DIY Arduino FFT Audio Spectrum Visualizer

Greetings everyone, and welcome to my article tutorial. Today, I'll guide you through the process of creating an Arduino audio spectrum on LED dot matrix 4-in-1 display.

Project Overview:

We'll guide you through building your very own audio spectrum visualizer from scratch! Using a popular Arduino Nano microcontroller and a vibrant MAX7219 dot matrix display, you can bring any audio to life. This visualizer dynamically analyzes sound frequencies in real-time, creating a stunning light show that dances to the beat. Follow our step-by-step tutorial to assemble the circuit, upload the code, and create this awesome gadget for your desk or music setup!

Technically, the project works by feeding an audio signal to the Arduino, which then uses a Fast Fourier Transform (FFT) library. The FFT algorithm analyzes the signal, breaking it down into its constituent frequency bins. The magnitude of each frequency bin is then visually mapped as a corresponding column height on the dot matrix display, creating the real-time spectrum effect.

Before beginning, a huge shoutout to JLCMC for sponsoring.

Now, let's get started with our project!

Supplies

Electronic Components Required:

1. Arduino Uno
2. MAX7219 LED Dot Matrix 4 In 1 Display
3. Sound Sensor
4. Breadboard
5. Cardboard

Additional Tools:

1. Hot Glue
2. Cutter

Software:

1. Arduino IDE

Step 1: Breadboard Circuit

Follow the steps:

1. Mount the Arduino Nano into the breadboard, as shown in the image.
2. Connect the female-to-male jumper wire at one end to the MAX7219 LED Dot Matrix Display input terminals. i.e., VCC, GND, DIN, CS, and CLK pinouts.
3. Connect the male terminal of the jumper wire from the MAX7219 LED Dot Matrix Display to the following pins: VCC -> 5V, GND -> GND, DIN -> D11, CS -> D10, and CLK -> D13 pins of the Arduino Nano. The table of the pin configurations is attached.
4. Now we will use another female-to-male jumper wire to connect the Sound Sensor with the Arduino Nano. Connect the jumper wire's female terminal with the Sound Sensors's VCC, GND, and OUT.
5. Connect the male terminal of the jumper wire from the Sound Sensor to the following pins: VCC -> 3.3V, GND -> GND, OUT -> A0 pins of the Arduino Nano. The table of the pin configurations is attached.

Connect the USB to your Arduino Nano.

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Step 3: Coding Time!

Before we proceed with the coding process, make sure to install the following library with these version numbers; otherwise, you will get the errors:

arduinoFFT.h --> v2.0.4 MD_MAX72xx.h --> v3.5.1

Now, copy and paste this code into your Arduino IDE:

#include <arduinoFFT.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
MD_MAX72XX disp = MD_MAX72XX(MD_MAX72XX::FC16_HW, 10, 4);
arduinoFFT FFT = arduinoFFT();
double realComponent[64];
double imagComponent[64];
int spectralHeight[] = {0b00000000,0b10000000,0b11000000,
                        0b11100000,0b11110000,0b11111000,
                        0b11111100,0b11111110,0b11111111};
int index, c, value;
void setup()
{
  disp.begin();
  Serial.begin(9600);
}
void loop()
{
  int sensitivity = map(analogRead(A0),0,1023,50,100); 
  Serial.println (analogRead(A0));
  for(int i=0; i<64; i++)
  {
    realComponent[i] = analogRead(A0)/sensitivity;
    imagComponent[i] = 0;
  }
  FFT.Windowing(realComponent, 64, FFT_WIN_TYP_HAMMING, FFT_FORWARD);
  FFT.Compute(realComponent, imagComponent, 64, FFT_FORWARD);
  FFT.ComplexToMagnitude(realComponent, imagComponent, 64);
  for(int i=0; i<32; i++)
  {
    realComponent[i] = constrain(realComponent[i],0,80);
    realComponent[i] = map(realComponent[i],0,80,0,8);
    index = realComponent[i];
    value = spectralHeight[index];
    c = 31 - i;
    disp.setColumn(c, value);
  }
}

Step 4: Let's Make a CASE for It

To construct the case, I will use cardboard. The PDF file containing the cardboard cutout templates is attached below. Please refer to the accompanying images for guidance on assembling the case for this project.

Step 5: Working Video and Tutorial

Congratulations! You’ve successfully built your Arduino Audio Spectrum on LED Dot Matrix 4 In 1 Display. A demonstration video of this project can be viewed here: Watch Now

Thank you for your interest in this project. If you have any questions or suggestions for future projects, please leave a comment, and I will do my best to assist you.

For business or promotional inquiries, please contact me via email at Email.

I will continue to update this article with new information. Don’t forget to follow me for updates on new projects and subscribe to my YouTube channel (YouTube: roboattic Lab) for more content. Thank you for your support.