Generic Class

Methods and properties described in this section are specific to ESP8266. They are not covered in Arduino WiFi library documentation. Before they are fully documented please refer to information below.


void  onEvent (WiFiEventCb cb, WiFiEvent_t event=WIFI_EVENT_ANY) __attribute__((deprecated))


WiFiEventHandler  onStationModeConnected (std::function< void(const WiFiEventStationModeConnected &)>)
WiFiEventHandler  onStationModeDisconnected (std::function< void(const WiFiEventStationModeDisconnected &)>)
WiFiEventHandler  onStationModeAuthModeChanged (std::function< void(const WiFiEventStationModeAuthModeChanged &)>)
WiFiEventHandler  onStationModeGotIP (std::function< void(const WiFiEventStationModeGotIP &)>)
WiFiEventHandler  onStationModeDHCPTimeout (std::function< void(void)>)
WiFiEventHandler  onSoftAPModeStationConnected (std::function< void(const WiFiEventSoftAPModeStationConnected &)>)
WiFiEventHandler  onSoftAPModeStationDisconnected (std::function< void(const WiFiEventSoftAPModeStationDisconnected &)>)

It should be noted that when an WiFi interface goes down, all WiFiClients are stopped, and all WiFiServers stop serving. When the interface comes up, it is up to the user to reconnect the relevant WiFiClients and bring the WiFiServers back up. For the WiFi station interface, it is suggested to set a callback for onStationModeDisconnected() that shuts down the user app’s WiFiClients and WiFiServers (resource cleanup), and another callback for onStationModeGotIP() that brings them back up. For the SoftAP interface, when the interface is brought up, any servers should be brought up as well.

A detailed explanation of WiFiEventHandler can be found in the section with examples :arrow_right: dedicated specifically to the Generic Class..

Alternatively, check the example sketch WiFiEvents.ino available inside examples folder of the ESP8266WiFi library.



ESP8266 is able to reconnect to the last used Wi-Fi network or establishes the same Access Point upon power up or reset. By default, these settings are written to specific sectors of flash memory every time they are changed in WiFi.begin(ssid, passphrase) or WiFi.softAP(ssid, passphrase, channel), and when WiFi.disconnect or WiFi.softAPdisconnect is invoked. Frequently calling these functions could cause wear on the flash memory (see issue #1054).

Once WiFi.persistent(false) is called, WiFi.begin, WiFi.disconnect, WiFi.softAP, or WiFi.softAPdisconnect only changes the current in-memory Wi-Fi settings, and does not affect the Wi-Fi settings stored in flash memory.


  • WiFi.mode(m): set mode to WIFI_AP, WIFI_STA, WIFI_AP_STA or WIFI_OFF
  • WiFi.getMode(): return current Wi-Fi mode (one out of four modes above)

WiFi power management, DTIM

bool setSleepMode (WiFiSleepType_t type, int listenInterval=0)


(listenInterval appeared in esp8266-arduino core v2.5.0 using the last V2 revision of nonos-sdk before V3)

Quoting nonos-sdk datasheet:

  • NONE: disable power saving
  • LIGHT or MODEM: TCP timer rate raised from 250ms to 3s

When listenInterval is set to 1..10, in LIGHT or MODEM mode, station wakes up every (DTIM-interval * listenInterval). This saves power but station interface may miss broadcast data.

Otherwise (default value 0), station wakes up at every DTIM-interval (configured in the access-point).

Quoting wikipedia:

A Delivery Traffic Indication Map (DTIM) is a kind of Traffic Indication Map (TIM) which informs the clients about the presence of buffered multicast/broadcast data on the access point. It is generated within the periodic beacon at a frequency specified by the DTIM Interval. Beacons are packets sent by an access point to synchronize a wireless network.

Other Function Calls

int32_t  channel (void)
WiFiSleepType_t  getSleepMode ()
bool  setPhyMode (WiFiPhyMode_t mode)
WiFiPhyMode_t  getPhyMode ()
void  setOutputPower (float dBm)
WiFiMode_t  getMode ()
bool  enableSTA (bool enable)
bool  enableAP (bool enable)
bool  forceSleepBegin (uint32 sleepUs=0)
bool  forceSleepWake ()
int  hostByName (const char *aHostname, IPAddress &aResult)

appeared with SDK pre-V3:
uint8_t getListenInterval ();
bool isSleepLevelMax ();

Documentation for the above functions is not yet prepared.

For code samples please refer to separate section with examples dedicated specifically to the Generic Class.