---

#include <driver/i2s_std.h>

i2s_chan_handle_t rx_chan;

#ifndef LED_BUILTIN
#define LED_BUILTIN 8
#endif

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(115200);

  i2s_chan_config_t chan_cfg =
      I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_AUTO, I2S_ROLE_MASTER);

  i2s_new_channel(&chan_cfg, NULL, &rx_chan);

  i2s_std_config_t cfg = {
    .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(16000),
    .slot_cfg = I2S_STD_MSB_SLOT_DEFAULT_CONFIG(
        I2S_DATA_BIT_WIDTH_32BIT,
        I2S_SLOT_MODE_MONO),
    .gpio_cfg = {
      .mclk = I2S_GPIO_UNUSED,
      .bclk = GPIO_NUM_4,   // SCK
      .ws   = GPIO_NUM_5,   // WS
      .dout = I2S_GPIO_UNUSED,
      .din  = GPIO_NUM_3,   // SD
      .invert_flags = {
        .mclk_inv = false,
        .bclk_inv = false,
        .ws_inv = false,
      }
    }
  };

  i2s_channel_init_std_mode(rx_chan, &cfg);
  i2s_channel_enable(rx_chan);
}

void loop() {
  int32_t sample;
  size_t bytes_read;

  if (i2s_channel_read(rx_chan,
                       &sample,
                       sizeof(sample),
                       &bytes_read,
                       pdMS_TO_TICKS(100)) == ESP_OK) {

    int32_t level = abs(sample >> 8);

    if (level > 5000) {     // порог, возможно придется подобрать
      digitalWrite(LED_BUILTIN, HIGH);
    } else {
      digitalWrite(LED_BUILTIN, LOW);
    }
  }
}