Description:
The WTV020 module (HCMODU0072) is based on the WTV020SD-20 device and allows for direct playback of audio files stored on a microSD card. The module also has outputs that will either drive an 8ohm speaker connected to the SPK+ and SPK- pins, or drive a single ended amplifier directly from its DAC output via the AUDIO-L pin. There are also several options for controlling playback including interfacing push buttons for play/pause, track forward/backwards and volume up/down. Alternatively the module can be controlled via a two wire serial interface (clock and data) that allows for random track selection and playback control.
Please note: The digital pins are not 5V tolerant. If interfacing to a 5V microcontroller, the datasheet recommends using 470R resistors between the microcontroller and this module. Alternatively a level shifter or potential divider can be used. MP3 format files will need to be converted to AD4 format for playback.
Features:
Supports up to 1GB microSD cards.
Supports 4 Bit ADCPM format files.
Sampling rate from 6KHz to 36KHz for AD4 file format.
Sampling rate from 6KHz to 16KHz for WAV file format.
16 Bit DAC / PWM audio outputs,
Key (push button) mode, MP3 mode and two line serial interface mode.
Working voltage: 2.7 to 3.5V DC. 3.3V recommended.
Quiescent current: 3uA
Pinout:

Standalone push button example:

Two line serial example:

Datasheets:
FAQ:
Why does my audio sound distorted?
It is likely that the volume level in your audio files is too high. You can reduce the level using a feely available program such as Audacity.
I am trying to play a particular audio file but it always stops in the middle of play back. Why is this?
This can also be caused by the audio level being too high.