// Include I2S driver
#include <driver/i2s.h>
// Connections to INMP441 I2S microphone
#define I2S_WS 25
#define I2S_SD 33
#define I2S_SCK 32
// Use I2S Processor 0
#define I2S_PORT I2S_NUM_0
// Define input buffer length
#define bufferLen 64
int16_t sBuffer[bufferLen];
void i2s_install() {
 // Set up I2S Processor configuration
 const i2s_config_t i2s_config = {
 .mode = i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX),
 .sample_rate = 44100,
 .bits_per_sample = i2s_bits_per_sample_t(16),
 .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
 .communication_format =
i2s_comm_format_t(I2S_COMM_FORMAT_STAND_I2S),
 .intr_alloc_flags = 0,
 .dma_buf_count = 8,
.dma_buf_len = bufferLen,
 .use_apll = false
 };
 i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);
}
void i2s_setpin() {
 // Set I2S pin configuration
 const i2s_pin_config_t pin_config = {
 .bck_io_num = I2S_SCK,
 .ws_io_num = I2S_WS,
 .data_out_num = -1,
 .data_in_num = I2S_SD
 };
 i2s_set_pin(I2S_PORT, &pin_config);
}
void setup() {
 // Set up Serial Monitor
 Serial.begin(115200);
 Serial.println(" ");
 delay(1000);
 // Set up I2S
 i2s_install();
 i2s_setpin();
 i2s_start(I2S_PORT);
 delay(500);
}
void loop() {
 // False print statements to "lock range" on serial plotter display
 // Change rangelimit value to adjust "sensitivity"
 int rangelimit = 3000;
 Serial.print(rangelimit * -1);
 Serial.print(" ");
Serial.print(rangelimit);
 Serial.print(" ");
 // Get I2S data and place in data buffer
 size_t bytesIn = 0;
 esp_err_t result = i2s_read(I2S_PORT, &sBuffer, bufferLen, &bytesIn,
portMAX_DELAY);
 if (result == ESP_OK)
 {
 // Read I2S data buffer
 int16_t samples_read = bytesIn / 8;
 if (samples_read > 0) {
 float mean = 0;
 for (int16_t i = 0; i < samples_read; ++i) {
 mean += (sBuffer[i]);
 }
 // Average the data reading
 mean /= samples_read;
 // Print to serial plotter
 Serial.println(mean);
 }
 }
}