Now this is a multipurpose project. Use it as a party light OR as a gig booster.

Adding colors and manipulating the light sequence is easy thing to do.

Check the video to see the project in work.

If there is a VOTE patch on the right side of the project site, throw me a vote if you want :)

Step 1: Components

First thing first. Components.

Consider that this project can be done much smaller with Arduino nano or any small programming board. I made this with Arduino Uno for two reasons. 1. At the time i did not have any smaller programming board available and 2. I't is easier for beginner to make use of the Uno board by copying the work.

You will need:

Arduino board (anything you have, even a copy one).

10 kOhm resistor.

Two female plugs for audio in and audio out.

Neopixel led strip. Mine is 1 meter long and has got 30 led's.

Optional

Case (printable files in project)

Prototype shield. Just to keep everything nice looking.

Step 2: Desing

The case was designed with Tinkercad. Simple and easy to use tool that works in your browser.

Check that out for some easy 3D designs.

Step 3: Printing

The case was printed with Printrbot makers kit. Basic and cheap printer.

Settings for printer was 0.4mm nozzle, 0.2mm layer height, 40mm/s print speed.

Holes for the case are made in the printing. If the fit is snug in the holes just use file to make it fit.

Step 4: Testing and Coding

The connections are pretty simple.

Put a resistor between GND and A0 to make the analog 0 by default. This helps Arduino to sense real thing and not just some interference made by radio signals etc.

Ground the ground from the plug to make it a part of Arduino.

Put left or right channel from the plug to Arduino A0

Put the led strip's +5 to VCC and GND to GND. Data cable goes to Arduino pin 6.

If you have any questions, just ask.

Note that you will need NeoPixel.h library. Find it from GitHub.

#include <Adafruit_NeoPixel.h>
#include <avr/power.h>
#define PIN 6
Adafruit_NeoPixel strip = Adafruit_NeoPixel(30, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
  
  Serial.begin(9600);
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
}
void loop() {
  
  int sensorValue = analogRead(A0);
 
  Serial.println(sensorValue);//Just for the calipration
  
 
  if(sensorValue > 10)
  {
rainbowCycle(0); 
}
if(sensorValue >30){
theaterChase(strip.Color(255,0,0),10);
theaterChase(strip.Color(255,0,0),10); 
theaterChase(strip.Color(0,0,255),10); 
}
if(sensorValue >40){
  colorWipe(strip.Color(255,0,0),10); 
  colorWipe(strip.Color(0,255,0),10); 
  colorWipe(strip.Color(0,0,255),10); 
}
}
//this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait) {
  uint16_t i, j;
  for(j=0; j<256*1; j++) { // 1 cycle of all colors on wheel
    for(i=0; i< strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
    }
    strip.show();
    delay(wait);
  }
}
//Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
  for (int j=0; j<5; j++) {  //do 5 cycles of chasing
    for (int q=0; q < 3; q++) {
      for (int i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, c);    //turn every third pixel on
      }
      strip.show();
     
      delay(wait);
     
      for (int i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }
}
// Fill the dots one after the other with a color
void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i

koodi.ino
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Step 5: Test Fit

Solder pins to the shield if you use one.

Drop the Arduino in to the case to see it fits.

If it fits continue to next step.

If you use different Arduino than Uno. (Smaller or bigger does not matter.)

And need a design for the case. I can make one on my free time and send it to you via email. Unfortunately i really can't make the real print and send it to you because sending something from here Finland to some other country is really expensive.