ThaiEasyElec MP3 User manual

User Manual
ThaiEasyElec MP3 Embedded Module
Version 1.2

Venus Supply Co., Ltd. Page 1
Revision History
Version
Date
Changes
1.2
4 June 2014
Wording Correction
1.1
16 November2013
Image chaged,
Usage with Arduino added
1.0
3 October2013
Original Version

Venus Supply Co., Ltd. Page 2
User Manual of ThaiEasyElec’s MP3 Embedded Module (ETEE043)
The MP3 Module (ETEE043) was designed to be an easy to use, cost-effective MP3 playback
module. It uses BU94502AKS2 as the MP3 decoder which provides fine quality sound with 8 kHz –
48 kHz sampling rate. The user can use any MCU to control the module using parallel or serial
interface. With MP3 files stored on a SD card, the user can select a sound folder, select a file, start
playback and control play volume using simple serial or parallel commands. The SD card can be
as large as 32 GByte. The module is well suited many applications such as queuing system, voice
mail box, station announcement.

Venus Supply Co., Ltd. Page 3
Features
-Support stereo MP3 files
-2 interface modes: serial and parallel
-Support FAT32 and FAT16 file system
-Accept micro SD Card with SDHC supported (maximum 32 GB)
-Sampling rates: 8 kHz - 48 kHz.
-Accept 5 VDC power supply
-Use 20-pin 2.54mm-pitch header for interface
-Dimension: 35x51 mm
Electrical Characteristic
Parameter
Min.
Typ.
Max.
Unit.
Operating voltage
4
5
9
V
Operating current
-
-
150
mA
Input voltage
3.1
-
5.3
V
Output voltage
3.1
-
-
V
Audio Distortion rate
-
0.005
0.05

Audio Dynamic range
-
90
-
dB
Audio Max output level
0.6
0.75
-
Vrms
35 mm
51 mm
3.5 mm
3.5 mm

Venus Supply Co., Ltd. Page 4
Board Description
No. 15V power indicator
N0. 2MP3 Decoder IC, BU94502AKS2
No. 3Mode Setting (Serial / Parallel) for soldering
No. 4BUSY LED
No. 5 MCU Debug Port
No. 6 MCU, STM8S103
No. 7 Micro-SD Card Socket
No. 8Interface Header, see detail below:
Pin No.
Pin Name
Description
1 - 8
P0 –P7
Data Input
9
VOL-
Volume down
10
VOL+
Volume up
11
RESERVE
-
12
RESERVE
-
13
BUSY
Busy, low active
14
PL
Trigger Input, low active
15
RXD
Serial port receiver input
16
TXD
Serial port transmitter output
17
HPR
Audio output right
18
HPL
Audio output left
19
GND
Ground
20
+5V
5V Power input

Venus Supply Co., Ltd. Page 5
How to use the module
1. Prepare files on SD card
Sound files and folders have to be named sequentially with right format so the module is able
to get to the next file or folder. The file names in each folder must be 001.mp3, 002.mp3 …
199.mp3. So there can be 199 files in a folder. And there can be 15 folders on a SD card with
names: 02, 03 … 15. The root directory is considered as the folder 1.
- File ordering example
From figure above, there are 4 files and the file 017.mp3 is counted as the 3rd file. So the user
has to play it using command 0x03.
Note!!
BUSY Pin: BUSY is driven low on initialization state and when a file is being played. In all other
case, the pin is driven high.
PL Pin: PL is the trigger pin with low-level active. When asserted, the module read data from P0-
P7. It must be asserted when data on P0-P7 is ready.

Venus Supply Co., Ltd. Page 6
- Folder ordering example
From figure above, there are 5 folders including the root directory. The folder 11 is counted as the
4th folder, to get into it, use command 0xF4 (Change to folder 4).
As illustrated, it’s recommended to name all files and folders sequentially.
2. Select the operating mode (Serial / Parallel)
2.1To use Parallel mode, M0 and M1 must be connected to GND as shown below (zero-ohm
resistors are used here):
*** By default, the module is configured in parallel mode ***
2.2To use Serial mode, remove M0 and leave M1 connected to GND. See image below:

