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 use the All Channel Scan or Fast Scan to connect
    to a Wi-Fi network.

    In the Fast Scan mode, the scan will stop as soon as the first network matching
    the SSID is found. In this mode, an application can set threshold for the
    authentication mode and the Signal strength. Networks that do not meet the
    threshold requirements will be ignored.

    In the All Channel Scan mode, the scan will end only after all the channels
    are scanned, and connection will start with the best network. The networks
    can be sorted based on Authentication Mode or Signal Strength. The priority
    for the Authentication mode is:  WPA2 > WPA > WEP > Open
*/
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_wifi.h"
#include "esp_log.h"
#include "esp_event.h"
#include "nvs_flash.h"

#define DEFAULT_SCAN_LIST_SIZE CONFIG_EXAMPLE_SCAN_LIST_SIZE

static const char *TAG = "scan";

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;
    }
}

/* Initialize Wi-Fi as sta and set scan method */
static void wifi_scan(void)
{
    tcpip_adapter_init();
    ESP_ERROR_CHECK(esp_event_loop_create_default());

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

    uint16_t number = DEFAULT_SCAN_LIST_SIZE;
    wifi_ap_record_t ap_info[DEFAULT_SCAN_LIST_SIZE];
    memset(ap_info, 0, sizeof(ap_info));

    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));
    ESP_ERROR_CHECK(esp_wifi_scan_get_ap_records(&number, ap_info));

    for (int i = 0; i < DEFAULT_SCAN_LIST_SIZE; 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);
    }

}

void app_main(void)
{
    // 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 );

    wifi_scan();
}