Turn Your Lights on With Clapping?!





Introduction: Turn Your Lights on With Clapping?!

Wouldn't it be nice to turn on your lights without getting off the couch? In this project I am going to show you how to build a simple Arduino clap circuit which can turn on and off all kinds of AC appliances. Let's get started!

Step 1: Watch the Video!

The video gives you an overview on how to build this project. But I am going to present you more detailed information in the following steps to make your life easier.

Step 2: Order Your Parts!

Here you can find a list of all the components with example sellers:


1x ATtiny85: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x NE5534: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x IC Socket: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Electret Microphone: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 20kΩ Potentiometer: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Knob: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Resistor Kit (various): http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 100nF Capacitor: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 1N4002 Diode: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x BC 637 NPN Transistor: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x FRS1B-S-DC05 Relay: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Power Supply 230V/5V 500mA: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x AC Socket (Input): http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x AC Socket (Output): http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

Bridge Wire: -

Shielded Wire: -

AC Wire: -


1x ATtiny85: http://amzn.to/1hPDkQp

1x NE5534: http://amzn.to/1NzwvOP

2x IC Socket: http://amzn.to/1MCbdj0

1x Electret Microphone: http://amzn.to/1MCbkuU

1x 20kΩ Potentiometer: http://amzn.to/1MCbAKp

1x Knob: http://amzn.to/1hPDCGP

1x Resistor Kit (various): http://amzn.to/1NzwL0l

1x 100nF Capacitor: http://amzn.to/1hPDF5u

1x 1N4002 Diode: http://amzn.to/1MCbLFz

1x BC 637 NPN Transistor: http://amzn.to/1hPDM0S

1x FRS1B-S-DC05 Relay: -

1x Power Supply 230V/5V 500mA: -

1x AC Socket (Input): http://amzn.to/1MCbX7H

1x AC Socket (Output): http://amzn.to/1LmTI4r

Bridge Wire: -

Shielded Wire: -

AC Wire: -


1x ATtiny85: http://amzn.to/1E9ubfB

1x NE5534: http://amzn.to/1MHZjp7

2x IC Socket: http://amzn.to/1Nzv6aZ

1x Electret Microphone: http://amzn.to/1E9unLZ

1x 20kΩ Potentiometer: http://amzn.to/1E9up6B

1x Knob: http://amzn.to/1E9uzeb

1x Resistor Kit (various): http://amzn.to/1E9uEhN

1x 100nF Capacitor: http://amzn.to/1PpxLCz

1x 1N4002 Diode: http://amzn.to/1E9uKGd

1x BC 637 NPN Transistor: -

1x FRS1B-S-DC05 Relay: -

1x Power Supply 230V/5V 500mA: -

1x AC Socket (Input): http://amzn.to/1FIc7b5

1x AC Socket (Output): http://amzn.to/1MHZZeh

Bridge Wire: http://amzn.to/1Ppyh3B

Shielded Wire: -

AC Wire: http://amzn.to/1E9vmvw


1x ATtiny85: http://amzn.to/1E9xqDR

1x NE5534: http://amzn.to/1PpzAzw

2x IC Socket: http://amzn.to/1NzxoqD

1x Electret Microphone: http://amzn.to/1Nzxpem

1x 20kΩ Potentiometer: http://amzn.to/1Nzxv5E

1x Knob: http://amzn.to/1NzxxKR

1x Resistor Kit (various): http://amzn.to/1NzxNJR

1x 100nF Capacitor: http://amzn.to/1MI20Hp

1x 1N4002 Diode: http://amzn.to/1PpzVSG

1x BC 637 NPN Transistor: http://amzn.to/1MI21Lw

1x FRS1B-S-DC05 Relay: -

1x Power Supply 230V/5V 500mA: -

1x AC Socket (Input): http://amzn.to/1PpAdcc

1x AC Socket (Output): http://amzn.to/1NJmZGM

Bridge Wire: http://amzn.to/1PpAcFf

Shielded Wire: http://amzn.to/1E9ynfm

AC Wire: http://amzn.to/1NJn8Kv

Visit your local hardware store to get your screws, nuts and different connectors.

Step 3: Build the Circuit!

Here you can find the schematic and veroboard layout to create your own clap circuit. I recommend to build it firstly on a breadboard to test the circuit before moving it over to a stripboard.

Step 4: Program the ATtiny85!

Use the given sketch to program your ATtiny85. If you don't know how to do this with an Arduino Uno then have a look at my previous video about the subject:

Step 5: Get the Wiring Done!

With the help of the pictures you should be able to see which wire connects to which connector. As I mentioned in the video 230V can kill you, be careful!

Step 6: Success!

You did it. You just created your own clap circuit!

Feel free to check out my YouTube channel for more awesome projects:


You can also follow me on Facebook, Twitter and Google+ for news about upcoming projects and behind the scenes information:



4 People Made This Project!


  • Epilog Challenge 9

    Epilog Challenge 9
  • Pocket-Sized Contest

    Pocket-Sized Contest
  • Science of Cooking

    Science of Cooking

We have a be nice policy.
Please be positive and constructive.



What program are you using to create schematics?


I made this circuit myself today and, apart form working properly sometimes, i often encounter these 2 problems:

1 - i had to use NE5532 opamp ic and it often delivers constant 4.7V to the ATtiny so the code can never sense low treshold value

2 - it works but very unreliably. Sometimes it works with one clap, it triggers randomly if i just talk near the microphone. Is there any way to improve it?

It possible to replace the bc637 to other transistor i cant buy here in my country


I have a question. What is the red squares?

It's where you need to cut the conductive bord

It possible to replace the relay 5v 6pin to relay 5v 5pin?

Is or are there any alternatives/ equivalent to the BC 637 transistor? I'm kinda having troubles finding one here in my country. Cool project though!

Hi, Im having some issues opening the program.. after I download it and open, it says "-

-need to be inside a sketch folder names F3HVWGOIDOCVU9E, creat this folder, move the file and continue?

when I say yes, it says again

-A folder name f3HV etc, already exist. Cant open sketch.

and when I say Okay

-It said, Failed to open sketch "C:/User etc.

and wont open, I need help..

Also I had built a similar circuit, I was happy to see I built it close to this one, my code is a little different, but same Idea. I happened to be looking at Op Amp information and ran across this. I'm surprised I did not see it earlier, since I do watch GreatScott and I'm glad he shares.. This is great for people starting out.. Also I did not use AC, I used it for solar lighting at 12v. But this is a great way to start, I would just suggest isolating Mains voltage more.. But I love it..

Please tell me