Venus Supply Co., Ltd. Page 7
3. Control the module in Parallel mode
The module is controlled by Arduino UNO R3 (EADN014) for example. In parallel mode, 10 signals
are used for control: 8-bit data, PL and BUSY. Optionally, +VOL and –VOL can be connected to
switches for increasing or decreasing the volume directly.
The connections are described below:
MP3 module
Pin
Device
+5V
+5V
Arduino
GND
GND
Arduino
P0–P7
D2-D9
Arduino
BUSY
A4
Arduino
PL
A5
Arduino
VOL+
-
Switch 1
VOL-
-
Switch 2
HP_L
Left
Audio Jack
HP_R
Right
Audio Jack
Data In 8 Bits
BUSY PL
+5V
GND
Switch -Vol
Switch +Vol
HP_L HP_R

Venus Supply Co., Ltd. Page 8
From the circuit above, control signals are P0-P7, PL and BUSY. Whenever that BUSY is “High”, the
module is ready to accept new parallel command. The user can send a command to P0-P7 then send
a “Low” strobe pulse on PL. Commands are listed below:
Command Word
Function
BIN
HEX
DEC
P7
P6
P5
P4
P3
P2
P1
P0
0
0
0
0
0
0
0
1
0x01
001
Play the first file
0
0
0
0
0
0
1
0
0x02
002
Play the second file
…
….
…
…
…
….
….
…
…
…..
….
1
1
0
0
0
1
1
1
0xC7
199
Play the 199th file
1
1
0
0
1
0
0
0
0xC8
200
Set volume level to 0(the lowest level)
1
1
0
0
1
0
0
1
0xC9
201
Set volume level to 1
…
….
…
…
…
….
….
…
…
…..
….
1
1
1
0
0
1
1
1
0xE7
231
Set volume level to 31 (the highest level)
1
1
1
0
1
0
0
0
0xE8
232
Increase volume by 1 level
1
1
1
0
1
0
0
1
0xE9
233
Decrease volume by 1 level
1
1
1
0
1
0
1
1
0xEB
235
Pause playback
1
1
1
0
1
1
0
0
0xEC
236
Resume playback
1
1
1
0
1
1
1
1
0xEF
239
Stop playback
1
1
1
1
0
0
0
1
0xF1
241
Change directory to01 (Root directory)
1
1
1
1
0
0
1
0
0xF2
242
Change directory to02
…
….
…
…
…
….
….
…
…
…..
….
1
1
1
1
1
1
1
1
0xFF
255
Change directory to15

Venus Supply Co., Ltd. Page 9
Example 1In parallel mode, send a command to play 001.mp3.
const int P0 = 2;
const int P1 = 3;
const int P2 = 4;
const int P3 = 5;
const int P4 = 6;
const int P5 = 7;
const int P6 = 8;
const int P7 = 9;
const int BUSY = A4;
const int PL = A5;
void set_port() {
pinMode(P0, OUTPUT);
pinMode(P1, OUTPUT);
pinMode(P2, OUTPUT);
pinMode(P3, OUTPUT);
pinMode(P4, OUTPUT);
pinMode(P5, OUTPUT);
pinMode(P6, OUTPUT);
pinMode(P7, OUTPUT);
pinMode(PL, OUTPUT);
pinMode(BUSY,INPUT);
}
boolean cmd_stop =false;
void setup() {
set_port();
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)){
digitalWrite(P0,HIGH);
digitalWrite(P1,LOW);
digitalWrite(P2,LOW);
digitalWrite(P3,LOW);
digitalWrite(P4,LOW);
digitalWrite(P5,LOW);
digitalWrite(P6,LOW);
digitalWrite(P7,LOW);
delay(100);
digitalWrite(PL, LOW);
delay(100);
digitalWrite(PL, HIGH);
cmd_stop = true;
}
}
1.Pin assignments
2.Pins’ direction assignments
3. Callset_port() to set pins’ direction
4. When BUSY is “High”, set data
pins
to 0x01 to the module and send “Low”
strobe pulse.

