![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/ESP8266-Getting-Started-Firebase-Realtime-Database.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nUpdated 21 April 2025<\/em><\/p>\n\n\n\n In a later tutorial, you\u2019ll learn how to create a Firebase web app that you can access from anywhere to monitor and control your ESP8266 using firebase\u2019s realtime database.<\/p>\n\n\n\n We have a similar tutorial for the ESP32 board: Getting Started with Firebase (Realtime Database)<\/a><\/p>\n\n\n\n Firebase is Google\u2019s mobile application development platform that helps you build, improve, and grow your app. It has many services used to manage data from any android, IOS, or web application.<\/p>\n\n\n\n The following paragraph clearly explains the advantages of using Firebase:<\/p>\n\n\n\n “Firebase is a toolset to \u201cbuild, improve, and grow your app\u201d, and the tools it gives you cover a large portion of the services that developers would normally have to build themselves<\/em> but don\u2019t really want to build because they\u2019d rather be focusing on the app experience itself. This includes things like analytics, authentication, databases, configuration, file storage, push messaging, and the list goes on<\/em>. The services are hosted in the cloud and scale with little to no effort on the part of the developer<\/em>.”<\/p>\n\n\n\n This paragraph was taken from this article<\/a>, and we recommend that you read it if you want to better understand what Firebase is and what it allows you to do.<\/p>\n\n\n\n You can use the ESP8266 to connect and interact with your Firebase project, and you can create applications to control the ESP8266 via Firebase from anywhere in the world.<\/p>\n\n\n\n In this tutorial, we\u2019ll create a Firebase project with a Realtime Database and use the ESP8266 to store and retrieve data. Once connected to the internet, the ESP8266 can access the database from anywhere in the world.<\/p>\n\n\n You can have two ESP8266 boards in different networks, with one board storing data and the other board reading the most recent data, for example.<\/p>\n\n\n In a later tutorial, we’ll create a web app using Firebase that will control the ESP8266 to display sensor readings or control outputs from anywhere in the world.<\/p>\n\n\n\n In this tutorial, you’ll learn how to create a Firebase project with a realtime database and store and read data from the database using the ESP8266.<\/p>\n\n\n\n To follow this project, first, you need to set up a Firebase project and create a realtime database for that project. Then, you’ll program the ESP8266 to store and read data from the database. This tutorial is divided into three sections.<\/p>\n\n\n\n Let’s get started!<\/p>\n\n\n\n Follow the next instructions to create a new project on Firebase.<\/p>\n\n\n\n You need to set authentication methods for your app. <\/p>\n\n\n\n “Most apps need to know the identity of a user. In other words, it takes care of logging in and identifying the users (in this case, the ESP8266). Knowing a user’s identity allows an app to securely save user data in the cloud …” To learn more about the authentication methods, you can read the documentation<\/a>.<\/p>\n\n\n\n Next, you need to create a Realtime Database for your project. Follow the next steps to create the database.<\/p>\n\n\n\n The Realtime Database is all set. Now, you also need to get your project API key.<\/p>\n\n\n\n Now, you have everything ready to interface the ESP8266 with the database.<\/p>\n\n\n\n Now that the Firebase Realtime Database is created, you’ll learn how to interface the ESP8266 with the database.<\/p>\n\n\n\n To program the ESP8266, you can use Arduino IDE<\/a>, VS Code with the PlatformIO extension<\/a>, or other suitable software.<\/p>\n\n\n\n Note: <\/strong> For Firebase projects, we recommend using VS Code with the PlatformIO or pioarduino extension. If you plan to develop a web application to connect the ESP8266 with Firebase, VS Code offers all the tools you need. However, since we won\u2019t be building a web application in this tutorial, you can simply use the Arduino IDE, if you prefer.<\/p>\n\n\n\n There is a library with lots of examples to use Firebase with the ESP8266: the FirebaseClient library<\/a>. This library is compatible with the ESP32, ESP8266, and many other boards.<\/p>\n\n\n\n In this tutorial, we’ll look at simple examples to store and read data from the database. The library provides many other examples that you can check here<\/a>. It also provides detailed documentation explaining how to use the library.