This device will enable you to play several MP3 files at the push of a button.
The hearth of the system is a Lilypad MP3 board with an onboard Atmel controller and a MP3 decoder chip
The device has 5 buttons and a dial encoder to select between several sound banks.
This device is (partly) functional, even without programming! The used lilypad board is shipped with default firmware that enables you to play up to 5 MP3 files at the push of a button.
If you upload the new firmware that is included in this instructable, you will be able to play up to 35 MP3 sound.
Theoretically, the number of sounds is somewhat unlimited if you rewrite the firmware.
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Step 1: Step1: Collecting the Parts
Here is what you'll need:
1. LilyPad MP3 board, Available at Sparkfun.com art. DEV-11013 ROHS you van find it at
2. Rotary encoder for this board (COM-10982 ROHS)with a nice knob (COM-10597)
Case Farnell 531856 or use whatever case you see fit.
3. Speaker ( optional, you can use head phone set if you like)
4. LIPO Accu, I used a 880mAH 3,7V 3,3WH. You can use different kinds but you have to refer to the datasheet of the mp3 board because you might have to change a resister to make yours work.
5. on/off switch
6. miniature push buttons. normally open 5 pieces
For re-programming the board you'll need the Arduino GUI software and you'll need a 5V FTDI programmer cable. Sparkfun DEV-09718 ROHS
Also, you'll need the firmware.
Step 2: Step 2: Hardware
The Housing I used was ordered at Farnell. # 531856 and it cost around $7
I printed a draft of my front design and attached it to the case in order to copy the markings of holes e.a. onto the case.
As you can see, a made a long sleeve for the speaker's sound so that you can hear the sound when the case is closed. I attached small pieces of matches with hot glue on top of this sleeve and i covered it up with the soundtastic logo.
The front cover and the logo are plastified to make it last longer.
The power switch and the trigger switches are also glued inside the case.
The pictures show more than i can tell right now.
Step 3: Step 3: Prepair the SD Card
The SD card has to be empty.
1 Format the card using FAT
2. place your MP3 files on the card.
The files have to be named in a specific way.
The file names have to be according to the 8.3 standard.
The first two characters are most important. The first character tells the device what button to use to play the file.
The second character tells the device what sound bank the file belongs to.
example 2ADANS.mp3--> this file will be stored in the first bank(A) under button 1
example 3DSING.mp3 --> this file will be stored in the 4th bank( D) under button 3.
In order for the device to function, the first character has to be: 1,2,3,4 or 5 and the second character has to be A,B,C,D,E,F or G. If the second character is different than this, the sound banks will be chaos!
Step 4: Step 4: Uploading the Firmware
You can change the original file if you want but dont forget to compile it afterwards.
The libary files have to be installed in order for the firmware to compile succesfully
You can upload the firmware using a 5V FTDI programmer cable or using your own ISP programmer.
If you don't change the original firmware that is pre installed on a new MP3BOARD, it will only be able to play 5 files. In that case, the filenames have to start with a number: 1,2,3,4 or 5.
Step 5: Step 5: Testing the Unit
If all went well, You should be able to play sounds:
1. Make sure battery is charged
2. Make sure the power switch is on
3. Make sure the power switch on the PCB is also on!
4. Make sure the MP3 sounds on the SD card have the correct name
5. make sure the right bank is selected, default after power on is the White Bank (A)
Have fun playing your sounds!!