Venus Supply Co., Ltd. Page 10
Code description:
Functionset_port () is used to initialized pins to be output or input.
Functionsetup()is used for initialization.
When logic on BUSY pin becomes “High” and cmd_stop is false, a command 0x01 will be sent by
setting 8-bit data to 00000001 then send a “Low” strobe pulse on PL. Then cmd_stop is set to true.
This will command the module to play the first file once.
4. When BUSY is “High”, set data pins to 0x01 to the module
and send “Low” strobe pulse.
void set_port() {
pinMode(P0, OUTPUT);
pinMode(P1, OUTPUT);
pinMode(P2, OUTPUT);
pinMode(P3, OUTPUT);
pinMode(P4, OUTPUT);
pinMode(P5, OUTPUT);
pinMode(P6, OUTPUT);
pinMode(P7, OUTPUT);
pinMode(PL, OUTPUT);
pinMode(BUSY,INPUT);
}
void setup() {
set_port();
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)){
digitalWrite(P0,HIGH);
digitalWrite(P1,LOW);
digitalWrite(P2,LOW);
digitalWrite(P3,LOW);
digitalWrite(P4,LOW);
digitalWrite(P5,LOW);
digitalWrite(P6,LOW);
digitalWrite(P7,LOW);
delay(100);
digitalWrite(PL, LOW);
delay(100);
digitalWrite(PL, HIGH);
cmd_stop = true;
}
}

Venus Supply Co., Ltd. Page 11
Example 2In parallel mode, send a command to play 002.mp3 in folder 03.
const int P0 = 2;
const int P1 = 3;
const int P2 = 4;
const int P3 = 5;
const int P4 = 6;
const int P5 = 7;
const int P6 = 8;
const int P7 = 9;
const int BUSY = A4;
const int PL = A5;
void set_port() {
pinMode(P0, OUTPUT);
pinMode(P1, OUTPUT);
pinMode(P2, OUTPUT);
pinMode(P3, OUTPUT);
pinMode(P4, OUTPUT);
pinMode(P5, OUTPUT);
pinMode(P6, OUTPUT);
pinMode(P7, OUTPUT);
pinMode(PL, OUTPUT);
pinMode(BUSY,INPUT);
}
void send_CMD(unsigned char cmd) {
if( cmd&0x01 ) digitalWrite(P0, HIGH); //Bit 0
else digitalWrite(P0, LOW);
if( cmd&0x02 ) digitalWrite(P1, HIGH); //Bit 1
else digitalWrite(P1, LOW);
if( cmd&0x04 ) digitalWrite(P2, HIGH); //Bit 2
else digitalWrite(P2, LOW);
if( cmd&0x08 ) digitalWrite(P3, HIGH); //Bit 3
else digitalWrite(P3, LOW);
if( cmd&0x10 ) digitalWrite(P4, HIGH); //Bit 4
else digitalWrite(P4, LOW);
if( cmd&0x20 ) digitalWrite(P5, HIGH); //Bit 5
else digitalWrite(P5, LOW);
if( cmd&0x40 ) digitalWrite(P6, HIGH); //Bit 6
else digitalWrite(P6, LOW);
if( cmd&0x80 ) digitalWrite(P7, HIGH); //Bit 7
else digitalWrite(P7, LOW);
delay(100); digitalWrite(PL, LOW);
delay(100); digitalWrite(PL, HIGH);
}
boolean cmd_stop =false ;
void setup() {
set_port();
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
send_CMD(0xF3);
delay(200);
while(digitalRead(BUSY) == HIGH) {
send_CMD(0x02);
cmd_stop=true;
}
}
}
3. Set data pins according to sending command
5. When BUSY is “High”, send 0xF3
and 0x02 to the module. To change
directory to 03 and play file 002.mp3.
1.Pin assignments
2. Pins’direction assignments
4. Callset_port() to set pins’ direction

Venus Supply Co., Ltd. Page 12
Code description:
Functionsend_CMD(unsigned char cmd) wraps the code in the first example into a single function. It
accepts a character named cmd, checks cmd bit-by-bit and set 8-bit data pins according to cmd. Then
it sends a strobe pulse on PL.
When logic on BUSY pin becomes “High” and cmd_stop is false, a command 0xF3 will be sent to
change directory to 03. Then wait until BUSY becomes “High” again and a command 0x02 is sent to
play 002.mp3.
void send_CMD(unsigned char cmd) {
if( cmd&0x01 ) digitalWrite(P0, HIGH); //Bit 0
else digitalWrite(P0, LOW);
if( cmd&0x02 ) digitalWrite(P1, HIGH); //Bit 1
else digitalWrite(P1, LOW);
if( cmd&0x04 ) digitalWrite(P2, HIGH); //Bit 2
else digitalWrite(P2, LOW);
if( cmd&0x08 ) digitalWrite(P3, HIGH); //Bit 3
else digitalWrite(P3, LOW);
if( cmd&0x10 ) digitalWrite(P4, HIGH); //Bit 4
else digitalWrite(P4, LOW);
if( cmd&0x20 ) digitalWrite(P5, HIGH); //Bit 5
else digitalWrite(P5, LOW);
if( cmd&0x40 ) digitalWrite(P6, HIGH); //Bit 6
else digitalWrite(P6, LOW);
if( cmd&0x80 ) digitalWrite(P7, HIGH); //Bit 7
else digitalWrite(P7, LOW);
delay(100); digitalWrite(PL, LOW);
delay(100); digitalWrite(PL, HIGH);
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
send_CMD(0xF3);
delay(200);
while(digitalRead(BUSY) == HIGH) {
send_CMD(0x02);
cmd_stop=true;
}
}
}