<\/p>\n\n\n\n If you’re using VS Code with the PlatformIO extension, click on the PIO Home<\/strong> icon and then select the Libraries tab<\/strong>. Search for “FirebaseClient<\/strong>“. Select the Firebase Client Library<\/strong> by Mobitz.<\/p>\n\n\n Then, click Add to Project<\/strong> and select the project you’re working on.<\/p>\n\n\n Also, change the monitor speed to 115200 by adding the following line to the platformio.ini<\/span> file of your project:<\/p>\n\n\n\n If you’re using Arduino IDE, follow the next steps to install the library.<\/p>\n\n\n\n Now, you’re all set to start programming the ESP8266 board to interact with the database.<\/p>\n\n\n\n Copy the following code to your Arduino IDE. This sketch inserts an int, a float number, and a string into the database every 10 seconds. This is a simple example that shows how to connect the ESP8266 to the database to store data.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n You need to insert your network credentials, URL database, project API key, firebase user email and password.<\/p>\n\n\n\n This sketch was based on this basic example provided by the library<\/a>. You can find more examples here<\/a>.<\/p>\n\n\n\n Continue reading to learn how the code works, or skip to the demonstration section<\/a>.<\/p>\n\n\n\n First, include the required libraries. The ESP8266WiFi.h<\/span> library to connect the ESP8266 to the internet, the WiFiClientSecure<\/span> to create a wi-fi client, and the FirebaseClient.h<\/span> library to interface the ESP8266 with Firebase.<\/p>\n\n\n\n Include your network credentials in the following lines.<\/p>\n\n\n\n Insert your Firebase project API key\u2014the one you’ve gotten in section 4.1<\/a>.<\/p>\n\n\n\n Insert your database URL\u2014see section 3.4<\/a>.<\/p>\n\n\n\n\n
What is Firebase?<\/h2>\n\n\n
![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/Firebase-Logo.png?resize=750%2C196&quality=100&strip=all&ssl=1\"){kind=logo}
<\/figure><\/div>\n\n\n![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/ESP8266-Getting-Started-Firebase-f.png?resize=750%2C329&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/ESP8266-Firebase-Getting-Started-RTDB.png?resize=750%2C247&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nProject Overview<\/h2>\n\n\n\n
\n
\n\n\n\nSet Up a Firebase Account and Create a New Project<\/h2>\n\n\n\n
1.Create a New Project<\/h3>\n\n\n\n
\n
![\"Set](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/1-create-firebase-project.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Set](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/2-create-firebase-project-ai-assistance.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Disable](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/3-create-firebase-project.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/5-Firebase-project-ready.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure>
<\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/6-Firebase-console-ESP-project.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n<\/ol>\n\n\n\n2. Set Authentication Methods<\/h3>\n\n\n\n
\n
![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/7-set-authentication.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"SFirebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/8-Firebase-authentication-methods.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Enable](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/9-enable-email-password-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/10-add-user-email-password-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/11-add-user-email-pass.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/12-user-created-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n<\/ol>\n\n\n\n3. Creating a Realtime Database<\/h3>\n\n\n\n
\n
![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/13-create-database-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/14-database-location-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/15-database-start-test-mode-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/16-firebase-database-url.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n<\/ol>\n\n\n\n4. Get Project API Key<\/h3>\n\n\n\n
\n
![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/17-project-settings-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n\n\n\n![\"Firebase](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/04\/18-project-api-key-firebase.png?w=1200&quality=100&strip=all&ssl=1\")
<\/figure><\/li>\n<\/ol>\n\n\n\n
\n\n\n\nProgram the ESP8266 to Interface with Firebase<\/h2>\n\n\n\n
Installing the FirebaseClient Library<\/h3>\n\n\n\n
Installation – VS Code + PlatformIO<\/h4>\n\n\n\n
