Light Pulser

Project Overview

A device that flashes lights in response to sound.

Technical Details

I have always loved concert visuals. The way the lights pulse and change color in repsonse to the music is mesmserizing to me. I wanted to create a small device that could replicate this in my room. At this point in my circuitry journey, I understood the basic of both digital and analog circuits, but I had never integrated the two. I started by buying a strip of LED lights, which came with a small controller PCB. Decoding this proved challenging, as the Datasheet was in Chinese, and the Serial pins had been disabled by the manufacturer. I was a bit fed up at this point, and just scratched my way into the signal line for the lights, attaching my own nano's output pins to the controller. Next, I had to find a way to tap into the music itself without affecting the quality of the signal. I accomplished this using a tl072, an op amp with a famously high impedance. I used this to create a simple non inverting amplifier, which I could use to boost the signal from my aux cable to a level that the arduino could read. Finally, I biased the signal up to 2.5 volts (a level the arduino could read.) Using the Fast Fourier Transform library, I was able to analye the frequency content of the signal, and map the frequency of the music to an RGB spectrum.