Introduction: Light Box (using Frequency)

Hi everyone!

This post is made by Sergio García Calvente, Tatiana Castillo Pérez y Míguel Macías Macías to show you our project, this project was for 'Creative Electronics' a Beng Electronics Engineering 4th year module at the University of Málaga, School of Telecommunications(

When teachers told us to make a project with Arduino the first idea we had was to make something using music and lighst but in special we wanted to do something portable.

To explain how we make this, we'll split the project in 4 steps:

  • Step 1: Make the box.
  • Step 2: Solder the circuit.
  • Step 3: Put the lights.
  • Step 4: Make the code.

To make the project we use:

  • 1 Arduino Leonardo.
  • 1 Strip board.
  • 1 Microphone.
  • 1 Terminal block.
  • 24 White leds.
  • Some RGB LED stipt light.
  • Wires.
  • 2Hinges.
  • Some wood.

If you need to amplify the output signal from the microphone:

  • 1 2N2222A transistor.
  • 2 110nF Capacitors.
  • 2 10k Resistors.
  • 1 100k Potentiometer.

If you need to use a voltage regulator:

  • 1 7805 Voltage regulator.
  • 1 330nF Capacitor.
  • 1 110nF Capacitor.

Step 1: Make the Box.

First of all is to make the wood box, you can buy or recycle one if you want.

The process to make the box is:

  1. Mark the dimensions in the wood.
  2. Cut the pieces and sand down them.
  3. Make the holes with a drill.
  4. Paint the pieces.
  5. Join the pieces with wood glue or silicone.
  6. Use a hinge to join the top one.

Step 2: Solder the Circuit.

As we need to amplify the output signal from the microphone, we include an amplifier.

The 100k potentiometer is used to regulate the gain of the amlifier.

Some LED stript light needs 12V to work correctly so we use a 7805 voltage regulator. Now we can use 12V in the LED strip and 5V in the rest of components.

In the images we show you the schematic of the circuit that we solder.

Step 3: Put the Lights.

We solder 2 squares with 12 LED to put in the holes that we drilled in the box. Between the squares we add 6 LED strip with 6 LED each one.

In the schematic we show how to connect LEDs with Arduino and DC regulator.

Step 4: Make the Code.

As we said in the introduction we want to use one different colour for each frequency band. We use the FFT Arduino library to calculate the Fourier Transform of the signal that we read from the microphone. In the code we set the point to calculate the Fourier Transform at 64 so we take an output of 32 bits with the amplitude for each frequency band.

We can't use the first and second band because their are so noisy. We use the 3...6 band to turn on the white colour, 7...14 band to turn on the red one, 16...23 to turn on the green one and the last 8 bands to turn on the blue one.

Step 5: Enjoy!

We finished the process! Now you can enjoy the music with your new light box. It will bright according to the music you are listening at each moment.

FFT library web:

Arduino web:

Sensors Contest 2017

Participated in the
Sensors Contest 2017