEX);
  }
}

// function to print the temperature for a device
void printTemperature(DeviceAddress deviceAddress)
{
  float tempC = sensors.getTempC(deviceAddress);
  Serial.print("Temp C: ");
  Serial.print(tempC);
  Serial.print(" Temp F: ");
  Serial.println(DallasTemperature::toFahrenheit(tempC)); // Converts tempC to Fahrenheit
  xtemp = DallasTemperature::toFahrenheit(tempC);
  lcd.setCursor (8,0);
  lcd.print(xtemp);
  //delay(2000);
  convertFahrenheittoString();
}


void convertFahrenheittoString()
{
  Serial.print(" From Convert Routine Temp F: ");
  Serial.println(xtemp); // Converts tempC to Fahrenheit  

  int xtemp2 = xtemp  * 100;
  int xtempWhole = xtemp2 / 100;
  int xtempDecimal = xtemp2 - (xtempWhole * 100);
  Serial.print(" AGAIN.....From Convert Routine Temp F: ");
  Serial.print(xtempWhole); // Converts tempC to Fahrenheit  
  Serial.print(".");
  Serial.println(xtempDecimal);
  String tempFStringW = itoa((xtempWhole), buf, 10);  
  String tempFStringD = itoa((xtempDecimal), buf, 10);
  String thisString = tempFStringW + "." + tempFStringD;
  Serial.print(" ONCE AGAIN.....From Convert Routine Temp F: ");
  Serial.println(thisString); // Converts tempC to Fahrenheit  

}


//String thisString = itoa(xtemp, buf, 10);