Atom Echo S3R、 I2S MIC で遊ぶ。 (M5Stack用PDMマイクユニット)

//i2s_mic_m5nqnoh2_1

#include <driver/i2s.h>

#define I2S_NUM             I2S_NUM_0           // 0 or 1
#define I2S_SAMPLE_RATE     16000
#define I2S_BUFFER_SIZE     512
#define I2S_PIN_CLK         I2S_PIN_NO_CHANGE
//#define I2S_PIN_WS          33 //
#define I2S_PIN_WS          1 //

#define I2S_PIN_DOUT        I2S_PIN_NO_CHANGE
//#define I2S_PIN_DIN         32 //
#define I2S_PIN_DIN         2 //


int16_t i2s_sambles[I2S_BUFFER_SIZE];
void i2sMicInit() {
  i2s_config_t i2s_config = {
    .mode                 = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_PDM),
    .sample_rate          = I2S_SAMPLE_RATE,
    .bits_per_sample      = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format       = I2S_CHANNEL_FMT_ALL_LEFT,
    .communication_format = I2S_COMM_FORMAT_I2S,
    .intr_alloc_flags     = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count        = 4,
    .dma_buf_len          = 256,
    .use_apll             = false,
    .tx_desc_auto_clear   = false,
    .fixed_mclk           = 0
  };
  i2s_pin_config_t pin_config = {
    .bck_io_num           = I2S_PIN_CLK,
    .ws_io_num            = I2S_PIN_WS,
    .data_out_num         = I2S_PIN_DOUT,
    .data_in_num          = I2S_PIN_DIN,
  };
  i2s_driver_install(I2S_NUM, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM, &pin_config);
}
void setup() {
  Serial.begin(115200);
  delay(1000);

  i2sMicInit();
}

void loop() {
  size_t bytes_read;
  i2s_read(I2S_NUM, (void *)i2s_sambles, sizeof(i2s_sambles), &bytes_read, portMAX_DELAY);


  // Display only the first data
  Serial.printf("20000,%6d,-20000\n", i2s_sambles[0]);

//for(int i=0;i<I2S_BUFFER_SIZE;i++){
//  Serial.printf("20000,%6d,-20000\n", i2s_sambles[i]);
//}

}