esp-idf/examples/peripherals/dac/dac_continuous/dac_audio/README.md

Supported Targets	ESP32	ESP32-S2

DAC Continuous Audio Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

Overview

This example shows how to play a piece of audio by DAC driver.

How to use the Example

Hardware Required

• A development board with ESP32 or ESP32-S2 SoC
• DAC channel to GPIO mapping: see GPIO Summary (switch the chip target on the documentation page if needed)
• Note that some ESP32-S2 DevKits have an LED on the DAC1 pin, so that channel's output may not go fully low
• An Audio Power Amplifier like NS4150
• A speaker or earphone to play the audio

Configure the Project

The audio table and sample rate are extracted at build time from a WAV file under tools/ and written into a generated header in the build directory. In menuconfig, under Example Configuration:

• WAV file name: file under tools/ (default hi_idf_audio.wav)
• DAC audio table bit width: Please select based on the DAC channel configuration

You can also run the converter by hand to inspect the table:

python tools/generate_audio_file.py --bitwidth 8 -o audio_example_file.h tools/hi_idf_audio.wav

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

(Replace PORT with the name of the serial port to use.)

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

You can see the following logs on the monitor:

I (277) dac_audio: DAC audio example start
I (277) dac_audio: --------------------------------------
I (287) dac_audio: DAC initialized success, DAC DMA is ready
I (297) dac_audio: Audio size 95824 bytes, played at frequency 48000 Hz synchronously
Play count: 1
Play count: 2
...

And meanwhile, you can hear the audio played every 1 second from the speaker or earphone.