This project will take in an audio signal and convert it into a 7x7 LED grid display.

Audio Visualizer


This project acts as an "in line" display for an audio signal. The audio signal is brought into the board through a headphone style 3.5mm jack. The left and right channels are combined to mono and sent to the MSGEQ7. The MSGEQ7 breaks the signal into seven bands and sends the data to the Arduino Uno. The Arduino Uno converts each frequency into an number between 1 and 7. This number is the number of LEDs turned on for each band.

I used two headphone plugs to allow the audio signal to "pass through" my circuit, i.e. you can plug the audio signal into one side, and plug a set of speakers into the other with no loss of signal. I had to do some interesting things with the code so only one or two of the LEDs are actually on at a time. It uses persistence of vision to let you see the waveform. I will post the code soon.

Part List

  1. 1 x Arduino Uno
  2. 1 x MSGEQ7
  3. 2 x 0.1 uF capacitors
  4. 1 x 100 nF capacitor
  5. 1 x 33 pF capacitor
  6. 1 x 200K resistor
  7. 2 x 2.2K resistors
  8. 2 x 3.5mm Stereo Jacks