ESP32 Forum

Code: Select all

#include "driver/i2s.h"
#define SAMPLES 128 // make it a power of two for best DMA performance
#define SPEECH_BUFFER_SIZE 40960
uint32_t speech_buffer[SPEECH_BUFFER_SIZE];
int last_position_written = 0;

void i2s_config() {
  // input
  i2s_config_t i2s_in_config = {
mode: (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
    sample_rate: 16000,
bits_per_sample: (i2s_bits_per_sample_t)32,
channel_format: I2S_CHANNEL_FMT_RIGHT_LEFT,
communication_format: (i2s_comm_format_t)(I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB),
intr_alloc_flags: ESP_INTR_FLAG_LEVEL1,
    dma_buf_count: 14,
    dma_buf_len: 64
  };
  i2s_pin_config_t i2s_in_pin_config = {
    bck_io_num: 16,
    ws_io_num: 4,
data_out_num: -1, //Not used
    data_in_num: 17
  };

  pinMode(17, INPUT);
  pinMode(16, OUTPUT);
  pinMode(4, OUTPUT);

  i2s_driver_install((i2s_port_t)0, &i2s_in_config, 0, NULL);
  i2s_set_pin((i2s_port_t)0, &i2s_in_pin_config);
}

void setup()
{
  Serial.begin(115200);
  delay(4000);

  i2s_config();
}

void loop()
{
//get sample from mic
  for (int i = 0; i < SAMPLES; i++) {
    int sample = 0;
    uint32_t sample_val[2] = {0, 0};
    bytes_read += i2s_pop_sample((i2s_port_t)0, (char *)sample_val, portMAX_DELAY);
    samples_for_buffer[i] = (sample_val[0] << 5);
  }
  merge_buffer(samples_for_buffer);
}

void merge_buffer(uint32_t samples_for_buffer[]) {
//if the buffer reach the max size send it to the cloud
....
//else merge buffer
  for (int j = 0; j < SAMPLES; j++) {
    speech_buffer[last_position_written] = samples_for_buffer[j];
    last_position_written++;
  }
}