I2S ADC DMA Test Example

#include <Arduino.h>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_log.h"
#include "driver/i2s.h"
#include "soc/syscon_reg.h"
#include "driver/adc.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "nvs_flash.h"
#include "sr_gen_sine.h"

#define TAG "adc_i2s"

uint32_t    SAMPLE_RATE = 120E3;
uint32_t    NUM_SAMPLES = 512;
uint32_t    SIG_FREQ = 10E3;

static QueueHandle_t i2s_event_queue;
static EventGroupHandle_t wifi_event_group;
SigGen *SineWave          = nullptr;

void setup(){
 Serial.begin(921600);
    i2s_config_t i2s_config ;
    i2s_config.mode =  i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_ADC_BUILT_IN);
    i2s_config.sample_rate = SAMPLE_RATE;                           // 120 KHz
    i2s_config.dma_buf_len = NUM_SAMPLES;                           // 512
    i2s_config.channel_format = I2S_CHANNEL_FMT_ONLY_RIGHT;         // Should be mono but doesn't seem to be
    i2s_config.bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT;
    i2s_config.use_apll = false,
    i2s_config.communication_format = I2S_COMM_FORMAT_I2S;
    i2s_config.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1;
    i2s_config.dma_buf_count = 2;
    //install and start i2s driver
    i2s_driver_install(I2S_NUM_0, &i2s_config, 1, &i2s_event_queue);
    // Connect ADC to I2S
    i2s_set_adc_mode(ADC_UNIT_1, ADC1_CHANNEL_6);
    //i2s_set_clk(I2S_NUM_0,SAMPLE_RATE,I2S_BITS_PER_SAMPLE_16BIT,I2S_CHANNEL_MONO);    // This doesn't work either

    // Generate test signal
    SineWave                    = new SigGen();
    SineWave->channel           = DAC_CHANNEL_1;
    SineWave->waveform          = wfSINE;
    SineWave->frequency         = SIG_FREQ;
    SineWave->enabled           = true;                           // Start signal generator

    i2s_adc_enable(I2S_NUM_0);                                      // Start ADC
}

void loop(){
    uint16_t i2s_read_buff[NUM_SAMPLES];
        system_event_t evt;
        if (xQueueReceive(i2s_event_queue, &evt, portMAX_DELAY) == pdPASS) {
            if (evt.event_id==2) {
                i2s_read_bytes(I2S_NUM_0, (char*)i2s_read_buff,  NUM_SAMPLES * 2, portMAX_DELAY);
                for (int i=0;i<NUM_SAMPLES;i++){
                Serial.printf("%X, ", i2s_read_buff[i] & 0xFFF);
                }
                Serial.println();
                Serial.println();
                Serial.println();
            }
        }
}