ESP32 Useful Wi-Fi Library Functions (Arduino IDE) | Random Nerd Tutorials (2024)

This article is a compilation of useful Wi-Fi functions for the ESP32. We’ll cover the following topics: scan Wi-Fi networks, connect to a Wi-Fi network, get Wi-Fi connection strength, check connection status, reconnect to the network after a connection is lost, Wi-Fi status, Wi-Fi modes, get the ESP32 IP address, set a fixed IP address and more.

This is not a novelty. There are plenty of examples of how to handle Wi-Fi with the ESP32. However, we thought it would be useful to compile some of the most used and practical Wi-Fi functions for the ESP32.

Table of Contents

Here’s a list of what will be covered in this tutorial (you can click on the links to go to the corresponding section):

• Wi-Fi Modes: station, access point and both (station + access point);
• Scan Wi-Fi networks;
• Connect to a Wi-Fi network;
• Get Wi-Fi connection status;
• Check Wi-Fi connection strength;
• Get ESP32 IP address;
• Set an ESP32 Static IP address;
• Disconnect Wi-Fi;
• Reconnect to Wi-Fi after connection is lost;
• ESP32 Wi-Fi Events;
• Reconnect to Wi-Fi Network After Lost Connection (Wi-Fi Events);
• ESP32 WiFiMulti
• Change ESP32 Hostname.

Including the Wi-Fi Library

The first thing you need to do to use the ESP32 Wi-Fi functionalities is to include the WiFi.h library in your code, as follows:

#include <WiFi.h>

This library is automatically “installed” when you install the ESP32 add-on in your Arduino IDE. If you don’t have the ESP32 installed, you can follow the next tutorial:

• Installing the ESP32 Board in Arduino IDE (Windows, Mac OS X, Linux)

If you prefer to use VS Code + PaltformIO, you just need to start a new project with an ESP32 board to be able to use the WiFi.h library and its functions.

ESP32 Wi-Fi Modes

The ESP32 board can act as Wi-Fi Station, Access Point or both. To set the Wi-Fi mode, use WiFi.mode() and set the desired mode as argument:

Wi-Fi Station

When the ESP32 is set as a Wi-Fi station, it can connect to other networks (like your router). In this scenario, the router assigns a unique IP address to your ESP board. You can communicate with the ESP using other devices (stations) that are also connected to the same network by referring to the ESP unique IP address.

The router is connected to the internet, so we can request information from the internet using the ESP32 board like data from APIs (weather data, for example), publish data to online platforms, use icons and images from the internet or include JavaScript libraries to build web server pages.

Set the ESP32 as a Station and Connect to Wi-Fi Network

Go to “Connect to Wi-Fi Network” to learn how to set the ESP32 as station and connect it to a network.

In some cases, this might not be the best configuration – when you don’t have a network nearby and want you still want to connect to the ESP to control it. In this scenario, you must set your ESP board as an access point.

Access Point

When you set your ESP32 board as an access point, you can be connected using any device with Wi-Fi capabilities without connecting to your router. When you set the ESP32 as an access point, you create its own Wi-Fi network, and nearby Wi-Fi devices (stations) can connect to it, like your smartphone or computer. So, you don’t need to be connected to a router to control it.

This can be also useful if you want to have several ESP32 devices talking to each other without the need for a router.

Because the ESP32 doesn’t connect further to a wired network like your router, it is called soft-AP (soft Access Point). This means that if you try to load libraries or use firmware from the internet, it will not work. It also doesn’t work if you make HTTP requests to services on the internet to publish sensor readings to the cloud or use services on the internet (like sending an email, for example).

Set the ESP32 as an Access Point

To set the ESP32 as an access point, set the Wi-Fi mode to access point:

WiFi.mode(WIFI_AP)

And then, use the softAP() method as follows:

WiFi.softAP(ssid, password);

ssid is the name you want to give to the ESP32 access point, and the password variable is the password for the access point. If you don’t want to set a password, set it to NULL.

