Microphones & Audio Modules

Audio modules let a project listen, speak, beep or play music.

For listening:

  • The INMP441 is a digital I2S MEMS microphone with clean audio, for voice and sound projects on the ESP32. Its supply is 3.63V maximum, so run it from 3.3V.
  • Simpler sound sensor modules with an electret mic give an analog level for clap switches and sound-reactive lights.

For playback:

  • The DFPlayer Mini plays MP3 files from a microSD card and drives a small speaker through its built-in amplifier, using a few serial commands.
  • The PAM8403 is a small amplifier that drives speakers of a few watts.
  • The classic ESP32 can receive Bluetooth audio (A2DP), which turns any speaker into a Bluetooth speaker. The ESP32-C3 and S3 cannot.

How to choose:

  • Pick an I2S mic for real audio.
  • Pick a sound sensor for loudness triggers.
  • Pick a DFPlayer for stored clips.
  • Pick an amplifier for louder output.

Use buzzers for simple beeps. A passive buzzer can play tones; an active buzzer only beeps.

Frequently asked questions

Which microphone works with an ESP32?

The INMP441 I2S microphone, powered from 3.3V (3.63V maximum).

How do I play MP3 files?

Use a DFPlayer Mini. Put MP3s on a microSD card and send it serial commands.

Can an ESP32 be a Bluetooth speaker?

The classic ESP32 can, using A2DP. The C3 and S3 cannot, because they lack Bluetooth Classic.

Active or passive buzzer?

An active buzzer beeps when powered. A passive buzzer can play tones and melodies.

Guides

Reference pages on soldr.ai

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