#include <WiFi.h>                                 // esp32 library
    #include <Firebase_ESP_Client.h>                       // firebase library

    #define FIREBASE_HOST "https://esp32-led-7f940-default-rtdb.firebaseio.com/"  // the project name address from firebase id
    #define FIREBASE_AUTH "4yc0ijl0qQjnSBiytkw3nSltTmCg88xIOEj6DEbT"                                // the secret key generated from firebase
    #define WIFI_SSID "MAKERSPACE"                                    // input your home or public wifi name
    #define WIFI_PASSWORD "12345678"                                // password of wifi ssid

    String fireString_1 = "";                                          // led status received from firebase
    String fireString_2 = "";
    int ledpin1 = 5;
    int ledpin2 = 6;

    //Define FirebaseESP32 data object
    FirebaseData firebaseData;

    void setup() {
      Serial.begin(115200);
      delay(1000);
      pinMode(ledpin1, OUTPUT);
      pinMode(ledpin2, OUTPUT);
      WiFi.begin(WIFI_SSID, WIFI_PASSWORD);                          // try to connect with wifi

      Serial.print("Connecting to ");
      Serial.print(WIFI_SSID);
      while (WiFi.status() != WL_CONNECTED) {
        Serial.print(".");
        delay(500);
      }

      Serial.println();
      Serial.print("Connected to ");
      Serial.println(WIFI_SSID);
      Serial.print("IP Address is : ");
      Serial.println(WiFi.localIP());                                // print local IP address
      Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);                  // connect to firebase
      Firebase.reconnectWiFi(true);
      Firebase.set(firebaseData, "/LED_STATUS_1", "OFF");              // set initial string of "OFF"
      Firebase.set(firebaseData, "/LED_STATUS_2", "OFF");              // set initial string of "OFF"
    }

    void loop() {

      Firebase.get(firebaseData, "/LED_STATUS_1");                     // get led status input from firebase
      fireString_1 = firebaseData.stringData();                        // change to e.g. intData() or boolData()
      Firebase.get(firebaseData, "/LED_STATUS_2"); 
      fireString_2 = firebaseData.stringData(); 
      Serial.println(fireString);

      if (fireString_1 == "ON") {                    // compare the input of led status received from firebase
        Serial.println("Led Turned ON");
        digitalWrite(ledpin1, HIGH);                // make output led ON
      }

      else if (fireString_1 == "OFF") {              // compare the input of led status received from firebase
        Serial.println("Led Turned OFF");
        digitalWrite(ledpin1, LOW);                 // make output led OFF
      }
      
      if (fireString_2 == "ON") {                    // compare the input of led status received from firebase
        Serial.println("Led Turned ON");
        digitalWrite(ledpin2, HIGH);                // make output led ON
      }

      else if (fireString_2 == "OFF") {              // compare the input of led status received from firebase
        Serial.println("Led Turned OFF");
        digitalWrite(ledpin2, LOW);                 // make output led OFF
      }                                // not strictly necessary

      delay(1000); 
    }