There are also other optional parameters you can pass to the softAP() method. Here are all the parameters:

WiFi.softAP(const char* ssid, const char* password, int channel, int ssid_hidden, int max_connection)

• ssid: name for the access point – maximum of 63 characters;
• password: minimum of 8 characters; set to NULL if you want the access point to be open;
• channel: Wi-Fi channel number (1-13)
• ssid_hidden: (0 = broadcast SSID, 1 = hide SSID)
• max_connection: maximum simultaneous connected clients (1-4)

We have a complete tutorial explaining how to set up the ESP32 as an access point:

• How to Set an ESP32 Access Point (AP) for Web Server

Wi-Fi Station + Access Point

The ESP32 can be set as a Wi-Fi station and access point simultaneously. Set its mode to WIFI_AP_STA.

WiFi.mode(WIFI_AP_STA);

Scan Wi-Fi Networks

The ESP32 can scan nearby Wi-Fi networks within its Wi-Fi range. In your Arduino IDE, go to File > Examples > WiFi > WiFiScan. This will load a sketch that scans Wi-Fi networks within the range of your ESP32 board.

This can be useful to check if the Wi-Fi network you’re trying to connect is within the range of your board or other applications. Your Wi-Fi project may not often work because it may not be able to connect to your router due to insufficient Wi-Fi strength.

Here’s the example:

/* Example from WiFi > WiFiScan Complete details at https://RandomNerdTutorials.com/esp32-useful-wi-fi-functions-arduino/*/#include "WiFi.h"void setup() { Serial.begin(115200); // Set WiFi to station mode and disconnect from an AP if it was previously connected WiFi.mode(WIFI_STA); WiFi.disconnect(); delay(100); Serial.println("Setup done");}void loop() { Serial.println("scan start"); // WiFi.scanNetworks will return the number of networks found int n = WiFi.scanNetworks(); Serial.println("scan done"); if (n == 0) { Serial.println("no networks found"); } else { Serial.print(n); Serial.println(" networks found"); for (int i = 0; i < n; ++i) { // Print SSID and RSSI for each network found Serial.print(i + 1); Serial.print(": "); Serial.print(WiFi.SSID(i)); Serial.print(" ("); Serial.print(WiFi.RSSI(i)); Serial.print(")"); Serial.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*"); delay(10); } } Serial.println(""); // Wait a bit before scanning again delay(5000);}

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You can upload it to your board and check the available networks as well as the RSSI (received signal strength indicator).

WiFi.scanNetworks() returns the number of networks found.

int n = WiFi.scanNetworks();

After the scanning, you can access the parameters about each network.

WiFi.SSID() prints the SSID for a specific network:

Serial.print(WiFi.SSID(i));

WiFi.RSSI() returns the RSSI of that network. RSSI stands for Received Signal Strength Indicator. It is an estimated measure of power level that an RF client device is receiving from an access point or router.

Serial.print(WiFi.RSSI(i));

Finally, WiFi.encryptionType() returns the network encryption type. That specific example puts a * in the case of open networks. However, that function can return one of the following options (not just open networks):

• WIFI_AUTH_OPEN
• WIFI_AUTH_WEP
• WIFI_AUTH_WPA_PSK
• WIFI_AUTH_WPA2_PSK
• WIFI_AUTH_WPA_WPA2_PSK
• WIFI_AUTH_WPA2_ENTERPRISE

Connect to a Wi-Fi Network

To connect the ESP32 to a specific Wi-Fi network, you must know its SSID and password. Additionally, that network must be within the ESP32 Wi-Fi range (to check that, you can use the previous example to scan Wi-Fi networks).

You can use the following function to connect the ESP32 to a Wi-Fi network initWiFi():

void initWiFi() { WiFi.mode(WIFI_STA); WiFi.begin(ssid, password); Serial.print("Connecting to WiFi .."); while (WiFi.status() != WL_CONNECTED) { Serial.print('.'); delay(1000); } Serial.println(WiFi.localIP());}

The ssid and password variables hold the SSID and password of the network you want to connect to.

// Replace with your network credentialsconst char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";

Then, you simply need to call the initWiFi() function in your setup().

