Construction date: June ‎20, ‎2012sunny

Cost: ~130.00 dollars

Time to build: 6 hours

Status: Completed

This is a copy of the RFID bear on Make. I have added a few new features in the code, like a free memory check, a random file player and a sound response. The random file player adds another dimension to the character. If you would like to make you own, it is very easy. This project was made for my wife, because she wanted a talking stuffed animal.  If you are not interested in the behavior of the stuffed animal, it is easily changeable with a few code modifications.  Take a look at the final source code, it may help you in some other projects you are currently working on.


Parts list:
A stuffed animal (any will work as long as its big enough to hold everything)
Ardunio Uno
6-8 cell AA battery holder
Serial Parallax RFID reader
Adafruit Wave Shield
8 ohm speaker
RFID tags
1 gig SD memory card
Sound Sensor

A guide to making one yourself: … ear/1411/1

A updated library for the .wav shield:

Final video link

The code below works with random files named like “1.wav” “2.wav”…. the wav is already part of the file name, so when viewing in Windows it will be “1” “2”… all the way to 200. Though this value it easily changed in the code. For the the stitching in Sunny’s back, I took him to a local seamstress who sewed on Velcro strips, which allowed me to put in all of the electronics. As for power, I’m using rechargeable AA’s to run him at the moment, which seem to be doing well. If you have any questions please ask below. The code includes the required lines for the RFID and they tested well.  The reader I had died on me, so I will try and load a new video up with him scanning some tags.

DSC04006 This is a picture of the back of sunny showing the on/off switch sticking out of the Velcro lined compartment.












Most of the internal electronics out for testing.

A more recent change was that I had a old Spark Fun breakout board for a Mems microphone which allowed me to make Sunny respond to different noise levels 5 at the moment. So if you clap your hands too loud next to his ears he will say “Ouch Sunny’s ears hurt now!” With the link below you can view another more detailed page of Sunny’s beginning.



Updated battery pack. from a six cell pack to a battery longer lasting 8 cell pack.


If you have any questions about the build or the code I would be more then happy to help.






<span style="color: #006600;">// Sunny mark 5 code</span>

#include <FatReader.h>
#include <SdReader.h>
#include <TrueRandom.h>
#include "WaveHC.h"
#include "WaveUtil.h"

SdReader memcard;
FatVolume vol;
FatReader root;
FatReader file;
WaveHC wave;

#define ENABLE 7 // Set the pin number for enabling the RFID reader. The Audio Shield uses pins 2-5.
#define NUMTAGS 22

const int analogPin = 1;
int val = 0;
int val1 = 0;
char code[10];
int bytesread = 0;
long randNumber;
long randNumber1;
void randWavFile ();
char randWav[5] = {".WAV"};
char randWav1[20];

char knowntags[NUMTAGS][11] = {"3501D5C881", "35021C5A56", "35021C7DC1", "840033972F", "35021C710E", "8400339993", "06008EA09C", "030096D389", "030096D371", "35021C99A2", "84003399C3", "35021C8DF6", "35021C92BA", "8400339726", "35021C89FE", "35021C83D2", "35021C779F", "35021C935F", "8400339764"};
char soundfiles[NUMTAGS][9] = {"3501D5C8", "35021C5A", "35021C7D", "84003397", "35021C71", "84003399", "06008EA0", "030096D3", "35021C99", "35021C8D", "35021C92", "35021C89", "35021C83", "35021C77", "35021C93"};
char filename[1][13];

void setup() {
//////// Set up RFID reader to collect tag information /////////////////////
Serial.begin(2400); // RFID reader SOUT pin connected to Serial RX pin at 2400bps
pinMode(ENABLE,OUTPUT); // Set digital pin 7 as OUTPUT to connect it to the RFID /ENABLE pin
digitalWrite(ENABLE, LOW); // Activate the RFID reader

//////// Set the pins to output for driving the Audio Shield
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);

////////// Set up the Audio Shield by initializing the memory card for reading ////////
if (!memcard.init()) {
// If something went wrong sdErrorCheck prints out the error check
putstring_nl("Card init. failed!");

//This will optimize the reading of the memory card -- remove it if it times out

// Find a FAT formatted partition by looking in teh first five slots. Remember your memory card should be FAT16 or FAT32 formatted
uint8_t partition;
for (partition = 0; partition < 5; partition++) {
if (vol.init(memcard, partition))
if (partition == 5)
putstring_nl("No valid FAT partition");
while(1); // This is a point of no return. Format your memory card properly and try again.

// Open the root directory for reading the files
if (!root.openRoot(vol))
putstring_nl("Can't open root directory");
while(1); // Something went wrong here so investigate the file system on your memory card.

// If you got this far then the card is ready to read
putstring_nl("Ready to go");

// If we find an error, check what the error is and show it on the serial terminal
void cardErrorCheck(void)
if(!memcard.errorCode()) return;
putstring("\n\rSD I/O error:");
putstring(", ");
while(1); // Stick here if there is an error


void loop() {
//putstring("Free RAM: "); // This can help with debugging, running out of RAM is bad
//Serial.println(freeRam()); // if this is under 150 bytes it may spell trouble!
int mn = 1024; // mn only decreases
int mx = 0; // mx only increases

// Perform 10000 reads. Update mn and mx for each one.
for (int i = 0; i < 3000; ++i) {
int val1 = analogRead(analogPin);
mn = min(mn, val1);
mx = max(mx, val1);
// Serial.print(mn);
// Serial.print(" M=");
// Serial.print(mx);
//Serial.print(" D=");
// Serial.print(mx-mn);
// Serial.println();

if (mx > 678)
playcomplete ("NOISE1.WAV");
if ((mx >= 637) && (mx <=677))
playcomplete ("NOISE2.WAV");
if ((mx >= 596) && (mx <= 636))
playcomplete ("NOISE3.WAV");
if ((mx >= 555) && (mx <= 595))
playcomplete ("NOISE4.WAV");
if ((mx >= 527) && (mx <= 554))
playcomplete ("NOISE5.WAV");
randNumber1 = random(80);
randNumber = random(1, 150);
sprintf(randWav1, "%1d.wav", randNumber);
delay (50);
if (randNumber1 == 1)
if(Serial.available() > 0) { // if data available from reader
if((val = == 10) { // check for header
bytesread = 0;
while(bytesread<10) { // read 10 digit code
if( Serial.available() > 0) {
val =;
if((val == 10)||(val == 13)) { // if header or stop bytes before the 10 digit reading
break; // stop reading
code[bytesread] = val; // add the digit
bytesread++; // ready to read next digit
if(bytesread == 10) { // if 10 digit read is complete
Serial.print("TAG code is: "); // possibly a good TAG
Serial.println(code); // print the TAG code
Serial.flush(); // Flush the serial buffer before trying to read a new code
bytesread = 0;


void playsound(char codetoplay[]) {
for(int i = 0; i<8; i++) { // Make a filename from the first 8 characters of the RFID tag number
silence(); //shut down anything that is currently playing and close that file


void playfile(char *name) {
if (!, name)) {
putstring_nl("Couldn't open file");
if (!wave.create(file)) {
putstring_nl("Not a valid WAV");

void silence() {
if(wave.isplaying) {

void playcomplete(char *name) {
while (wave.isplaying){

int freeRam(void)
extern int __bss_end;
extern int *__brkval;
int free_memory;
if((int)__brkval == 0) {
free_memory = ((int)&free_memory) - ((int)&__bss_end);
else {
free_memory = ((int)&free_memory) - ((int)__brkval);
return free_memory;

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