STMicroelectronics AN3997 Audio Playback and Recording Application Note

About this manual

This document details an application for audio playback and recording based on the STM32F4xx microcontroller and the STM32F4-DISCOVERY board. The system supports reading audio data from the internal Flash memory or an external USB key and recording data to the USB key. It utilizes a MEMS microphone with PDM audio software decoding to convert PDM data to PCM data stored on the USB key.

What's inside

• Application overview
• Firmware driver description
• Audio playback application
• Playback from USB key
• Playback from internal Flash
• Audio record application
• How to use the application
• System requirements
• Revision history

Frequently asked questions

What hardware is required to run the audio playback and recording application?

The application is based on an STM32F4xx microcontroller and an STM32F4-DISCOVERY board.

What specific microphone hardware does the recording process use?

The recording process uses ST MP45DT02 MEMS microphone hardware with a PDM audio software decoding Library.

How does the user switch between playback and recording modes?

If the selected media is a USB key, pressing the user button stops the current application and switches to the other one.