esp-idf/examples/wifi/scan/main/scan.c

/* Scan 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.
*/

/*
    This example shows how to scan for available set of APs.
*/
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_wifi.h"
#include "esp_log.h"
#include "esp_event_loop.h"
#include "nvs_flash.h"

#define DEFAULT_SCAN_LIST_SIZE CONFIG_EXAMPLE_SCAN_LIST_SIZE

static const char *TAG = "scan";
static void perform_scan(void);
static bool got_scan_done_event= false;

static esp_err_t event_handler(void *ctx, system_event_t *event)
{
    switch(event->event_id) {
    case SYSTEM_EVENT_SCAN_DONE:
        got_scan_done_event = true;
        break;
    default:
        break;
    }
    return ESP_OK;
}

static void print_auth_mode(int authmode)
{
    switch (authmode) {
    case WIFI_AUTH_OPEN:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_OPEN");
        break;
    case WIFI_AUTH_WEP:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_WEP");
        break;
    case WIFI_AUTH_WPA_PSK:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_WPA_PSK");
        break;
    case WIFI_AUTH_WPA2_PSK:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_WPA2_PSK");
        break;
    case WIFI_AUTH_WPA_WPA2_PSK:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_WPA_WPA2_PSK");
        break;
    case WIFI_AUTH_WPA2_ENTERPRISE:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_WPA2_ENTERPRISE");
        break;
    default:
        ESP_LOGI(TAG, "Authmode \tWIFI_AUTH_UNKNOWN");
        break;
    }
}

static void print_cipher_type(int pairwise_cipher, int group_cipher)
{
    switch (pairwise_cipher) {
    case WIFI_CIPHER_TYPE_NONE:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_NONE");
        break;
    case WIFI_CIPHER_TYPE_WEP40:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_WEP40");
        break;
    case WIFI_CIPHER_TYPE_WEP104:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_WEP104");
        break;
    case WIFI_CIPHER_TYPE_TKIP:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_TKIP");
        break;
    case WIFI_CIPHER_TYPE_CCMP:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_CCMP");
        break;
    case WIFI_CIPHER_TYPE_TKIP_CCMP:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_TKIP_CCMP");
        break;
    default:
        ESP_LOGI(TAG, "Pairwise Cipher \tWIFI_CIPHER_TYPE_UNKNOWN");
        break;
    }

    switch (group_cipher) {
    case WIFI_CIPHER_TYPE_NONE:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_NONE");
        break;
    case WIFI_CIPHER_TYPE_WEP40:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_WEP40");
        break;
    case WIFI_CIPHER_TYPE_WEP104:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_WEP104");
        break;
    case WIFI_CIPHER_TYPE_TKIP:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_TKIP");
        break;
    case WIFI_CIPHER_TYPE_CCMP:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_CCMP");
        break;
    case WIFI_CIPHER_TYPE_TKIP_CCMP:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_TKIP_CCMP");
        break;
    default:
        ESP_LOGI(TAG, "Group Cipher \tWIFI_CIPHER_TYPE_UNKNOWN");
        break;
    }
}

/* Initialise a wifi_ap_record_t, get it populated and display scanned data */
static void perform_scan(void)
{
    uint16_t number = DEFAULT_SCAN_LIST_SIZE;
    wifi_ap_record_t ap_info[DEFAULT_SCAN_LIST_SIZE];
    uint16_t ap_count = 0;
    memset(ap_info, 0, sizeof(ap_info));
    ESP_ERROR_CHECK(esp_wifi_scan_get_ap_records(&number, ap_info));
    ESP_ERROR_CHECK(esp_wifi_scan_get_ap_num(&ap_count));
    ESP_LOGI(TAG, "Total APs scanned = %u", ap_count);
    for (int i = 0; (i < DEFAULT_SCAN_LIST_SIZE) && (i < ap_count); i++) {
        ESP_LOGI(TAG, "SSID \t\t%s", ap_info[i].ssid);
        ESP_LOGI(TAG, "RSSI \t\t%d", ap_info[i].rssi);
        print_auth_mode(ap_info[i].authmode);
        if (ap_info[i].authmode != WIFI_AUTH_WEP) {
            print_cipher_type(ap_info[i].pairwise_cipher, ap_info[i].group_cipher);
        }
        ESP_LOGI(TAG, "Channel \t\t%d\n", ap_info[i].primary);
    }
}

/* Initialize Wi-Fi as sta and start scan */
static void init_wifi(void)
{
    tcpip_adapter_init();
    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));

    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
    ESP_ERROR_CHECK(esp_wifi_start());

    ESP_ERROR_CHECK(esp_wifi_scan_start(NULL, true));

    while (1) {
        if (got_scan_done_event == true) {
            perform_scan();
            got_scan_done_event = false;
            break;
        } else {
            vTaskDelay(100 / portTICK_RATE_MS);
        }
    }
}

void app_main()
{
    // Initialize NVS
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK( ret );

    init_wifi();
}