The SOund MOdule 2 (SOMO-II), from 4D Systems, is a compact audio-sound module designed for all embedded audio-sound applications. The SOMO-II is designed to play MP3 audio files from a micro-SD card or USB 2.0 flash drive with extra components. An on-board 16-bit MCU is specifically designed for hardware audio decoding.
The files can be stored in the root folder of the micro-SD or USB flash drive. It can take up to 99 folders with 255 songs in each. The audio files can be loaded onto the micro-SD card or USB flash drive using a PC or laptop without additional software.

The SOMO-II offers two modes, SERIAL-MODE and KEY-MODE:
SERIAL-MODE has a 2-wire serial UART interface to a microcontroller via the TX and RX pins. A range of audio operations such as play, pause, stop, next, previous and volume control are available to the host micro through serial commands.
KEY-MODE is a stand-alone operation where the host micro is not needed. It is then possible to control the module with just a few push buttons.

Features of the SOMO-II audio-sound module:
Compact 16-pin package
Dimensions: 21 x 20.5 x 11.3 mm
24-bit DAC output
SERIAL-MODE or KEY-MODE
Mono amplified speaker output
Stereo DAC audio output for external amp/headphones
On-board micro-SD adaptor
Supports up to 32GB micro-SD or USB 2.0 flash drive
3.3V to 5V DC voltage range (single supply)