A VU metre is volume unit (VU) meter or standard volume indicator (SVI) is a device displaying a representation of the signal level in audio equipment. It is used to visualise the Analog signal .
Now I am going to instruct how to make a VU meter using Arduino with less number of components.
Step 1: Components Required
Arduino Uno (with Adaptor or 9V battery) [ DigiKey]
Resistors - 100 Ohm (x11) [ DigiKey]
LEDs (Different Colours) - 11
Hookup wire - 1.5 to 2 meters [ DigiKey]
3.5 mm Audio Jack -1 [ DigiKey]
PCB -1 [ DigiKey]
Step 2: Circuiting
Insert LEDs into PCB such that all Positive terminals are in same side.
Insert Resistors into PCB in series with Positive terminal of the LEDs .
Solder wires to 3.5mm audio jack.
Solder all components according circuit.
Use Hookup wire to connect in series with resistor to Arduino digital pins.
Upload the code into arduino.
Insert one wire of audio jack at A0 and another to GND.
Here the circuiting completes
Insert Audio Jack to any audio source and test the circuit.