LED bar graph to electrolyte mic

Hey guys!

I have a question. I need a little help setting up my project. I want to have 6 LEDs act as a bar graph that reacts to sound. The louder the sound (from a electrolyte microphone), the more LEDs in a row light up. I also want to be able to increase the sensitivity of the mic with a potentiometer. Can somebody help me out with the code and maybe how to set this up?



The quickest and easiest way to do this is to use an LM3914, its a purpose designed chip for audio power metering, its widley available, cheap and easy to use. Search your favorite video site and you will find lots of examples and tutorials for using it.

Duane B


Look at the arduino esplora schematic, that has a dual op amp set up that will do exactly that. Just change the feedback resistor on the first op amp to a pot. What this is, is an amplifier followed by a peak detector.