Picture of Arduino vu meter with amplifier
Your four main parts for this project are an Arduino, a LoLshield, and an amplifier

The LoLshield is a circuit board that comes with a library that enables one to individually control a matrix of LEDs.  Once you have the correct library installed you can use the code LedSign::Set(x,y,1); to individually choose one led to turn on with your limited number of pins on the arduino. 

Instructions on how to construct the LoLshield can be found here ( 

For our amplifier we choose to use the O2 NwavGuy amp.  For information on ordering and/or constructing follow this link,
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Step 1: Connections

Picture of Connections
Now that you have your two main components you need to start connecting them.  You music signal need to go both to the amplifier. Solder two wires to the input jack of the circuit bored like so.

Step 2: Power control

Picture of Power control
In order to ensure that you don’t over power the arduino you will have to solder in a 330 Ω   resistor and a .01 μF capactor in series with the gray wire.

Then just connect the capacitor to pin A4 on the LoLshield and the black wire to the GND pin.
In your video whats is up with the far right hand column of LEDs also after the music stops there is still some action from the other LEDs is this noise in the signal input or is it a bug in the coding?
Still great project, one of the few I've seen that uses an Arduino... Most use either the LM3915 or the LM3916.
amaxrich (author)  BrefelanDesigns2 years ago
It was noise. The code is solid. For the start is was running perfectly however it started to show noise as it went on. We believe we joined a connection on our led board and decided it wasn't big enough a problem to find the bad connection.
mattross2 years ago
Why are you using an amp instead of a mic and gain control? That would give you better control over the sensitivity of the lights. But would it be more difficult?
amaxrich (author)  mattross2 years ago
The amplifier is used to boost the quality of the music, and we don't need a microphone because the arduino is wired directly to the source