Adding Notes in WiFi.begin docs (closes #4949)

doc/esp8266wifi/station-class.rst

@@ -62,7 +62,7 @@ By default, ESP will attempt to reconnect to Wi-Fi network whenever it is discon
 begin
 ^^^^^
 
-There are several versions (called *`function overloads <https://en.wikipedia.org/wiki/Function_overloading>`__* in C++) of ``begin`` function. One was presented just above:
+There are several versions (called `function overloads <https://en.wikipedia.org/wiki/Function_overloading>`__ in C++) of ``begin`` function. One was presented just above:
 ``WiFi.begin(ssid, password)``. Overloads provide flexibility in number or type of accepted parameters.
 
 The simplest overload of ``begin`` is as follows:
@@ -71,7 +71,9 @@ The simplest overload of ``begin`` is as follows:
 
     WiFi.begin()
 
-Calling it will instruct module to switch to the station mode and connect to the last used access point basing on configuration saved in flash memory.
+Calling it will enable station mode and connect to the last used access point based on configuration saved in flash memory.
+
+Notes: \* It is possible that calling ``begin`` will result in the module being in STA + softAP mode if the module was previously placed into AP mode. \* If you notice strange behavior with DNS or other network functionality, check which mode your module is in (see ``WiFi.mode()`` in the `Generic Class Documentation <generic-class.rst#mode>`__).
 
 Below is the syntax of another overload of ``begin`` with the all possible parameters:
 
@@ -89,7 +91,7 @@ Disable `DHCP <https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
 
 .. code:: cpp
 
-    WiFi.config(local_ip, gateway, subnet, dns1, dns2) 
+    WiFi.config(local_ip, gateway, subnet, dns1, dns2)
 
 Function will return ``true`` if configuration change is applied successfully. If configuration can not be applied, because e.g. module is not in station or station + soft access point mode, then ``false`` will be returned.
 
@@ -160,7 +162,7 @@ Reconnect the station. This is done by disconnecting from the access point an th
 
 .. code:: cpp
 
-    WiFi.reconnect() 
+    WiFi.reconnect()
 
 Notes: 1. Station should be already connected to an access point. If this is not the case, then function will return ``false`` not performing any action. 2. If ``true`` is returned it means that connection sequence has been successfully started. User should still check for connection status, waiting until ``WL_CONNECTED`` is reported:
 
@@ -180,7 +182,7 @@ Sets currently configured SSID and password to ``null`` values and disconnects t
 
 .. code:: cpp
 
-    WiFi.disconnect(wifioff) 
+    WiFi.disconnect(wifioff)
 
 The ``wifioff`` is an optional ``boolean`` parameter. If set to ``true``, then the station mode will be turned off.
 
@@ -191,7 +193,7 @@ Returns ``true`` if Station is connected to an access point or ``false`` if not.
 
 .. code:: cpp
 
-    WiFi.isConnected() 
+    WiFi.isConnected()
 
 setAutoConnect
 ^^^^^^^^^^^^^^
@@ -200,7 +202,7 @@ Configure module to automatically connect on power on to the last used access po
 
 .. code:: cpp
 
-    WiFi.setAutoConnect(autoConnect) 
+    WiFi.setAutoConnect(autoConnect)
 
 The ``autoConnect`` is an optional parameter. If set to ``false`` then auto connection functionality up will be disabled. If omitted or set to ``true``, then auto connection will be enabled.
 
@@ -222,7 +224,7 @@ Set whether module will attempt to reconnect to an access point in case it is di
 
 .. code:: cpp
 
-    WiFi.setAutoReconnect(autoReconnect)  
+    WiFi.setAutoReconnect(autoReconnect)
 
 If parameter ``autoReconnect`` is set to ``true``, then module will try to reestablish lost connection to the AP. If set to ``false`` then module will stay disconnected.
 
