AudioInput.h

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// I2S Audio Example for ESP32
// This example demonstrates using I2S audio input to control FastLED strips
// Based on audio levels from microphone or line input
//
// This example uses the extremely popular (as of 2025-September) INMP441 microphone.
// Notes:
//   - Connect L/R to PWR so it's recognized as a right channel microphone.
 
#include <Arduino.h>
#include <FastLED.h>
 
#include "fl/sstream.h"
#include "fl/type_traits.h"
 
#include "fl/audio_input.h"
 
#include "platforms/esp/32/audio/sound_util.h"
 
using fl::i16;
 
// I2S Configuration
#define I2S_WS_PIN 7  // Word Select (LRCLK)
#define I2S_SD_PIN 8  // Serial Data (DIN)
#define I2S_CLK_PIN 4 // Serial Clock (BCLK)
#define I2S_CHANNEL fl::Right
 
fl::AudioConfig config = fl::AudioConfig::CreateInmp441(I2S_WS_PIN, I2S_SD_PIN, I2S_CLK_PIN, I2S_CHANNEL);
fl::shared_ptr<fl::IAudioInput> audioSource;
 
void setup() {
    Serial.begin(115200);
 
    Serial.println("I2S Audio FastLED Example");
    Serial.println("Waiting 5000ms for audio device to stdout initialization...");
    delay(5000);
 
    // Initialize I2S Audio
    fl::string errorMsg;
    audioSource = fl::IAudioInput::create(config, &errorMsg);
 
    if (!audioSource) {
        Serial.print("Failed to create audio source: ");
        Serial.println(errorMsg.c_str());
        return;
    }
 
 
    // Start audio capture
    Serial.println("Starting audio capture...");
    audioSource->start();
 
    // Check for start errors
    fl::string startErrorMsg;
    if (audioSource->error(&startErrorMsg)) {
        Serial.print("Audio start error: ");
        Serial.println(startErrorMsg.c_str());
        return;
    }
 
    Serial.println("Audio capture started!");
}
 
 
void loop() {
    EVERY_N_MILLIS(1000) { Serial.println("loop active."); }
    // Check if audio source is valid
    if (!audioSource) {
        Serial.println("Audio source is null!");
        delay(1000);
        return;
    }
 
    // Check for audio errors
    fl::string errorMsg;
    if (audioSource->error(&errorMsg)) {
        Serial.print("Audio error: ");
        Serial.println(errorMsg.c_str());
        delay(100);
        return;
    }
 
    // Read audio data
    fl::AudioSample sample = audioSource->read();
 
    if (sample.isValid()) {
        EVERY_N_MILLIS(100) {
            const auto& audioBuffer = sample.pcm();
            const i16* max_sample = fl::max_element(audioBuffer.begin(), audioBuffer.end());
            const i16* min_sample = fl::min_element(audioBuffer.begin(), audioBuffer.end());
            fl::sstream ss;
            ss << "\nRead " << audioBuffer.size() << " samples, timestamp: " << sample.timestamp() << "ms\n";
            ss << "Max sample: " << *max_sample << "\n";
            ss << "Min sample: " << *min_sample << "\n";
            ss << "RMS: " << sample.rms() << "\n";
            ss << "ZCF: " << sample.zcf() << "\n";
            FL_WARN(ss.str());
        }
    }
}