Making a Sound Meter with a Microphone

OVERVIEW

A sound meter lets you measure how loud a sound is.

The LM358 IC and the polarised capacitor need to be orientated correctly. See below for details.

STEP 1: Open this file and upload it to Arduino.

This sketch displays the value of A0 (microphone input) on the Serial Monitor. You should see a running display of numbers.

STEP 2: Close the Serial Monitor. You want to free up the pin for the Serial Plotter.

STEP 3: Open the Serial Plotter.

Make some sounds close to the microphone and see how the display changes.

STEP 1: Upload the following program into Arduino.

STEP 2: Open the Serial Plotter. Make some sounds and see how the value changes on the Serial Plotter.

The program in Part 3 introduces local variables. Below describes the difference between local variables and global variables.

STEP 3: With this sound meter, there are many projects you can try out. Here are some examples.

Sound visualiser

Example of a clap switch