Venus Supply Co., Ltd. Page 13
4. Control the module in Serial mode
Circuit below shows how to connect the module to Arduino UNO R3 (EADN014) using 3 signals: TX,
RX and BUSY.
Arduino UNO R3 (EADN014) MP3 
MP3 module
Pin
Device
+5V
+5V
Arduino
GND
GND
Arduino
TX
D4
Arduino
RX
D3
Arduino
BUSY
D5
Arduino
VOL+
-
Switch 1
VOL-
-
Switch 2
HP_L
Left
Audio Jack
HP_R
Right
Audio Jack
TX(D4)>>RX
RX(D3)<<TX
(D5) BUSY
PH_L
PH_R
GND
+5V

Venus Supply Co., Ltd. Page 14
In this example, a software serial is used by setting D3 to be RX and D4 to be TX. The
communication is configured to:
Baud rate: 9600, Data Bit : 8, Stop Bit :1, Parity : None
Commands are exactly the same as used in parallel mode:
Command word
Function
HEX
DEC
0x01
001
Play the first file
0x02
002
Play the second file
…
…..
….
0xC7
199
Play the 199th file
0xC8
200
Set volume level to 0(the lowest level)
0xC9
201
Set volume level to 1
…
…..
….
0xE7
231
Set volume level to 31 (the highest level)
0xE8
232
Increase volume by 1 level
0xE9
233
Decrease volume by 1 level
0xEB
235
Pause playback
0xEC
236
Resume playback
0xEF
239
Stop playback
0xF1
241
Change directory to01 (Root directory)
0xF2
242
Change directory to02
…
…..
….
0xFF
255
Change directory to15

Venus Supply Co., Ltd. Page 15
Example 1In serial mode, send a command to play 001.mp3.
Code description:
A software serial port named mySerial is established by using D3 as RX and D4 asTX.
BUSY (D5) is configured to be an input port. Then the serial port is initialized.
void loop D5 “High” cmd_stop False 
When logic on BUSY pin becomes “High” and cmd_stop is false, a command 0x01 will be sent via
serial port. Then cmd_stop is set to true. This will command the module to play the first file once.
#include <SoftwareSerial.h>
SoftwareSerial mySerial(3, 4); // RX, TX
const int BUSY = 5;
boolean cmd_stop =false;
void setup() {
pinMode(BUSY, INPUT);
mySerial.begin(9600);
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
Serial.write(0x01);
cmd_stop=true;
}
}
#include <SoftwareSerial.h>
SoftwareSerial mySerial(3, 4); // RX, TX
void setup() {
pinMode(BUSY, INPUT);
mySerial.begin(9600);
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
mySerial.write(0x01);
cmd_stop=true;
}
}

Venus Supply Co., Ltd. Page 16
Example 2In serial mode, send a command to play 002.mp3 in folder 03.
Code description:
In loop, whenD5 (BUSY) becomes “High”and cmd_stop is false, a command 0xF3 will be sent via
serial port. This will change directory to 03. Then wait until BUSY becomes “High” again and a
command 0x02 is sent to play 002.mp3.
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
mySerial.write(0xF3);
delay(200);
while(digitalRead(BUSY) == HIGH) {
mySerial.write (0x02);
cmd_stop=true;
}
}
}
#include <SoftwareSerial.h>
SoftwareSerial mySerial(3, 4); // RX, TX
const int BUSY = 5;
boolean cmd_stop =false ;
void setup() {
pinMode(BUSY, INPUT);
mySerial.begin(9600);
}
void loop() {
if ((digitalRead(BUSY) == HIGH) && (cmd_stop == false)) {
mySerial.write(0xF3);
delay(200);
while(digitalRead(BUSY) == HIGH) {
mySerial.write (0x02);
cmd_stop=true;
}
}
}