An Audio Level Indicator (VU meter) or a volume unit meter, are electronic devices that display the intensity of any Input audio signal, usually in musical pieces of equipment (Drum sets, mic, electric guitars, amps, speakers, etc.). More specifically, it helps to visualize analog signals. So, In this project, we are going to design a simple Audio Level Indicator (VU meter) using the LM3914N dot/bar display driver IC
Hardware Required
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You will need the following parts to build this project.
- 1x LM3914 LED Driver IC.
- 10x RED LEDs
- Suitable Audio Input (Condensor Microphone/Smartphone)
- 3.5mm Audio jack port (Male)
- 470K Pot
- Resistors (1.2K)
- 12V DC Power Supply
- Breadboard
- Connecting Wires
Steps
Solder IC Base
Solder All LED’s
Solder Potentiometer & 1.2K Resistor
Solder Electret Mic
Cut Signal Wire of audio cable
Solder Audio Cable in Paralell to Mic
Solder Power Connector
Let’s Powerup the Circuit
Circuit Diagram

The LM3914 was an old favorite of mine. Nice to see it in action again.