This instructable will show you how to create a LED beer bottle VU Meter. A volume unit meter is a device that is used to display a relative volume of audio signals. Basically, sound gets converted into electricity, then amplified and run into a dedicated IC (Integrated Circuit). The IC then determines the level of sound and outputs it accordingly onto its outputs. This particular VU Meter uses a LM3915 Dot/Bar Display Driver to determine the sound level. This circuit is more flexible than a regular VU Meter though, due to the fact that I incorporated a microcontroller into the project. This makes it a little more complex, but also way more flexible.
The main reason that I built this project is because I have always been fascinated with LEDs. There is just so many cool projects that a person can make with them. Also, a couple years ago I made a Chevrolet logo VU Meter which didn't use a microcontroller. Although it was really cool, there wasn't a lot that I could do with it once it was made. I had the options of bar mode or dot mode and that was it. With the help of a microcontroller, you can design a project so that you are able to turn on any individual LED or groups of LEDs at any of the 10 different sound levels. That makes things a little more challenging, but also more interesting.
By following each and every step, you will be able to complete your own beer bottle LED VU Meter just like this one. Or if you are feeling really ambitious, create your own customized LED VU Meter and just use this instructable as a guideline.