MP3 Click

How does it work?

MP3 Click is based on the VS1053, an Ogg Vorbis, MP3, AAC, WMA, FLAC, and MIDI audio codec chip from VLSI Solution. It is a versatile MP3 decoder/encoder chip that belongs to VLSI Solution's extensive audio processor family and can decode even newer AAC files. It can decode MPEG 1 and MPEG 2 audio layer III (CBR+VBR+ABR) as parts of the MP3 format, MP1, and MP2, MPEG 4, WAV, General MIDI, and FLAC lossless audio with software plugins up to 24bits and 48KHz. The stereo earphone driver can drive a 30Ω load and has zero-cross detection for smooth volume change. The streaming support for MP3 and WAV, EarSpeaker spatial processing, bass, and treble controls are also included.

The VS1053 can encode three different formats from a microphone connector in mono or stereo. Those formats are lossless 16-bit PCM, IMA ADPSM, and a highly compressed, high-quality Ogg Vorbis with a software plugin. Users can easily implement microcontroller software to read MP3 files chunk by chunk and send them the same way to the host MCU. The MP3 Click receives its input bitstream through a serial input bus which it listens to as a system peripheral. The input stream is decoded and passed through a digital volume control to an 18-bit oversampling, multi-bit, sigma-delta DAC. The decoding is controlled via a serial control bus. In addition to the basic decoding, adding application-specific features, like DSP effects, to the user RAM is possible.

The MP3 Click uses an SPI serial interface to communicate with the host MCU. The SPI is used for both chip's serial data interface (SDI) and serial control interface (SCI). The DCS (data chip select) pin forces the serial interface into Standby mode while the chip is activated with a low logic state. In addition, the codec chip can be reset over the RST pin. The data request pin (DREQ) signals if VS1503's 2048-byte FIFO can receive data. It may turn LOW or HIGH anytime, even during a byte transmission. It should be only used to decide whether to send more bytes, while the transmission that has already started doesn't have to be aborted.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on MP3 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Data Request	DREQ	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	DCS	Data Chip Select
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

MP3 Click electrical specifications

Software Support

We provide a library for the MP3 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for MP3 Click driver.

Key functions

• Function writes one byte (command) to MP3

• Function writes one byte ( data ) to MP3

• Function Write 32 bytes ( data ) to MP3

Example Description

This app demonstrates the use of MP3 click for playing .mp3 file from SD.

 void application_task ( void ) 
 { 
     uint32_t file_size = 32778; 
     uint8_t cnt; 
     uint8_t file_pos = 0; 

     log_printf( &logger, "--Play audiorn" ); 

     while( file_size > buff_size ) 
     { 
         for (cnt = 0; cnt < buff_size / 32 ; cnt++) 
         { 
             while( mp3_data_write_32( &mp3, MP3_LAKI + file_pos * 32 ) ); 
             file_pos += 32; 
         } 
         file_size -= buff_size; 
     } 

     for( cnt = 0; cnt < file_size; cnt++ ) 
     { 
         while( mp3_data_write( &mp3, MP3_LAKI[ file_pos ] ) ); 
         file_pos++; 
     } 
     log_printf( &logger, "--Finishrn" ); 
     Delay_ms( 100 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Mp3

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.