How it Works?

Let’s take a quick look on how this function works.

First, set the Wi-Fi mode. If the ESP32 will connected to another network (access point/hotspot) it must be in station mode.

WiFi.mode(WIFI_STA);

Then, use WiFi.begin() to connect to a network. You must pass as arguments the network SSID and its password:

WiFi.begin(ssid, password);

Connecting to a Wi-Fi network can take a while, so we usually add a while loop that keeps checking if the connection was already established by using WiFi.status(). When the connection is successfully established, it returns WL_CONNECTED.

while (WiFi.status() != WL_CONNECTED) {

Get Wi-Fi Connection Status

To get the status of the Wi-Fi connection, you can use WiFi.status(). This returns one of the following values that correspond to the constants on the table:

Get WiFi Connection Strength

To get the WiFi connection strength, you can simply call WiFi.RSSI() after a WiFi connection.

Here’s an example:

/* Complete details at https://RandomNerdTutorials.com/esp32-useful-wi-fi-functions-arduino/*/#include <WiFi.h>// Replace with your network credentials (STATION)const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";void initWiFi() { WiFi.mode(WIFI_STA); WiFi.begin(ssid, password); Serial.print("Connecting to WiFi .."); while (WiFi.status() != WL_CONNECTED) { Serial.print('.'); delay(1000); } Serial.println(WiFi.localIP());}void setup() { Serial.begin(115200); initWiFi(); Serial.print("RRSI: "); Serial.println(WiFi.RSSI());}void loop() { // put your main code here, to run repeatedly:}

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Insert your network credentials and upload the code.

Open the Serial Monitor and press the ESP32 on-board RST button. It will connect to your network and print the RSSI (received signal strength indicator).

See Also

Connect to Wi-Fi networks with the ESP32

A lower absolute value means a strongest Wi-Fi connection.

Get ESP32 IP Address

When the ESP32 is set as a Wi-Fi station, it can connect to other networks (like your router). In this scenario, the router assigns a unique IP address to your ESP32 board. To get your board’s IP address, you need to call WiFi.localIP() after establishing a connection with your network.

Serial.println(WiFi.localIP());

Set a Static ESP32 IP Address

Instead of getting a randomly assigned IP address, you can set an available IP address of your preference to the ESP32 using WiFi.config().

Outside the setup() and loop() functions, define the following variables with your own static IP address and corresponding gateway IP address. By default, the following code assigns the IP address 192.168.1.184 that works in the gateway 192.168.1.1.

// Set your Static IP addressIPAddress local_IP(192, 168, 1, 184);// Set your Gateway IP addressIPAddress gateway(192, 168, 1, 1);IPAddress subnet(255, 255, 0, 0);IPAddress primaryDNS(8, 8, 8, 8); // optionalIPAddress secondaryDNS(8, 8, 4, 4); // optional

Then, in the setup() you need to call the WiFi.config() method to assign the configurations to your ESP32.

// Configures static IP addressif (!WiFi.config(local_IP, gateway, subnet, primaryDNS, secondaryDNS)) { Serial.println("STA Failed to configure");}

The primaryDNS and secondaryDNS parameters are optional and you can remove them.

We recommend reading the following tutorial to learn how to set a static IP address:

• ESP32 Static/Fixed IP Address

Disconnect from Wi-Fi Network

To disconnect from a previously connected Wi-Fi network, use WiFi.disconnect():

WiFi.disconnect()

Reconnect to Wi-Fi Network After Lost Connection

To reconnect to Wi-Fi after a connection is lost, you can use WiFi.reconnect() to try to reconnect to the previously connected access point:

WiFi.reconnect()

Or, you can call WiFi.disconnect() followed by WiFi.begin(ssid,password).

WiFi.disconnect();WiFi.begin(ssid, password);

Alternatively, you can also try to restart the ESP32 with ESP.restart() when the connection is lost.

