5 sound-reactive ESP32 projects to make this weekend (May 22 - 24)

The ESP32 is one of the best microcontrollers on the market for building low-power sensors. By connecting a microphone (and sometimes a few additional components), the ESP32 can react to sound in some interesting ways.

Here are five projects to try.

Portable party lights

Take the party with you

Probably one of the most entertaining ESP32 projects out there, this Instructables guide for a completely portable party light can transform your next get-together (or just sit in the corner of the room, ready for the next time you spin some tunes).

While the guide uses a Leaflabs Leaf Maple Mini STM32F103RCBT6 (try saying that quickly), the author notes that the ESP32 would make the perfect stand-in as a worthwhile upgrade to the project (and naturally works with the Arduino IDE).

The rest of the project relies on a graphic equalizer, a cheap microphone, an optional servo, an LED driver board, and a compact 5,000mAh battery pack to make the design truly portable (plus some resistors, capacitors, wires, glue, screws, and the rest of it).

Sound event detection in Home Assistant

Identify sounds and act on them

Seeed Studio, manufacturers of some of the most trusted ESP32 development boards on the market, have produced a guide to creating a sound event detection module that works with Home Assistant. It uses the company's XIAO ESP32-S3 development board and the D1 sound event detection module to do this.

Built on the ESPHome framework , the finished module can recognize five "abnormal" sound events. These include a baby's cry, glass breaking, gunshots, smoke and carbon dioxide alarms, and the sound of snoring. These can then be used in Home Assistant to log events or even trigger automations.

Decibee loudness reminder

Give one to your loudest coworker

The Decibee is a tiny decibel meter that you can put anywhere you want a subtle reminder to keep your voice down. This particular project uses the M5Stack ATOM Echo smart speaker dev kit (which features an embedded ESP32-PICO-D4 plus a microphone) in addition to the M5Stack Neo HEX 37 RGB LED board. You'll also need a single four-pin cable and a means of powering the device.

The LEDs stay dark when you're quiet, with the lights fading up through yellow, orange, and eventually red when things get louder. You'll even see additional animations during peaks or sustained stretches of loudness, and a rare "heart" animation appears occasionally when you're quiet to reward you for keeping it down.

The device features a browser-based dashboard to show how many hearts and alerts have been earned. You can also adjust the sensitivity to your liking.

Sound-reactive WLED controller

Turn your LED strips into a disco

WLED allows you to use microcontrollers like the ESP32 to control NeoPixel LEDs and other chipsets. It's perfect for smart home mood lighting, with a whole range of special effects, support for 10 LED outputs per ESP32, over-the-air updates, a browser-based configuration tool, and native support for Home Assistant.

You can take WLED to the next level with Audio Reactive WLED , a means of using WLED controllers to react to sound and music. There are a few rules you'll need to follow, depending on the type of chip you have and the microphone you want to use. I2S microphones are seen as the better option, though you can even wire up a line-in and skip the microphone entirely.

Adding sound reactive capabilities to your existing WLED setups is a nice way to turn calm, controllable LED mood lighting into a dance party in a matter of seconds.

ESPHome sound level meter

Log or trigger sounds with ambient noise levels

ESPHome is a framework for building smart home sensors and other accessories using the ESP32 and similar microcontrollers. If you want a simple sensor that can talk to Home Assistant, logging audio events and even triggering automations, this guide should help.

This project brings Ivan Kostoski's Hackaday.io project into ESPHome. For hardware details, you'll need to follow Ivan's guide and use an ESP32, an I2S digital microphone, breadboard, and optional OLED display. With ESPHome installed on your ESP32, you can then add the project with a single line of code in your config file.

Since the guide was posted, ESPHome has implemented sound_level and i2s_audio capabilities that make it even easier to use a microphone in your ESPHome devices.

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Looking for more things to do with an ESP32? Check our last week's Bluetooth ESP32 projects too .