A VU meter indicates the Volume Unit, mostly of audio equipment. A VU meter is used to get a sense of the loudness of the signal. A VU meter can also be used in any other equipment to measure intensity levels.

The project uses the ATMEGA328, which reads the input of the analog port ADC0 which is PORTC.0. The result will show in a row of 16 Leds connected to PORTD and PORTB. The input can be a variable DC voltage provided by a potentiometer with its three terminals connected to VCC, GND, and PORTC0. It can also be an input waveform connected between PORTC.0 and GND. If the input is a waveform its minimum and maximum amplitude levels must be limited to GND and VCC, respectively. The result shown a the LEDs can have a lineair or logaritmical scale. To display the voltage input in a lineair scale, the input signal would be divided with a constant number. For the logaritmic scale a lookup table could be easily employed. See the picture below.