![\"Install](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/Install-FirebsaeClient-Library-VS-Code.jpg?resize=750%2C646&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"Add](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/Add-FirebaseClient-library-to-project-VS-Code.jpg?resize=750%2C341&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nmonitor_speed = 115200<\/code><\/pre>\n\n\n\nInstallation – Arduino IDE<\/h4>\n\n\n\n
\n
![\"Install](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/install-Firebase-client-arduino-ide.png?resize=790%2C586&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n
\n\n\n\nESP8266 Store Data to Firebase Database<\/h2>\n\n\n
![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2021\/09\/ESP8266-Store-Data-RTDB-Firebase.png?resize=750%2C401&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\/*********\n Rui Santos & Sara Santos - Random Nerd Tutorials\n Complete instructions at https:\/\/RandomNerdTutorials.com\/esp8266-nodemcu-firebase-realtime-database\/\n*********\/\n\n#include <Arduino.h>\n#include <ESP8266WiFi.h>\n#include <WiFiClientSecure.h>\n#include <FirebaseClient.h>\n\n\/\/ Network and Firebase credentials\n#define WIFI_SSID "REPLACE_WITH_YOUR_SSID"\n#define WIFI_PASSWORD "REPLACE_WITH_YOUR_PASSWORD"\n\n#define Web_API_KEY "REPLACE_WITH_YOUR_FIREBASE_PROJECT_API_KEY"\n#define DATABASE_URL "REPLACE_WITH_YOUR_FIREBASE_DATABASE_URL"\n#define USER_EMAIL "REPLACE_WITH_FIREBASE_PROJECT_EMAIL_USER"\n#define USER_PASS "REPLACE_WITH_FIREBASE_PROJECT_USER_PASS"\n\n\/\/ User function\nvoid processData(AsyncResult &aResult);\n\n\/\/ Authentication\nUserAuth user_auth(Web_API_KEY, USER_EMAIL, USER_PASS);\n\n\/\/ Firebase components\nFirebaseApp app;\nWiFiClientSecure ssl_client;\nusing AsyncClient = AsyncClientClass;\nAsyncClient aClient(ssl_client);\nRealtimeDatabase Database;\n\n\/\/ Timer variables for sending data every 10 seconds\nunsigned long lastSendTime = 0;\nconst unsigned long sendInterval = 10000; \/\/ 10 seconds in milliseconds\n\n\/\/ Variables to send to the Database\nint intValue = 0;\nfloat floatValue = 0.01;\nString stringValue = "";\n\nvoid setup(){\n Serial.begin(115200);\n\n \/\/ Connect to Wi-Fi\n WiFi.begin(WIFI_SSID, WIFI_PASSWORD);\n Serial.print("Connecting to Wi-Fi");\n while (WiFi.status() != WL_CONNECTED) {\n Serial.print(".");\n delay(300);\n }\n Serial.println();\n\n \/\/ Configure SSL client\n ssl_client.setInsecure();\n ssl_client.setTimeout(1000); \/\/ Set connection timeout\n ssl_client.setBufferSizes(4096, 1024); \/\/ Set buffer sizes\n\n \/\/ Initialize Firebase\n initializeApp(aClient, app, getAuth(user_auth), processData, "\ud83d\udd10 authTask");\n app.getApp<RealtimeDatabase>(Database);\n Database.url(DATABASE_URL);\n}\n\nvoid loop(){\n \/\/ Maintain authentication and async tasks\n app.loop();\n\n \/\/ Check if authentication is ready\n if (app.ready()){\n \/\/ Periodic data sending every 10 seconds\n unsigned long currentTime = millis();\n if (currentTime - lastSendTime >= sendInterval){\n \/\/ Update the last send time\n lastSendTime = currentTime;\n\n \/\/ send a string\n stringValue = "value_" + String(currentTime);\n Database.set<String>(aClient, "\/test\/string", stringValue, processData, "RTDB_Send_String");\n\n \/\/ send an int\n Database.set<int>(aClient, "\/test\/int", intValue, processData, "RTDB_Send_Int");\n intValue++; \/\/increment intValue in every loop\n\n \/\/ send a string\n floatValue = 0.01 + random (0,100);\n Database.set<float>(aClient, "\/test\/float", floatValue, processData, "RTDB_Send_Float");\n }\n }\n}\n\nvoid processData(AsyncResult &aResult){\n if (!aResult.isResult())\n return;\n\n if (aResult.isEvent())\n Firebase.printf("Event task: %s, msg: %s, code: %d\\n", aResult.uid().c_str(), aResult.eventLog().message().c_str(), aResult.eventLog().code());\n\n if (aResult.isDebug())\n Firebase.printf("Debug task: %s, msg: %s\\n", aResult.uid().c_str(), aResult.debug().c_str());\n\n if (aResult.isError())\n Firebase.printf("Error task: %s, msg: %s, code: %d\\n", aResult.uid().c_str(), aResult.error().message().c_str(), aResult.error().code());\n\n if (aResult.available())\n Firebase.printf("task: %s, payload: %s\\n", aResult.uid().c_str(), aResult.c_str());\n}\n<\/code><\/pre>\n\tHow the Code Works<\/h3>\n\n\n\n
Including Libraries<\/h4>\n\n\n\n
#include <Arduino.h>\n#include <ESP8266WiFi.h>\n#include <WiFiClientSecure.h>\n#include <FirebaseClient.h><\/code><\/pre>\n\n\n\nDefining Credentials<\/h4>\n\n\n\n
#define WIFI_SSID \"REPLACE_WITH_YOUR_SSID\"\n#define WIFI_PASSWORD \"REPLACE_WITH_YOUR_PASSWORD\"<\/code><\/pre>\n\n\n\n#define Web_API_KEY \"REPLACE_WITH_YOUR_FIREBASE_PROJECT_API_KEY\"<\/code><\/pre>\n\n\n\n#define DATABASE_URL \"REPLACE_WITH_YOUR_FIREBASE_DATABASE_URL\"<\/code><\/pre>\n\n\n\n