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

Building a voice controlled home automation system with an Arduino and Alexa is an exciting project that allows you to control devices and appliances in your home using voice commands. With some basic hardware, software configuration, and coding, you can set up a system to switch lights on and off, adjust thermostats, lock doors, and more with simple voice interactions. Here is a step-by-step guide on how I built my own DIY voice controlled home automation system.

Hardware Needed

To build the home automation system, I used the following hardware components:

Software Setup

On the software side, I needed to install the following:

Wiring the Circuit

I first wired up the Arduino, relay modules, and other components on a breadboard as follows:

I tested the circuit by uploading a simple Arduino sketch to switch the relays on and off before moving on to voice control integration.

Coding the Arduino Sketch

The Arduino needs to run a sketch that can switch the relays on and off based on commands received from the IFTTT webhooks.

I used the following key steps when coding the sketch:

I tested the sketch thoroughly before integration with IFTTT.

Creating IFTTT Applets

IFTTT provides the glue between the Alexa voice commands and the Arduino by using webhooks.

To create the integration, I performed these steps:

Now the IFTTT applets will send webhook requests to the Arduino when voice commands are said.

Putting It All Together

With the hardware assembled, Arduino coded, and IFTTT applets created, it's time to put it all together for voice controlled automation.

I can now control multiple appliances and devices in my home through conversational voice commands using this DIY Arduino and Alexa home automation system!


Creating your own voice controlled home automation system is an achievable and engaging project for makers of all skill levels. With the help of an Arduino, relays, and Alexa integration via IFTTT, you can set up voice control of lights, motors, switches, and more. I encourage you to experiment with the capabilities and customize the system to automate the devices in your unique home. The ability to command your home environment with simple voice interactions opens up tremendous convenience, accessibility and fun.