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This is a LED light Organ project meant for summertime evening fun.

 

Imagine grilling on your house deck, patio, or beachfront..........relaxing (or rockin' and rollin' ) with a stereo playing,

and 100+ feet (35 meters) of deck railing ( backyard fence or yard ) bursting in a multitude of LED colors to the tunes,

lighting up the night sky.

 

That is the goal of this project.....just watch :-)

 

https://youtu.be/NHUzB_AjNY0

 

5M LED strips are relatively inexpensive, wickedly bright , can be bought in a wide variety of colors and in waterproof versions.

 

So here we go on how it works:

 

The MSGEQ7 graphic equalizer IC inputs mono audio signal ( a stereo input jack is used and sums the left and right side together) , sorts out the audio into 7 different frequency bands, and provides an analog output of the the amplitude of the selected frequency band.

This output band desired is selected by the Arduino, and the MSGEQ7 analog output read by the Arduino.

The Arduino compares the analog input level to a threshold setting, if the amplitude exceeds the threshold, the output turns on the MOSFET, driving the LED bank. The 7 band scan scan is so fast, the process appears continuous.

The Arduino can sweep thru the 7 channels so fast, there are some delays intentionally set for the MSGEQ chip read/write timing.

 

The number of LED banks that can be used (power limit) is dependent on the 12V power supply, MOSFET current, and wire size of the power circuit.

This can get really big as is , and even bigger with little change and no sweat. 

 

Note the pushbutton for test mode, that can be activated at any time. It is very helpful in troubleshooting, or just putting on a short light show itself.

 

short Video of the LED Light Organ using a 20Hz-20kHz audio test file played by ipod

https://youtu.be/gk0YhrchxXU

 

short Video of the LED Light Organ using an example audio test file played by ipod

https://youtu.be/QiQ49bj-sWE

 

Code:

/*

 

  Test 3 is based on Test2Working is showing the MSWGEQ7 is reading an analog input from a ipod earphone jack, and providing volts from the multiplexor.

  -> added pot to analog input 1 for threshold adjust on LED trigger

  -> add a PB to D6 to run a test routine that strobes the lights

 

  control interface to MSGEQ7 IC

  strobe control for equalizer bands, read in multiplexed voltage per band, drive outputs LEDs

 

  Arduino D4 wires to MSGEQ7 pin 4 strobe

  Arduino D5 wires to MSGEQ7 pin 7 reset

 

  all ins have pull ups

 

  Arduino D7 = 63Hz LED , LOW = ON

  Arduino D8 = 160Hz LED

  Arduino D9 = 400Hz LED

  Arduino D10 = 1kHz LED

  Arduino D11 = 2.5 kHz LED

  Arduino D12 = 6kHz LED

  Arduino D13 = 16kHz LED

 

  Arduino A0 wires to MSGEQ7 pin 3 Vout

 

*/

int BandMagnitude[8];

int Vin =0 ;

int LEDThreshold = 500;

int strobeBit=1;

int pausetime =1000;

 

 

// the setup function runs once when you press reset or power the board

void setup()

{

  Serial.begin(9600);          //  setup serial

 

  // initialize digital output pins for LEDS.

  pinMode(13, OUTPUT);

  pinMode(12, OUTPUT);

  pinMode(11, OUTPUT);

  pinMode(10, OUTPUT);

  pinMode(9, OUTPUT);

  pinMode(8, OUTPUT);

  pinMode(7, OUTPUT);

 

  // initialize digital output pins for strobe and reset MSGEQ7

    pinMode(5, OUTPUT); //reset MSGEQ7 WHEN HIGH, LOW enables STROBE

    pinMode(4, OUTPUT); //strobe MSGEQ7 output, edge triggered LOW is active state for strobe

 

 

// defines and intehger array for the 7 band values, array location 0 is unused

 

 

   pinMode(6, INPUT_PULLUP); //tie pin D6 to ground to run the strobe LED routine

 

int BandMagnitude[8];

int Vin =0 ;

}

 

 

// the loop function runs over and over again forever

void loop()

 

 

{

  // initialze the strobe and reset after every scan to ensure synchronization

 

    initializeMSGEQ7 ();

    //delay (1);

     delayMicroseconds(100); // minimum delay is 72 usec for strobe reset

     LEDThreshold = analogRead(1) ;

 

    for (int i=1; i <= 7; i++)

     {

       digitalWrite(4, LOW);   // strobe is edge trigger LOW active

        delayMicroseconds(30); // minimum delay is 18 usec for strobe reset

      // delay (1);

       Vin = analogRead(0) ;

      BandMagnitude[i] = Vin ;

       digitalWrite(4, HIGH);   // strobe off,  strobe is edge trigger LOW active

//          Serial.println("BandMagnitude[i] =");             // debug value

//          Serial.println(BandMagnitude[i]);             // debug value

  //         Serial.println("[i] =");             // debug value

  //         Serial.println(i);             // debug value

       if (BandMagnitude[i]>LEDThreshold)

          { digitalWrite((6+i), LOW); }

       if (BandMagnitude[i]<LEDThreshold)  {digitalWrite((6+i), HIGH);}

    

           delayMicroseconds(30); // minimum delay is 18 usec for strobe reset

   //    delay (90); // delay time with strobe low for the next read cycle

 

}

strobeBit = digitalRead(6);

if (strobeBit == LOW) { strobe();}

//          Serial.println("BandMagnitude[i] =");             // debug value

          Serial.println("[strobebit] =");             // debug value

           Serial.println(strobeBit);

 

 

}

 

 

void initializeMSGEQ7 ()

{

   digitalWrite(5, HIGH);   // make RESET line HIGH

   digitalWrite(4, HIGH);   // turn on strobe bit

  delayMicroseconds(30); // minimum delay is 18 usec for strobe width

  digitalWrite(4, LOW);   // turn off strobe bit

   delayMicroseconds(1); // minimum delay is 100 ns

//   delay(1);

  digitalWrite(4, HIGH);   // turn off strobe bit

//  delay(1);

   digitalWrite(5, LOW);   // make RESET line LOW to enable the strobe line

delayMicroseconds(100); // minimum delay is 72 usec for strobe reset

// digitalWrite(5, LOW);   // make RESET line LOW to enable the strobe line

// delay (1);

//  digitalWrite(4, HIGH);   // turn off strobe bit (low is active)

// delay(1);

}

 

 

void strobe ()

{ pausetime=500;

   for (int j=1; j <= 15; j++)

   {

      pausetime=(pausetime/2);

       if (pausetime<8){pausetime=8;}

         for (int i=1; i <= 7; i++)

            { digitalWrite((6+i), LOW);

             delay (pausetime);

             digitalWrite((6+i), HIGH);

             delay (5);

            }

         for (int i=0; i <= 7; i++)

           { digitalWrite((12-i), LOW);

             delay (pausetime);

              digitalWrite((12-i), HIGH);

             delay (5);

             }

      }

   }