It is, of course, possible to realize such a circuit entirely using only discrete components, but in this article we will show you how you could build one using an Arduino and a multipurpose shield. Besides the LEDs there is also an LCD that operates as a VU meter and with a few pushbuttons it is easy to set the different thresholds.

elektor

This is an excellent project to gain some programming experience with an Arduino! This circuit demonstrates all kinds of things:
- Sound-level measurements with an Arduino
- Generating an alarm
- Digital filtering
- Driving an LCD
- Driving LEDs
- Reading switches
- Implementing a Setup menu
- Displaying a bar graph
- Using LCD custom characters
- Storing and then retrieving values from the EEPROM

Do you like this Sound-Level Protector? Want to read more? Download the full article for free as a PDF file in the 'Attachment' section below.