The SOMO-II (SOund MOdule 2) is a tiny Audio/Sound module that can play MP3 audio files such as voice and music stored on a microSD memory card or on an externally connected USB 2.0 Flash drive. The module features an on-board 16-bit MCU specifically designed for hardware audio decoding.
The module supports both FAT16 and FAT32 formatted microSD cards and USB Flash drives up to 32GB in size, and features a 24-bit DAC output with support for all MP3 bit rates (11172-3 and ISO13813-3 three-layer audio decoding) with sampling rates from 8kHz to 48kHz.
Files can be stored either in the root folder or subfolders on the microSD card or USB Flash drive. SOMO-II supports up to 100 folders, and each folder can contain up to 255 audio files.
You can use a PC or Laptop to load files to a microSD card or USB Flash drive, then insert the card or connect the drive to the SOMO-II. No external software is required.
This compact 16-pin drop-in module takes up very minimal board space and is ideal for any application that requires embedded audio.
The SOMO-II features an on-board mono amplifier capable of driving a 4Ω, 3W speaker directly. It also features stereo DAC output for connecting to headphones or to an external amplifier.
Slave or Standalone Operation The SOMO-II module offers two modes of operation: SERIAL-MODE and KEY-MODE.
SERIAL-MODE provides a simple 2-wire Serial UART interface to any microcontroller via its TX and RX pins. Audio operations such as PLAY, PAUSE, STOP, NEXT, PREVIOUS and VOLUME control functions are all available to the host micro via simple serial commands, along with many more. SERIAL-MODE features a CRC check.
KEY-MODE provides a standalone operation in which a host microcontroller is not required. You need only to connect as few as two buttons to control the module. An array of buttons can be added via various resistor values to get full control of the module without having to use an external processor. With as few as two pushbuttons, a battery (3.3V to 5V) and a speaker, you can create an extremely compact and low-component-count MP3 player system.
In short, the SOMO-II offers a very flexible, compact and low-cost embedded audio solution for many applications.
Tiny Embedded Sound Module Features
- Low-cost module for all embedded Audio-Sound applications
- Supports all MP3 bit rates 11172-3 & ISO1381303 with sample rates from 8kHz to 48kHz
- 24-bit DAC output, dynamic range supports 90dB; SNR supports 85dB
- SERIAL MODE: Supports a 2-Wire 3.3V TTL UART interface to any microcontroller
- KEY-MODE: Supports a simple stand-alone operation without a host micro
- Mono amplified speaker output capable of driving 4Ω speaker at 3W (5V supply)
- Stereo DAC audio output to use with an external amplifier or headphones
- On-board microSD memory card adapter for storing of audio, voice and music files
- Supports up to 32GB microSD cards, FAT16 or FAT32 format
- Supports up to 32GB USB 2.0 Flash drive (if you connect a USB socket), FAT16 or FAT32
- Compact size: 21.0mm long × 20.5mm wide × 11.3mm high
- Weight: about 2g
- 3.3V to 5.0V DC voltage range (single supply)
- RoHS and CE compliant
Download the SOMO-II Data Sheet
Use with a 4D Systems Intelligent Display Download Application Note AN-00071 for a demonstration (with example code) of how to use SOMO-II in the ViSi environment of the 4D Workshop IDE with an intelligent display module such as: