Audio Player; Figure 19. Audio Player Diagram; Figure 20. Audio Player Interface - ST STM3220G-EVAL User Manual

Demonstration architecture overview
2.8

Audio player

The audio player retrieves the WAV files stored in the "Audio" directory in the connected
USB Flash disk (connected to the USB OTG FS port).

Figure 19. Audio player diagram

The user can Stop/Play/Resume/Go Back/ Forward and Mute the audio sample and can
select the title to be played directly from the playlist.

Figure 20. Audio player interface

The user can use a headset or the embedded speaker to output the audio sample. The
peripheral is detected automatically: when the headset is removed, the speaker is
automatically used. The audio player supports all WAV PCM audio files with the
configuration listed in
Table 4.
Sample rate
Channel number
Audio Data Format
Note: This limitation is due to the audio codec used on the STM3220G-EVAL board which accepts
a fixed Master Clock frequency while the STM32F2xx I2S provides a Master clock at a fixed
rate of 256 x f
when listening to audio files with a sample rate below 32 Hz, and use a headset or speaker
for other audio files.
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Table 4.
Audio file configurations
Parameter
(where f is the audio sampling rate). It is recommended to use the headset
S S
Doc ID 018665 Rev 3
UM1069
Value
8 to 96 kHz
Stereo/Mono
16 bits