In this tutorial we will show you how to build an Auto Brightness Adjusting LED Strip
This project is a sound meter shown by LEDs. It makes use of an electret microphone, op amp, and LM3914 LED Driver IC. How it is used is the louder the environment around the sensor is, the more LEDs are turned on by the LM3914. It’s a fairly simple and interesting project that’s ideal for newcomers to electronics.