How to Build an Arduino Voice Controlled LED for Your Room with Minimal Materials

How to Build an Arduino Voice Controlled LED for Your Room with Minimal Materials


Building an Arduino voice controlled LED for your room is a fun electronics project that allows you to control lights and other devices with simple voice commands. With just a few cheap components, you can set up a basic but powerful voice control system with surprisingly little effort. In this guide, I'll show you step-by-step how to build your own Arduino voice controlled LED using minimal materials.

What You Will Need

To build an Arduino voice controlled LED, you will need the following components:

That's it for the core components! Optionally, you can also add:

All of these components can be picked up very cheaply. The total cost should be under $15.

Circuit Diagram

Here is the circuit diagram showing how to connect the components:

The microphone connects to analog pin A0 to capture your voice. The LED connects through a resistor to pin D8. Optionally, a transistor can amplify the output to make the LED brighter.

Arduino Code

The code for this project has two main parts:

  1. Voice recognition - This monitors the microphone input and detects trigger words like "on" and "off".
  2. LED control - This turns the LED on or off based on the detected trigger word.

Here is a simple Arduino sketch to demonstrate the basic functionality:

// Set pin numbers
const int ledPin = 8;
const int micPin = A0;

void setup() {
// Initialize LED pin as output
pinMode(ledPin, OUTPUT);

// Initialize serial

void loop() {

// Check if "on" is detected
if(checkForVoice("on")) {

// Turn LED on
digitalWrite(ledPin, HIGH);

// Provide feedback
Serial.println("LED turned ON");


// Check if "off" is detected
if(checkForVoice("off")) {

// Turn LED off
digitalWrite(ledPin, LOW);

// Provide feedback
Serial.println("LED turned OFF");



// Voice recognition function
boolean checkForVoice(String keyword) {

// Record audio and check if keyword is found
// ...

// Return true if keyword found, false if not

This gives you an idea of the basic structure. The voice recognition part needs to be expanded to actually analyze the audio input. There are Arduino libraries like EasyVR that can help with adding robust voice recognition.

Assembling the Circuit

Once you have all the components and code ready, it's time to assemble the circuit:

  1. Insert the Arduino and breadboard into a holder to keep them secure.

  2. Insert the microphone into the breadboard and connect to pin A0 with a jumper wire.

  3. Insert the LED and resistor into the breadboard. Connect resistor to pin D8.

  4. Connect Arduino 5V and GND pins to power rails on the breadboard.

  5. Upload the Arduino code you prepared earlier.

  6. Open the Arduino IDE serial monitor to see printed feedback.

  7. Test it out by speaking your trigger words ("on" and "off") clearly near the microphone. The LED should turn on and off each time.

And that's it - you now have a voice controlled LED with Arduino!

Going Further

Here are some ideas for improving and expanding this project:

The possibilities are endless! With just a simple microphone-enabled Arduino, you can build all kinds of creative voice-controlled projects.


Building voice-controlled devices is fun and surprisingly easy with Arduino. This project shows how you can use an Arduino, microphone and LED to create a simple voice controlled light with just a few components.

The full Arduino code and circuit diagram provided gives you a template to get started. From there, you can expand the project by adding more outputs, improving speech recognition, and integrating it into larger projects. Voice control adds an interactive element that can make your Arduino creations more engaging.

So give it a try, and see what voice controlled projects you can dream up! With an Arduino, a mic, and a bit of coding, you can build your own talking creations.