Code to send sensor readings (LDR) onto Firebase Real-Time Database.

NodeMCU_Firebase_LDR_Realtime_Database.ino

// Code to send sensor readings (LDR) onto Firebase Real-Time Database.

#include <ESP8266WiFi.h>
#include <FirebaseArduino.h>

#define WIFI_SSID "..................................."     // WiFi SSID
#define WIFI_PASSWORD "..................................."     //WiFi Password
#define FIREBASE_HOST "..................................."     // my-realtime-database.firebaseio.com
#define FIREBASE_AUTH "..................................."     // Firebase Authentication Token
#define LIGHT_PIN 0

int lum=0;

void setup() {
  Serial.begin(9600);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Connecting");
  while(WiFi.status() != WL_CONNECTED){
    Serial.print(".");
    delay(250);
  }
  Serial.println();
  Serial.print("Connected, ip: ");
  Serial.println(WiFi.localIP());
  pinMode(LIGHT_PIN, INPUT);
  Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);
}

void loop() {
  lum = analogRead(LIGHT_PIN);
  Serial.println(lum);
  Firebase.pushInt("light", lum);
  if(Firebase.failed()){
    Serial.println("Failed:");
  }
  delay(30000);
}

const int LDR = A0; // Defining LDR PIN 
int input_val = 0;  // Varible to store Input values

void setup() {
   Serial.begin(9600); 
}

void loop() {  
   input_val = analogRead(LDR);      // Reading Input
   Serial.print("LDR value is : " );                        
   Serial.println(input_val);        // Writing input on serial monitor.
   delay(1000);       
}