esp-idf/examples/protocols/websocket/main/websocket_example.c

/* ESP HTTP Client Example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/


#include <stdio.h>
#include "esp_wifi.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "protocol_examples_common.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"


#include "esp_log.h"
#include "esp_websocket_client.h"
#include "esp_event.h"

static const char *TAG = "WEBSOCKET";

#if CONFIG_WEBSOCKET_URI_FROM_STDIN
static void get_string(char *line, size_t size)
{
    int count = 0;
    while (count < size) {
        int c = fgetc(stdin);
        if (c == '\n') {
            line[count] = '\0';
            break;
        } else if (c > 0 && c < 127) {
            line[count] = c;
            ++count;
        }
        vTaskDelay(10 / portTICK_PERIOD_MS);
    }
}

#endif /* CONFIG_WEBSOCKET_URI_FROM_STDIN */

static void websocket_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data)
{
    esp_websocket_event_data_t *data = (esp_websocket_event_data_t *)event_data;
    switch (event_id) {
        case WEBSOCKET_EVENT_CONNECTED:
            ESP_LOGI(TAG, "WEBSOCKET_EVENT_CONNECTED");
            break;
        case WEBSOCKET_EVENT_DISCONNECTED:
            ESP_LOGI(TAG, "WEBSOCKET_EVENT_DISCONNECTED");
            break;
        case WEBSOCKET_EVENT_DATA:
            ESP_LOGI(TAG, "WEBSOCKET_EVENT_DATA");
            ESP_LOGI(TAG, "Received opcode=%d", data->op_code);
            ESP_LOGW(TAG, "Received=%.*s\r\n", data->data_len, (char*)data->data_ptr);
            break;
        case WEBSOCKET_EVENT_ERROR:
            ESP_LOGI(TAG, "WEBSOCKET_EVENT_ERROR");
            break;
    }
}

static void websocket_app_start(void)
{
    esp_websocket_client_config_t websocket_cfg = {};

    #if CONFIG_WEBSOCKET_URI_FROM_STDIN
    char line[128];

    ESP_LOGI(TAG, "Please enter uri of websocket endpoint");
    get_string(line, sizeof(line));

    websocket_cfg.uri = line;
    ESP_LOGI(TAG, "Endpoint uri: %s\n", line);

    #else
    websocket_cfg.uri = CONFIG_WEBSOCKET_URI;

    #endif /* CONFIG_WEBSOCKET_URI_FROM_STDIN */

    ESP_LOGI(TAG, "Connecting to %s...", websocket_cfg.uri);

    esp_websocket_client_handle_t client = esp_websocket_client_init(&websocket_cfg);
    esp_websocket_register_events(client, WEBSOCKET_EVENT_ANY, websocket_event_handler, (void *)client);

    esp_websocket_client_start(client);
    char data[32];
    int i = 0;
    while (i < 10) {
        if (esp_websocket_client_is_connected(client)) {
            int len = sprintf(data, "hello %04d", i++);
            ESP_LOGI(TAG, "Sending %s", data);
            esp_websocket_client_send(client, data, len, portMAX_DELAY);
        }
        vTaskDelay(1000 / portTICK_RATE_MS);
    }
    // Give server some time to respond before closing
    vTaskDelay(3000 / portTICK_RATE_MS);
    esp_websocket_client_stop(client);
    ESP_LOGI(TAG, "Websocket Stopped");
    esp_websocket_client_destroy(client);
}

void app_main(void)
{
    ESP_LOGI(TAG, "[APP] Startup..");
    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
    ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());
    esp_log_level_set("*", ESP_LOG_INFO);
    esp_log_level_set("WEBSOCKET_CLIENT", ESP_LOG_DEBUG);
    esp_log_level_set("TRANS_TCP", ESP_LOG_DEBUG);

    ESP_ERROR_CHECK(nvs_flash_init());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
     * Read "Establishing Wi-Fi or Ethernet Connection" section in
     * examples/protocols/README.md for more information about this function.
     */
    ESP_ERROR_CHECK(example_connect());

    websocket_app_start();
}