@@ -235,7 +237,7 @@ Wait until module connects to the access point. This function is intended for mo
 
 .. code:: cpp
 
-    WiFi.waitForConnectResult()  
+    WiFi.waitForConnectResult()
 
 Function returns one of the following connection statuses: \* ``WL_CONNECTED`` after successful connection is established \* ``WL_NO_SSID_AVAIL``\ in case configured SSID cannot be reached \* ``WL_CONNECT_FAILED`` if password is incorrect \* ``WL_IDLE_STATUS`` when Wi-Fi is in process of changing between statuses \* ``WL_DISCONNECTED`` if module is not configured in station mode
 
@@ -249,7 +251,7 @@ Get the MAC address of the ESP station's interface.
 
 .. code:: cpp
 
-    WiFi.macAddress(mac) 
+    WiFi.macAddress(mac)
 
 Function should be provided with ``mac`` that is a pointer to memory location (an ``uint8_t`` array the size of 6 elements) to save the mac address. The same pointer value is returned by the function itself.
 
@@ -274,7 +276,7 @@ If you do not feel comfortable with pointers, then there is optional version of
 
 .. code:: cpp
 
-    WiFi.macAddress() 
+    WiFi.macAddress()
 
 *Example code:*
 
@@ -292,7 +294,7 @@ Function used to obtain IP address of ESP station's interface.
 
 .. code:: cpp
 
-    WiFi.localIP() 
+    WiFi.localIP()
 
 The type of returned value is `IPAddress <https://github.com/esp8266/Arduino/blob/master/cores/esp8266/IPAddress.h>`__. There is a couple of methods available to display this type of data. They are presented in examples below that cover description of ``subnetMask``, ``gatewayIP`` and ``dnsIP`` that return the IPAdress as well.
 
@@ -399,7 +401,7 @@ The hostname may be changed using the following function:
 
 .. code:: cpp
 
-    WiFi.hostname(aHostname) 
+    WiFi.hostname(aHostname)
 
 Input parameter ``aHostname`` may be a type of ``char*``, ``const char*`` or ``String``. Maximum length of assigned hostname is 32 characters. Function returns either ``true`` or ``false`` depending on result. For instance, if the limit of 32 characters is exceeded, function will return ``false`` without assigning the new hostname.
 
@@ -427,7 +429,7 @@ Return the status of Wi-Fi connection.
 
     WiFi.status()
 
-Function returns one of the following connection statuses: 
+Function returns one of the following connection statuses:
 
 - ``WL_CONNECTED`` after successful connection is established
 - ``WL_NO_SSID_AVAIL`` in case configured SSID cannot be reached
@@ -531,7 +533,7 @@ Below is similar function, but returning BSSID but as a ``String`` type.
 
 .. code:: cpp
 
-    WiFi.BSSIDstr()  
+    WiFi.BSSIDstr()
 
 *Example code:*
 
@@ -552,7 +554,7 @@ Return the signal strength of Wi-Fi network, that is formally called `Received S
 
 .. code:: cpp
 
-    WiFi.RSSI() 
+    WiFi.RSSI()
 
 Signal strength value is provided in dBm. The type of returned value is ``int32_t``.
 
@@ -615,7 +617,7 @@ Depending on connection result function returns either ``true`` or ``false`` (``
 
 ::
 
-    Wi-Fi mode set to WIFI_STA 
+    Wi-Fi mode set to WIFI_STA
     Begin WPS (press WPS button on your router) ... Success
     .........
     Connected, IP address: 192.168.1.102
@@ -631,7 +633,7 @@ Start smart configuration mode by sniffing for special packets that contain SSID
 
 .. code:: cpp
 
-    beginSmartConfig() 
+    beginSmartConfig()
 
 Query Smart Config status, to decide when stop configuration. Function returns either ``true`` or ``false of``\ boolean\` type.
 
@@ -643,6 +645,6 @@ Stop smart config, free the buffer taken by ``beginSmartConfig()``. Depending on
 
 .. code:: cpp
 
-    stopSmartConfig() 
+    stopSmartConfig()
 
 For additional details regarding Smart Config please refer to `ESP8266 API User Guide <http://bbs.espressif.com/viewtopic.php?f=51&t=1023>`__.