Membuat Lampu LED Mengikuti Irama Musik

Pernah melihat konser yang dipenuhi dengan berbagai lampu ? dan Lampunya berkedap kedip sesuai dengan irama musik yang ditampilkan. 

Arduino sebagai base utama, menggunakan FFT Library untuk mendecode suara ke dalam oktaf, kemudian Fastled library untuk memberikan informasi ke Led Strip.

Nah, Kali ini kita akan mencoba untuk membuatnya. Berikut bahan-bahan dan resepnya :

Komponen Hardware:

1. Arduino Nano R3
2. LED Strip
3. Max 4466 Amplifier
4. Potensiometer 10K Ohm

1. Power Supply 12 V 1.5 A
2. 5V DC-DC Converter

#include "FastLED.h"

// How many leds in your strip?
#include 


#define OCTAVE 1 //   // Group buckets into octaves  (use the log output function LOG_OUT 1)
#define OCT_NORM 0 // Don't normalise octave intensities by number of bins
#define FHT_N 256 // set to 256 point fht
#include  // include the library
//int noise[] = {204,188,68,73,150,98,88,68}; // noise level determined by playing pink noise and seeing levels [trial and error]{204,188,68,73,150,98,88,68}


// int noise[] = {204,190,108,85,65,65,55,60}; // noise for mega adk
//int noise[] = {204,195,100,90,85,80,75,75}; // noise for NANO
int noise[] = {204,198,100,85,85,80,80,80};
float noise_fact[] = {15, 7, 1.5, 1, 1.2, 1.4, 1.7,3}; // noise level determined by playing pink noise and seeing levels [trial and error]{204,188,68,73,150,98,88,68}
float noise_fact_adj[] = {15, 7, 1.5, 1, 1.2, 1.4, 1.7,3}; // noise level determined by playing pink noise and seeing levels [trial and error]{204,188,68,73,150,98,88,68}


#define LED_PIN     5
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB


// Params for width and height
const uint8_t kMatrixWidth = 11;
const uint8_t kMatrixHeight = 27;
 #define NUM_LEDS (kMatrixWidth * kMatrixHeight)
//#define NUM_LEDS    15

CRGB leds[NUM_LEDS];

int counter2=0;



void setup() { 
//  Serial.begin(115200);
  delay(1000);
  FastLED.addLeds(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
  
  FastLED.setBrightness (200);
  fill_solid(leds, NUM_LEDS, CRGB::Black); 
  FastLED.show();    
// TIMSK0 = 0; // turn off timer0 for lower jitter
  ADCSRA = 0xe5; // set the adc to free running mode
  ADMUX = 0x40; // use adc0
  DIDR0 = 0x01; // turn off the digital input for adc0

}




void loop() { 
int prev_j[8];
int beat=0;
int prev_oct_j;
int counter=0;
int prev_beat=0;
int led_index=0;
int saturation=0;
int saturation_prev=0;
int brightness=0;
int brightness_prev=0;

 while (1) { // reduces jitter

      cli();  // UDRE interrupt slows this way down on arduino1.0
     
  for (int i = 0 ; i < FHT_N ; i++) { // save 256 samples
      while (!(ADCSRA & 0x10)); // wait for adc to be ready
      ADCSRA = 0xf5; // restart adc
      byte m = ADCL; // fetch adc data
      byte j = ADCH;
      int k = (j << 8) | m; // form into an int
      k -= 0x0200; // form into a signed int
      k <<= 6; // form into a 16b signed int
      fht_input[i] = k; // put real data into bins
    }
    fht_window(); // window the data for better frequency response
    fht_reorder(); // reorder the data before doing the fht
    fht_run(); // process the data in the fht
    fht_mag_octave(); // take the output of the fht  fht_mag_log()

