IoT (Internet of Things) Project: Google Firebase controlling LED with NodeMCU

In this section, we will control the LED with NodeMCU using Firebase database. In the previous section of this project, Google Firebase using NodeMCU ESP8266 we covered how to create project on Firebase and its configuration with NodeMCU. Before going through this project, we recommend you to read our previous tutorial.

A program to control LED (ON/OFF) using Google Firebase database and NodeMCU

Open your previous code and make slightly changes: add pin connection, set firebase status.

#include <Firebase.h>
#include <FirebaseArduino.h>
#include <FirebaseCloudMessaging.h>
#include <FirebaseError.h>
#include <FirebaseHttpClient.h>
#include <FirebaseObject.h>

//
// Copyright 2015 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

// FirebaseDemo_ESP8266 is a sample that demo the different functions
// of the FirebaseArduino API.

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

// Set these to run example.
#define FIREBASE_HOST "nodemcu-demo-697d8.firebaseio.com"
#define FIREBASE_AUTH "YOUR_FIREBASE_AUTH"
#define WIFI_SSID "NETGEAR64"
#define WIFI_PASSWORD "*JAVATPOINT#"

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

  // connect to wifi.
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("connecting");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println();
  Serial.print("connected: ");
  Serial.println(WiFi.localIP());
  
  Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);
  pinMode(D1,OUTPUT);
  Firebase.set("LED_STATUS",0);
}

int n = 0;

void loop() {
  // set value
  n=Firebase.getInt("LED_STATUS");
  // handle error
  if (n==1) {
      Serial.print("LED is ON");
      digitalWrite(D1,HIGH);
      Serial.println(Firebase.error());  
      return;
       delay(100);
  }
 else{
   Serial.print("LED is OFF");
   digitalWrite(D1,LOW);
 }
  
  // update value
  
}

Compile and upload code to NodeMCU ESP8266. Open the serial monitor and view the status, its current status is 0, and LED has OFF.