How to Build a Voice Controlled Home Automation System with an Arduino and Android App


Building a voice controlled home automation system is an exciting project that allows you to control devices and appliances in your home using voice commands. With some basic electronics components like an Arduino microcontroller and Android smartphone, I can create a simple yet powerful home automation system.

In this guide, I will walk through the end-to-end process of building this system, including:

By the end of this guide, I will have a custom voice controlled home automation system that can:

So let's get started on learning how to build this amazing voice controlled home automation system.

Hardware Needed

The hardware components I will need for this project are:

This looks like a long list, but all these components are easily available and cheap. The total hardware cost would be around $50 - $60.

Setting up the Arduino

The first step is to assemble the circuit using the Arduino, Bluetooth module, relays, transistors and other components.

The Arduino will be the brain of this home automation system. It will receive wireless voice commands from the Android app via Bluetooth and actuate the relays to control the appliances.

Here are the key steps I need to follow to setup the Arduino:

Once the hardware is ready, it is time to move on to programming the Arduino.

Programming the Arduino

The Arduino sketch has to perform two main tasks:

  1. Receive voice commands via Bluetooth
  2. Execute actions by turning relays ON/OFF

To achieve this, I will structure the sketch into three parts:

1. Initialization

2. Bluetooth Data Reception

3. Command Execution

Use if-else statements to match received commands and execute actions:

if (command == "living room light on") {
digitalWrite(livingRoomLight, HIGH);

else if (command == "bedroom fan off"){
digitalWrite(bedroomFan, LOW);

The full Arduino sketch combines these three sections to receive and execute voice commands to control the appliances.

Creating the Android App

With the Arduino automation system ready, I will now create an Android app to send voice commands to the Arduino via Bluetooth.

The app will need two core features:

1. Bluetooth Connection to Arduino

2. Voice to Text Conversion

Additionally, I can create a nice UI with buttons to record voice commands and review sent commands.

Using Android Studio to develop this app, I can quickly build an intuitive voice controller app for my home automation system.

Connecting Appliances for Automation

With the Arduino and Android app ready, I can now connect various appliances in my home to the relays on the Arduino board.

Some examples of appliances that can be automated are:

The relays act as switches that the Arduino can turn ON/OFF on command. Almost any appliance can be connected to the relays to bring it under voice control.

I can also use sensors like PIR motion detectors to make the automation context-aware. For example, motion sensed in a room can switch the lights on automatically.

Testing and Usage

With all the hardware and software ready, it is time to test my DIY voice controlled home automation system!

To use the system, I simply:

I can keep adding appliances to automate and expand the Arduino program to support more voice commands.

Some examples of voice commands for home automation:

And that's it! With this project I can fully automate my home devices using voice commands for safety, convenience and fun.


Building a voice controlled home automation system is an achievable and rewarding DIY project with huge benefits.

With basic skills in Arduino programming and Android app development, I can create my own smart home system at a fraction of commercial solution costs.

This project also serves as a great learning experience for Arduino-based electronic projects, Android app development, and Bluetooth communication.

So go ahead, get your components ready and start tinkering - your own J.A.R.V.I.S or Friday awaits! Feel free to reach out in comments if you need any help.