You can add something like the snippet below to your loop() that checks once in a while if the board is connected.

unsigned long currentMillis = millis();// if WiFi is down, try reconnectingif ((WiFi.status() != WL_CONNECTED) && (currentMillis - previousMillis >=interval)) { Serial.print(millis()); Serial.println("Reconnecting to WiFi..."); WiFi.disconnect(); WiFi.reconnect(); previousMillis = currentMillis;}

Don’t forget to declare the previousMillis and interval variables. The interval corresponds to the period of time between each check in milliseconds (for example 30 seconds):

unsigned long previousMillis = 0;unsigned long interval = 30000;

Here’s a complete example.

/* Rui Santos Complete project details at https://RandomNerdTutorials.com/solved-reconnect-esp32-to-wifi/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files. The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.*/#include <WiFi.h>// Replace with your network credentials (STATION)const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";unsigned long previousMillis = 0;unsigned long interval = 30000;void initWiFi() { WiFi.mode(WIFI_STA); WiFi.begin(ssid, password); Serial.print("Connecting to WiFi .."); while (WiFi.status() != WL_CONNECTED) { Serial.print('.'); delay(1000); } Serial.println(WiFi.localIP());}void setup() { Serial.begin(115200); initWiFi(); Serial.print("RSSI: "); Serial.println(WiFi.RSSI());}void loop() { unsigned long currentMillis = millis(); // if WiFi is down, try reconnecting every CHECK_WIFI_TIME seconds if ((WiFi.status() != WL_CONNECTED) && (currentMillis - previousMillis >=interval)) { Serial.print(millis()); Serial.println("Reconnecting to WiFi..."); WiFi.disconnect(); WiFi.reconnect(); previousMillis = currentMillis; }}

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This example shows how to connect to a network and checks every 30 seconds if it is still connected. If it isn’t, it disconnects and tries to reconnect again.

You can read our guide: [SOLVED] Reconnect ESP32 to Wi-Fi Network After Lost Connection.

Alternatively, you can also use WiFi Events to detect that the connection was lost and call a function to handle what to do when that happens (see the next section).

ESP32 Wi-Fi Events

The ESP32 can handle all the following Wi-Fi events (check the source code):

For a complete example on how to use those events, in your Arduino IDE, go to File > Examples > WiFi > WiFiClientEvents.

