After many tries it worked to connect digital mic and digital out to esp32 using two i2s interfaces.
Microphone circuit is sph0645 and output is max 98357a.
Below is a description of what pins i used and simple code to direct input from mic to output.
Using 4 pins to microphone in: SEL to VIN
22 – dout
25 – bclk
26 – lrcl
Output pins:
18 – bclk
19 – lrc
21 – din
#include <Arduino.h>
#include <driver/i2s.h>
#define I2S_SAMPLE_RATE (44100)
#define I2S_SAMPLE_BITS (16)
#define I2S_NUM_CHANNELS (1)
#define I2S_DMA_BUFFER (2048)
#define I2S_LRCK_PIN (26)
#define I2S_BCLK_PIN (25)
#define I2S_DOUT_PIN (22)
void setup() {
Serial.begin(115200);
i2s_config_t i2s_config = {
.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
.sample_rate = I2S_SAMPLE_RATE,
.bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
.communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_I2S),
.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
.dma_buf_count = 32,
.dma_buf_len = 512,
.use_apll = false
};
i2s_pin_config_t pin_config = {
.bck_io_num = I2S_BCLK_PIN,
.ws_io_num = I2S_LRCK_PIN,
.data_out_num = I2S_PIN_NO_CHANGE,
.data_in_num = I2S_DOUT_PIN
};
i2s_driver_install((i2s_port_t)I2S_NUM_0, &i2s_config, 0, NULL);
i2s_set_pin((i2s_port_t)I2S_NUM_0, &pin_config);
i2s_config_t i2s_config2 = {
.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
.sample_rate = I2S_SAMPLE_RATE,
.bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
.communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_I2S),
.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
.dma_buf_count = 32,
.dma_buf_len = 512,
.use_apll = false
};
i2s_pin_config_t pin_config2 = {
.bck_io_num = 18,
.ws_io_num = 19,
.data_out_num = 21,
.data_in_num = I2S_PIN_NO_CHANGE
};
i2s_driver_install((i2s_port_t)I2S_NUM_1, &i2s_config2, 0, NULL);
i2s_set_pin((i2s_port_t)I2S_NUM_1, &pin_config2);
Serial.println("Mikrofon jest gotowy");
}
void loop() {
// Bufor odczytu I2S
static const int I2S_BUFLEN = 512;
//static int16_t i2s_buf[I2S_BUFLEN];
//size_t bytes_read = 0;
size_t bytes_read;
size_t bytes_w;
uint8_t i2s_read_buffer[512];
// Odczytanie danych z mikrofonu
i2s_read(I2S_NUM_0, &i2s_read_buffer, 512, &bytes_read, portMAX_DELAY);
i2s_write(I2S_NUM_1, &i2s_read_buffer, bytes_read,&bytes_w, portMAX_DELAY);
}
