https://esp32.com/viewtopic.php?f=13&t=6156

main.c

#include "freertos/FreeRTOS.h"
#include "freertos/queue.h"
#include "freertos/task.h"
#include "esp_wifi.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "driver/gpio.h"

static void task1(void *pvParameters);
static void task2(void *pvParameters);

static QueueHandle_t systemEvtQueue;

void app_main()
{
  systemEvtQueue = xQueueCreate(10, sizeof(uint8_t));

  xTaskCreate(&task1, "GUI task", 2048, NULL, 10, NULL);
  xTaskCreate(&task2, "Event task", 2048, NULL, 10, NULL);
}

static void task1(void *pvParameters)
{
   uint8_t event = 0;
   while (1)
   {
      event++;
      xQueueSend(systemEvtQueue, (void *)&event, (TickType_t)0);
      ESP_LOGI(__func__, "Sending event %i", event);

      vTaskDelay(100 / portTICK_PERIOD_MS);
      heap_caps_check_integrity_all(true);
   }
}

static void task2(void *pvParameters)
{
   uint8_t event = 0;
   while (1)
   {
      if (xQueueReceive(systemEvtQueue, (void *)&event, (TickType_t)0))
      {
         ESP_LOGI(__func__, "Received event %i", event);
      }
      vTaskDelay(100 / portTICK_PERIOD_MS);
   }
}