Controlling RGB LED from Android Application and ESP8266 WiFi Module in real-time

A step-by-step guide to creating your first IoT project for beginners

4 min readJan 25, 2021

A little back story

When I first saw IoT based Android Application that can control all the home appliances with a simple touch from the app, I was awestruck. So I researched about it and found it’s much simpler than it looks. You can follow this article and create this app without prior knowledge of android programming or ESP8266 WiFi Module. To proceed any further let’s keep all hardware & software handy.

Hardware Requirements:

Android mobile
ESP8266 WiFi Module
Breadboard
Jumper wire (M/M)
USB 2.0 cable
Common Cathode LED

Software Requirements:

How this will work

First I will show you how to set up the Firebase Realtime Database and connect with our ESP8266 WiFi Module code. Then we develop a simple Android application and will connect with Firebase Realtime Database.

Selecting any color from ColorPickerView in the application will change the value in the database and trigger the color change in RGB LED.

Let’s set up the Firebase Realtime Database.

Firebase Realtime Database

Why Firebase Realtime Database?

Firebase allows us to easily set up listeners that can trigger client code when any data is modified and giving end-users real-time updates.

2. Setting up Firebase Realtime Database

It’s a very simple process to set up Firebase Realtime Database. You can follow this youtube video.

Configuring the Hardware

The most difficult part when working with IoT projects is wiring & setup. In order to work as a complete product, hardware(ESP8266 WiFi Module) & software(Android app) need to work as a single unit. In order to achieve that, let’s install the Arduino IDE first.

Arduino IDE installation

Arduino IDE is available for all 3 major OSs. You can download from here and install.

2. Add Firebase Arduino library to your project

In order to communicate your Arduino code to the Firebase Realtime Database, you need to install one library.

Open Arduino IDE, go to menu Sketch -> Include Library -> Manage Libraries…

In the Library Manager Window, search for “Firebase” and then select “Firebase ESP8266 Client” and click the “Install” button.

3. Setting up Firebase Realtime Database

4. Circuit Design

Developing Android Application

Open your Android Studio and Click on Create New Project, In the Project Template Window, Select Empty Activity and click on Next. Enter Application Name and click Finish.

Adding internet permission

Open AndroidManifest.xml and internet permission

<manifest 
xmlns:android="http://schemas.android.com/apk/res/android"
...>
<uses-permission android:name="android.permission.INTERNET"/>
</manifest>

2. Adding the dependency

Add the below library in your project build.gradle file

dependencies {
implementation 'com.google.firebase:firebase-database:16.0.1'
implementation "com.github.skydoves:colorpickerview:2.1.5"
}

Add the below library in your module build.gradle file

dependencies {
classpath 'com.google.gms:google-services:4.0.1'
}

3. Android Layout file

Here I used a library to pick a color. I have used the ColorPickerView library, it’s much simpler to implement and extract the RGB color code with very little effort.

4. Activity File

Here we initialize the Firebase Realtime Database, pick the color code from the ColorPickerView library, and send it to Realtime Database.