/* This sketch shows the WiFi event usage - Example from WiFi > WiFiClientEvents Complete details at https://RandomNerdTutorials.com/esp32-useful-wi-fi-functions-arduino/ *//** WiFi Events0 ARDUINO_EVENT_WIFI_READY < ESP32 WiFi ready1 ARDUINO_EVENT_WIFI_SCAN_DONE < ESP32 finish scanning AP2 ARDUINO_EVENT_WIFI_STA_START < ESP32 station start3 ARDUINO_EVENT_WIFI_STA_STOP < ESP32 station stop4 ARDUINO_EVENT_WIFI_STA_CONNECTED < ESP32 station connected to AP5 ARDUINO_EVENT_WIFI_STA_DISCONNECTED < ESP32 station disconnected from AP6 ARDUINO_EVENT_WIFI_STA_AUTHMODE_CHANGE < the auth mode of AP connected by ESP32 station changed7 ARDUINO_EVENT_WIFI_STA_GOT_IP < ESP32 station got IP from connected AP8 ARDUINO_EVENT_WIFI_STA_LOST_IP < ESP32 station lost IP and the IP is reset to 09 ARDUINO_EVENT_WPS_ER_SUCCESS < ESP32 station wps succeeds in enrollee mode10 ARDUINO_EVENT_WPS_ER_FAILED < ESP32 station wps fails in enrollee mode11 ARDUINO_EVENT_WPS_ER_TIMEOUT < ESP32 station wps timeout in enrollee mode12 ARDUINO_EVENT_WPS_ER_PIN < ESP32 station wps pin code in enrollee mode13 ARDUINO_EVENT_WIFI_AP_START < ESP32 soft-AP start14 ARDUINO_EVENT_WIFI_AP_STOP < ESP32 soft-AP stop15 ARDUINO_EVENT_WIFI_AP_STACONNECTED < a station connected to ESP32 soft-AP16 ARDUINO_EVENT_WIFI_AP_STADISCONNECTED < a station disconnected from ESP32 soft-AP17 ARDUINO_EVENT_WIFI_AP_STAIPASSIGNED < ESP32 soft-AP assign an IP to a connected station18 ARDUINO_EVENT_WIFI_AP_PROBEREQRECVED < Receive probe request packet in soft-AP interface19 ARDUINO_EVENT_WIFI_AP_GOT_IP6 < ESP32 ap interface v6IP addr is preferred19 ARDUINO_EVENT_WIFI_STA_GOT_IP6 < ESP32 station interface v6IP addr is preferred20 ARDUINO_EVENT_ETH_START < ESP32 ethernet start21 ARDUINO_EVENT_ETH_STOP < ESP32 ethernet stop22 ARDUINO_EVENT_ETH_CONNECTED < ESP32 ethernet phy link up23 ARDUINO_EVENT_ETH_DISCONNECTED < ESP32 ethernet phy link down24 ARDUINO_EVENT_ETH_GOT_IP < ESP32 ethernet got IP from connected AP19 ARDUINO_EVENT_ETH_GOT_IP6 < ESP32 ethernet interface v6IP addr is preferred25 ARDUINO_EVENT_MAX*/#include <WiFi.h>const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";void WiFiEvent(WiFiEvent_t event){ Serial.printf("[WiFi-event] event: %d\n", event); switch (event) { case ARDUINO_EVENT_WIFI_READY: Serial.println("WiFi interface ready"); break; case ARDUINO_EVENT_WIFI_SCAN_DONE: Serial.println("Completed scan for access points"); break; case ARDUINO_EVENT_WIFI_STA_START: Serial.println("WiFi client started"); break; case ARDUINO_EVENT_WIFI_STA_STOP: Serial.println("WiFi clients stopped"); break; case ARDUINO_EVENT_WIFI_STA_CONNECTED: Serial.println("Connected to access point"); break; case ARDUINO_EVENT_WIFI_STA_DISCONNECTED: Serial.println("Disconnected from WiFi access point"); break; case ARDUINO_EVENT_WIFI_STA_AUTHMODE_CHANGE: Serial.println("Authentication mode of access point has changed"); break; case ARDUINO_EVENT_WIFI_STA_GOT_IP: Serial.print("Obtained IP address: "); Serial.println(WiFi.localIP()); break; case ARDUINO_EVENT_WIFI_STA_LOST_IP: Serial.println("Lost IP address and IP address is reset to 0"); break; case ARDUINO_EVENT_WPS_ER_SUCCESS: Serial.println("WiFi Protected Setup (WPS): succeeded in enrollee mode"); break; case ARDUINO_EVENT_WPS_ER_FAILED: Serial.println("WiFi Protected Setup (WPS): failed in enrollee mode"); break; case ARDUINO_EVENT_WPS_ER_TIMEOUT: Serial.println("WiFi Protected Setup (WPS): timeout in enrollee mode"); break; case ARDUINO_EVENT_WPS_ER_PIN: Serial.println("WiFi Protected Setup (WPS): pin code in enrollee mode"); break; case ARDUINO_EVENT_WIFI_AP_START: Serial.println("WiFi access point started"); break; case ARDUINO_EVENT_WIFI_AP_STOP: Serial.println("WiFi access point stopped"); break; case ARDUINO_EVENT_WIFI_AP_STACONNECTED: Serial.println("Client connected"); break; case ARDUINO_EVENT_WIFI_AP_STADISCONNECTED: Serial.println("Client disconnected"); break; case ARDUINO_EVENT_WIFI_AP_STAIPASSIGNED: Serial.println("Assigned IP address to client"); break; case ARDUINO_EVENT_WIFI_AP_PROBEREQRECVED: Serial.println("Received probe request"); break; case ARDUINO_EVENT_WIFI_AP_GOT_IP6: Serial.println("AP IPv6 is preferred"); break; case ARDUINO_EVENT_WIFI_STA_GOT_IP6: Serial.println("STA IPv6 is preferred"); break; case ARDUINO_EVENT_ETH_GOT_IP6: Serial.println("Ethernet IPv6 is preferred"); break; case ARDUINO_EVENT_ETH_START: Serial.println("Ethernet started"); break; case ARDUINO_EVENT_ETH_STOP: Serial.println("Ethernet stopped"); break; case ARDUINO_EVENT_ETH_CONNECTED: Serial.println("Ethernet connected"); break; case ARDUINO_EVENT_ETH_DISCONNECTED: Serial.println("Ethernet disconnected"); break; case ARDUINO_EVENT_ETH_GOT_IP: Serial.println("Obtained IP address"); break; default: break; }}void WiFiGotIP(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("WiFi connected"); Serial.println("IP address: "); Serial.println(IPAddress(info.got_ip.ip_info.ip.addr));}void setup(){ Serial.begin(115200); // delete old config WiFi.disconnect(true); delay(1000); // Examples of different ways to register wifi events WiFi.onEvent(WiFiEvent); WiFi.onEvent(WiFiGotIP, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_GOT_IP); WiFiEventId_t eventID = WiFi.onEvent([](WiFiEvent_t event, WiFiEventInfo_t info){ Serial.print("WiFi lost connection. Reason: "); Serial.println(info.wifi_sta_disconnected.reason); }, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_DISCONNECTED); // Remove WiFi event Serial.print("WiFi Event ID: "); Serial.println(eventID); // WiFi.removeEvent(eventID); WiFi.begin(ssid, password); Serial.println(); Serial.println(); Serial.println("Wait for WiFi... ");}void loop(){ delay(1000);}

