This is a code example that demonstrates how to connect to multiple Wi-Fi networks and set up a hotspot using an ESP8266 microcontroller. The code uses the ESP8266WiFi and ESP8266WiFiMulti libraries to add two Wi-Fi networks and attempt to connect to them. If both networks are unavailable, the code creates a hotspot with the SSID "nodemcu-hotspo…

ESP8266_Multiple_WiFi_With_Backup_Hotspot.c

/*
 * MultipleWiFiWithBackupHotspot.c
 *
 * Connect to Multiple Wi-Fi Networks and Set Up a Hotspot as a Backup with ESP8266
 *
 * This is a code example that demonstrates how to connect to multiple Wi-Fi networks and set up a hotspot using an ESP8266 microcontroller.
 * The code uses the ESP8266WiFi and ESP8266WiFiMulti libraries to add two Wi-Fi networks and attempt to connect to them. 
 * If both networks are unavailable, the code creates a hotspot with the SSID "nodemcu-hotspot" and password "password". 
 * The code is useful for applications where the ESP8266 needs to connect to multiple Wi-Fi networks and have a backup hotspot as a fail-safe mechanism.
 *
 * Author: Karthik V
 */


#include <ESP8266WiFi.h> // Include the ESP8266 WiFi library
#include <ESP8266WiFiMulti.h> // Include the ESP8266 WiFiMulti library

const char* ssid1 = "your_wifi_ssid1"; // Replace "your_wifi_ssid1" with your first Wi-Fi network SSID
const char* password1 = "your_wifi_password1"; // Replace "your_wifi_password1" with your first Wi-Fi network password
const char* ssid2 = "your_wifi_ssid2"; // Replace "your_wifi_ssid2" with your second Wi-Fi network SSID
const char* password2 = "your_wifi_password2"; // Replace "your_wifi_password2" with your second Wi-Fi network password

ESP8266WiFiMulti wifiMulti; // Create an instance of the ESP8266WiFiMulti class

void setup() {
  Serial.begin(9600); // Start the serial communication

  wifiMulti.addAP(ssid1, password1); // Add the first Wi-Fi network to the ESP8266WiFiMulti instance
  wifiMulti.addAP(ssid2, password2); // Add the second Wi-Fi network to the ESP8266WiFiMulti instance
  
  Serial.println("");
  Serial.print("Connecting to Wi-Fi");

  int attempts = 0; // Initialize the number of connection attempts

  while (wifiMulti.run() != WL_CONNECTED && attempts < 10) { // Wait for connection or timeout after 10 attempts
    Serial.print("."); // Print a dot to the serial monitor
    delay(1000);
    attempts++;
  }

  if (wifiMulti.run() == WL_CONNECTED) { // Check if the ESP8266 is connected to Wi-Fi
    Serial.println("");
    Serial.println("Connected to Wi-Fi");
  } else {
    Serial.println(""); 
    Serial.println("Timed out, creating hotspot...");
    WiFi.softAP("nodemcu-hotspot", "password"); // Create a hotspot with the SSID "nodemcu-hotspot" and password "password"
  }
}

void loop() {
  // Your code goes here
}