Published September 1, 2025

Clap Switch: Control LED with Sound

A simple Arduino setup using a sound sensor, your clap is detected and triggers an LED to turn on or off.

BeginnerShowcase (no instructions)3 hours6

Things used in this project

Hardware components

Arduino UNO

Seeed Studio Grove - Sound Sensor/ Noise Detector for Arduino

LED (generic)

Resistor 221 ohm

Breadboard (generic)

Jumper wires (generic)

Software apps and online services

Arduino IDE

Story

Ever wished you could turn on a light just by clapping your hands like in movies? This project makes that possible with a simple Arduino setup! By using a sound sensor, your clap is detected and triggers an LED to turn on or off. It’s a fun and interactive way to explore sound-based control systems, perfect for beginners experimenting with sensors and automation.

Hardware Components

Arduino Uno (1x)

Sound Sensor Module (1x)

LED (1x)

Resistor (220Ω, 1x)

Breadboard (1x)

Jumper Wires

Software

Arduino IDE

Circuit Diagram

circuit

Connections:

Sound Sensor OUT → A0 on Arduino

Sound Sensor VCC → 5V, GND → GND

LED Anode → Digital Pin 7 (via 220Ω resistor)

LED Cathode → GND

Code

Arduino Code

// Clap Switch Project
// Turns LED on/off with a clap sound

const int soundSensor = A0;   // Sound sensor connected to A0
const int ledPin = 7;         // LED connected to digital pin 7
int sensorValue = 0;
bool ledState = false;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(soundSensor, INPUT);
  Serial.begin(9600);
}

void loop() {
  sensorValue = analogRead(soundSensor);
  Serial.println(sensorValue);

  if (sensorValue > 500) { // adjust threshold based on your environment
    ledState = !ledState;  // toggle LED state
    digitalWrite(ledPin, ledState);
    delay(500); // debounce delay
  }
}