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With Wi-Fi Events, you don’t need to be constantly checking the Wi-Fi state. When a certain event happens, it automatically calls the corresponding handling function.

Reconnect to Wi-Fi Network After Lost Connection (Wi-Fi Events)

Wi-Fi events can be useful to detect that a connection was lost and try to reconnect right after (use the SYSTEM_EVENT_AP_STADISCONNECTED event). Here’s a sample code:

/* Rui Santos Complete project details at https://RandomNerdTutorials.com/solved-reconnect-esp32-to-wifi/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files. The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.*/#include <WiFi.h> const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";void WiFiStationConnected(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("Connected to AP successfully!");}void WiFiGotIP(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("WiFi connected"); Serial.println("IP address: "); Serial.println(WiFi.localIP());}void WiFiStationDisconnected(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("Disconnected from WiFi access point"); Serial.print("WiFi lost connection. Reason: "); Serial.println(info.wifi_sta_disconnected.reason); Serial.println("Trying to Reconnect"); WiFi.begin(ssid, password);}void setup(){ Serial.begin(115200); // delete old config WiFi.disconnect(true); delay(1000); WiFi.onEvent(WiFiStationConnected, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_CONNECTED); WiFi.onEvent(WiFiGotIP, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_GOT_IP); WiFi.onEvent(WiFiStationDisconnected, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_DISCONNECTED); /* Remove WiFi event Serial.print("WiFi Event ID: "); Serial.println(eventID); WiFi.removeEvent(eventID);*/ WiFi.begin(ssid, password); Serial.println(); Serial.println(); Serial.println("Wait for WiFi... ");}void loop(){ delay(1000);}

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How it Works?

In this example we’ve added three Wi-Fi events: when the ESP32 connects, when it gets an IP address, and when it disconnects: ARDUINO_EVENT_WIFI_STA_CONNECTED, ARDUINO_EVENT_WIFI_STA_GOT_IP, ARDUINO_EVENT_WIFI_STA_DISCONNECTED.

When the ESP32 station connects to the access point (ARDUINO_EVENT_WIFI_STA_CONNECTED event), the WiFiStationConnected() function will be called:

 WiFi.onEvent(WiFiStationConnected, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_CONNECTED);

The WiFiStationConnected() function simply prints that the ESP32 connected to an access point (for example, your router) successfully. However, you can modify the function to do any other task (like light up an LED to indicate that it is successfully connected to the network).

void WiFiStationConnected(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("Connected to AP successfully!");}

When the ESP32 gets its IP address, the WiFiGotIP() function runs.

