January 29th, 2014

A simple circuit, and accompanying source code for a really cool looking real-time audio waveform display.
Audio is captured from a simple electret microphone, passed through an op-amp and then to the Arduino where it is processed so that it can be output to an LED dot matrix display. The code below is optimised for the Sure 24x16 display, but it can be easily altered to work with any LED display.
Watch a video of this in action on YouTube.
download the latest version as a zip file
Fritzing format PCB layout file and schematic
Arduino source code


  • Arduino powered audio waveform display
  • LM386N-1 opamp

Parts Required

  • PCB or build it on a breadboard
  • Arduino microcontroller (PICAXE code coming soon..)
  • LM386N-1 opamp (or similar)
  • Electret microphone
  • 3x 10k resistors
  • 1x 10uf capacitor
  • 2x 0.1uf capacitors
  • 1x 2.2k resistor
  • 1x 100k trimmer pot
  • Dot matrix LED display (code works with Sure 24x16)






Maximum Octopus is dedicated to the art of software development. Whether it's the development of a custom application, mobile app, or providing testing/QA feedback on an in-development project - we can do it, and we can do it to a very high standard. 

Please get in touch and let us know your development requirements!



Latest news

May 13th, 2016

Maximum Octopus proud to announce takeover of the Drop the Chicken franchise.

April 14th, 2016

New apps, Feltz and Monster Feltz, now available!

April 13th, 2016

New website now live!

March 30th, 2016

A new update to the LED Matrix Studio uploaded. Version 0.8.7 fixes a couple of minor bugs