   // every 50th loop, adjust the volume accourding to the value on A2 (Pot)
    if (counter >= 50) {
      ADMUX = 0x40 | (1 & 0x07); // set admux to look at Analogpin A1 - Master Volume
 

      while (!(ADCSRA & 0x10)); // wait for adc to be ready
      ADCSRA = 0xf5; // restart adc 
  delay(10);      
      while (!(ADCSRA & 0x10)); // wait for adc to be ready
      ADCSRA = 0xf5; // restart adc 
      byte m = ADCL; // fetch adc data
      byte j = ADCH;
      int k = (j << 8) | m; // form into an int
      float master_volume=(k+0.1)/1000 +.5;  // so the valu will be between ~0.5 and 1.5
 // Serial.println (master_volume);


      for (int i=1; i<8; i++) {
          noise_fact_adj[i]=noise_fact[i]*master_volume;
      }

      ADMUX = 0x40 | (0 & 0x07); // set admux back to look at A0 analog pin (to read the microphone input
      counter = 0;
    }
        
    sei();
    counter++;
 
     
    // End of Fourier Transform code - output is stored in fht_oct_out[i].

    // i=0-7 frequency (octave) bins (don't use 0 or 1), fht_oct_out[1]= amplitude of frequency for bin 1
    // for loop a) removes background noise average and takes absolute value b) low / high pass filter as still very noisy
    // c) maps amplitude of octave to a colour between blue and red d) sets pixel colour to amplitude of each frequency (octave)
 
    for (int i = 1; i < 8; i++) {  // goes through each octave. skip the first 1, which is not useful

      int j;      
      j = (fht_oct_out[i] - noise[i]); // take the pink noise average level out, take the asbolute value to avoid negative numbers
      if (j<10) {j=0;}  
      j= j*noise_fact_adj[i];
       
      if (j<10) {j=0;}
      else {  
        j= j*noise_fact_adj[i];
        if (j>180) {
          if (i>=7) {
            beat+=2;
          }
          else {
            beat+=1;
          }
        }
        j=j/30;
        j=j*30; // (force it to more discrete values)
      }
      
      prev_j[i]=j;

//     Serial.print(j);
//     Serial.print(" "); 

 
// this fills in 11 LED's with interpolated values between each of the 8 OCT values 
       if (i>=2) {
        led_index=2*i-3;
        prev_oct_j=(j+prev_j[i-1])/2;
        
        saturation=constrain(j+30, 0,255);
        saturation_prev=constrain(prev_oct_j+30, 0,255);
        brightness=constrain(j, 0,255);
        brightness_prev=constrain(prev_oct_j, 0,255);
if (brightness==255) {
  saturation=50;
  brightness=200;
}
if (brightness_prev==255) {
  saturation_prev=50;
  brightness_prev=200;
}


        for (uint8_t y=0;y2){         
            prev_oct_j=(j+prev_j[i-1])/2;
            leds[ XY(led_index-2,y)]=CHSV(prev_oct_j+y*30,saturation_prev, brightness_prev);             
          }              
        }
       }
    }
      


      if (beat>=7) {
          fill_solid(leds, NUM_LEDS, CRGB::Gray);          
          FastLED.setBrightness(120);


 //    FastLED.setBrightness(200);

      }                 
    else {
      if (prev_beat!=beat) {
        FastLED.setBrightness(40+beat*beat*5);
        prev_beat=beat;
      }

    }

    FastLED.show(); 
    if (beat) {
      counter2+=((beat+4)/2-2);
      if (counter2<0) {counter2=1000;}
      if (beat>3 && beat<7) {
         FastLED.delay (20);
      }
      beat=0;
    }

// Serial.println();
 }
}



// Param for different pixel layouts
const bool    kMatrixSerpentineLayout = true;
// Set 'kMatrixSerpentineLayout' to false if your pixels are 
// laid out all running the same way, like this:

// Set 'kMatrixSerpentineLayout' to true if your pixels are 
// laid out back-and-forth, like this:

uint16_t XY( uint8_t x, uint8_t y)
{
  uint16_t i;
  
  if( kMatrixSerpentineLayout == false) {
    i = (y * kMatrixWidth) + x;
  }

  if( kMatrixSerpentineLayout == true) {
    if( y & 0x01) {
      // Odd rows run backwards
      uint8_t reverseX = (kMatrixWidth - 1) - x;
      i = (y * kMatrixWidth) + reverseX;

    } else {
      // Even rows run forwards
      i = (y * kMatrixWidth) + x;

    }
  }
  
  i=(i+counter2)%NUM_LEDS;  
  return i;
}