*
* @attention 1. This API only impact WIFI_MODE_STA or WIFI_MODE_APSTA mode
* @attention 2. If the ESP32 is connected to an AP, call esp_wifi_disconnect to disconnect.
- *
+ * @attention 3. The scanning triggered by esp_wifi_start_scan() will not be effective until connection between ESP32 and the AP is established.
+ * If ESP32 is scanning and connecting at the same time, ESP32 will abort scanning and return a warning message and error
+ * number ESP_ERR_WIFI_STATE.
+ * If you want to do reconnection after ESP32 received disconnect event, remember to add the maximum retry time, otherwise the called
+ * scan will not work. This is especially true when the AP doesn't exist, and you still try reconnection after ESP32 received disconnect
+ * event with the reason code WIFI_REASON_NO_AP_FOUND.
+ *
* @return
* - ESP_OK: succeed
* - ESP_ERR_WIFI_NOT_INIT: WiFi is not initialized by esp_wifi_init
* - ESP_ERR_WIFI_NOT_INIT: WiFi is not initialized by esp_wifi_init
* - ESP_ERR_WIFI_NOT_STARTED: WiFi was not started by esp_wifi_start
* - ESP_ERR_WIFI_TIMEOUT: blocking scan is timeout
+ * - ESP_ERR_WIFI_STATE: wifi still connecting when invoke esp_wifi_scan_start
* - others: refer to error code in esp_err.h
*/
esp_err_t esp_wifi_scan_start(const wifi_scan_config_t *config, bool block);