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Sound Reactive LED Projects

Sound Reactive LED Projects

Turn your LEDs into an audio visualizer that reacts to music in real time.

How It Works

  1. Capture audio via I2S microphone (INMP441, SPH0645) or line-in
  2. Process with FFT (Fast Fourier Transform) on the ESP32
  3. Map frequency bands to LED zones
  4. Display effects — spectrum analyzer, beat detection, gradient visualization

WLED Sound Reactive

The WLED community maintains a sound-reactive fork with built-in audio processing.

Hardware needed:

  • ESP32 (ESP8266 is too slow for FFT)
  • I2S microphone (INMP441 — cheap, good quality)
  • LED strip
  • 5V power supply

Setup:

  1. Flash the sound-reactive WLED fork
  2. Connect INMP441 to ESP32:
    • INMP441 SD → GPIO32
    • INMP441 WS → GPIO25
    • INMP441 SCK → GPIO26
    • INMP441 L/R → GND (for left channel)
    • INMP441 VDD → 3.3V
    • INMP441 GND → GND
  3. Enable audio input in WLED config
  4. Choose sound-reactive effects

Standalone Options

  • PixelBlaze — Built-in microphone, web-based pattern editor
  • LEDFX — Desktop app that sends audio-reactive data to WLED via UDP
  • ESP32 + FastLED — Custom code for maximum control

Full Sound Reactive Guide →