 WiFi.onEvent(WiFiGotIP, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_GOT_IP);

That function simply prints the IP address on the Serial Monitor.

void WiFiGotIP(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("WiFi connected"); Serial.println("IP address: "); Serial.println(WiFi.localIP());}

When the ESP32 loses the connection with the access point (ARDUINO_EVENT_WIFI_STA_DISCONNECTED), the WiFiStationDisconnected() function is called.

 WiFi.onEvent(WiFiStationDisconnected, WiFiEvent_t::ARDUINO_EVENT_WIFI_STA_DISCONNECTED);

That function prints a message indicating that the connection was lost and tries to reconnect:

void WiFiStationDisconnected(WiFiEvent_t event, WiFiEventInfo_t info){ Serial.println("Disconnected from WiFi access point"); Serial.print("WiFi lost connection. Reason: "); Serial.println(info.wifi_sta_disconnected.reason); Serial.println("Trying to Reconnect"); WiFi.begin(ssid, password);}

ESP32 WiFiMulti

The ESP32 WiFiMulti allows you to register multiple networks (SSID/password combinations). The ESP32 will connect to the Wi-Fi network with the strongest signal (RSSI). If the connection is lost, it will connect to the next network on the list. This requires that you include the WiFiMulti.h library (you don’t need to install it, it comes by default with the ESP32 package).

To learn how to use WiFiMulti, read the following tutorial:

• ESP32 WiFiMulti: Connect to the Strongest Wi-Fi Network (from a list of networks)

Change ESP32 Hostname

To set a custom hostname for your board, call WiFi.setHostname(YOUR_NEW_HOSTNAME); before WiFi.begin();

The default ESP32 hostname is espressif.

There is a method provided by the WiFi.h library that allows you to set a custom hostname.

First, start by defining your new hostname. For example:

String hostname = "ESP32 Node Temperature";

Then, call the WiFi.setHostname() function before calling WiFi.begin(). You also need to call WiFi.config() as shown below:

WiFi.config(INADDR_NONE, INADDR_NONE, INADDR_NONE, INADDR_NONE);WiFi.setHostname(hostname.c_str()); //define hostname

You can copy the complete example below:

/* Rui Santos Complete project details at https://RandomNerdTutorials.com/esp32-set-custom-hostname-arduino/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files. The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.*/#include <WiFi.h>// Replace with your network credentials (STATION)const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";String hostname = "ESP32 Node Temperature";void initWiFi() { WiFi.mode(WIFI_STA); WiFi.config(INADDR_NONE, INADDR_NONE, INADDR_NONE, INADDR_NONE); WiFi.setHostname(hostname.c_str()); //define hostname //wifi_station_set_hostname( hostname.c_str() ); WiFi.begin(ssid, password); Serial.print("Connecting to WiFi .."); while (WiFi.status() != WL_CONNECTED) { Serial.print('.'); delay(1000); } Serial.println(WiFi.localIP());}void setup() { Serial.begin(115200); initWiFi(); Serial.print("RRSI: "); Serial.println(WiFi.RSSI());}void loop() { // put your main code here, to run repeatedly:}

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You can use this previous snippet of code in your projects to set a custom hostname for the ESP32.

Important: you may need to restart your router for the changes to take effect.

After this, if you go to your router settings, you’ll see the ESP32 with the custom hostname.

Wrapping Up

This article was a compilation of some of the most used and useful ESP32 Wi-Fi functions. Although there are plenty of examples of using the ESP32 Wi-Fi capabilities, there is little documentation explaining how to use the Wi-Fi functions with the ESP32 using Arduino IDE. So, we’ve decided to put together this guide to make it easier to use ESP32 Wi-Fi-related functions in your projects.

If you have other suggestions, you can share them in the comments section.

We hope you’ve found this tutorial useful.

Learn more about the ESP32 with our resources:

• Learn ESP32 with Arduino IDE
• Build Web Servers with ESP32 and ESP8266
• More ESP32 Projects and Tutorials…