Анализатор спектра на матрице 8x8 MAX7219

////////// |PORT   |pin | Arduino 
// MAX7219
#define CLK PD2 // | 4  | D2
#define CS  PD3 // | 5  | D3
#define DIN PD4 // | 6  | D4

#define AUTO_GAIN 1        // автонастройка по громкости
#define LOW_PASS 40        // нижний порог чувствительности шумов (нет скачков при отсутствии звука)
#define DEF_GAIN 300       // максимальный порог по умолчанию 
#define FHT_N 256          // ширина спектра х2
#define LOG_OUT 1
#define INPUT_GAIN 1.0 
#define BR 0               // яркость

#include <FHT.h>  // http://forum.rcl-radio.ru/misc.php?action=pan_download&item=297&download=1
byte posOffset[32] = {4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,21,22,23,24,25,26,27,28,29,30,31,32,33,34};

int i1;
unsigned long data[32];
unsigned long data1,data2,data3,data4,data5,data6,data7,data8;
byte a[32];
int ur[32],urr[32];
unsigned long gainTimer;
int gain_sp = DEF_GAIN; 
int maxValue; 
int maxValue_f;
float k = 0.5; 


void setup(){
   ADMUX  = 0b11000000; ADCSRA = 0b11010110;
  DDRD |= (1 << DIN) | (1 << CS) | (1 << CLK);
  max7219_L(0x0F, 0);// тест выкл.
  max7219_L(0x0C, 0x01010101);// вкл. индик.
  max7219_L(0x0A, 0x01010101*BR);// яркость
  max7219_L(0x09, 0);// дешифраторы выкл.
  max7219_L(0x0B, 0x07070707);// кол-во разрядов 
  }

void loop(){

  analyzeAudio();

      for (int i = 0; i < FHT_N/2; i++) {                     
      if (fht_log_out[i] < LOW_PASS) fht_log_out[i] = 0;
      fht_log_out[i] = (float)fht_log_out[i] * INPUT_GAIN;}

       maxValue = 0;
      for (int pos = 0; pos < 32; pos++) {  
        if (fht_log_out[posOffset[pos]] > maxValue) maxValue = fht_log_out[posOffset[pos]];
        int posLevel = map(fht_log_out[posOffset[pos]], LOW_PASS, gain_sp, 0, 8);posLevel = constrain(posLevel, 0, 8);
        
        urr[pos] = posLevel;
        if(urr[pos]<ur[pos]){ur[pos]=ur[pos]-1;}
        else{ur[pos] = posLevel;}
        delayMicroseconds(10);
        

  switch(ur[pos]){
    case 0: a[pos]=0b00000000;break;
    case 1: a[pos]=0b00000001;break;
    case 2: a[pos]=0b00000011;break;
    case 3: a[pos]=0b00000111;break;
    case 4: a[pos]=0b00001111;break;
    case 5: a[pos]=0b00011111;break;
    case 6: a[pos]=0b00111111;break;
    case 7: a[pos]=0b01111111;break;
    case 8: a[pos]=0b11111111;break;
    }
     data1 = data1 +  ((uint32_t(a[pos] >> 0) & 1)<<pos);
     data2 = data2 +  ((uint32_t(a[pos] >> 1) & 1)<<pos);
     data3 = data3 +  ((uint32_t(a[pos] >> 2) & 1)<<pos);
     data4 = data4 +  ((uint32_t(a[pos] >> 3) & 1)<<pos);
     data5 = data5 +  ((uint32_t(a[pos] >> 4) & 1)<<pos);
     data6 = data6 +  ((uint32_t(a[pos] >> 5) & 1)<<pos);
     data7 = data7 +  ((uint32_t(a[pos] >> 6) & 1)<<pos);
     data8 = data8 +  ((uint32_t(a[pos] >> 7) & 1)<<pos);
      }
      
 max7219_L(8, data8 );
 max7219_L(7, data7  );
 max7219_L(6, data6  );
 max7219_L(5, data5  );
 max7219_L(4, data4  );
 max7219_L(3, data3  );
 max7219_L(2, data2  );
 max7219_L(1, data1  );
  data1=0;data2=0;data3=0;data4=0;data5=0;data6=0;data7=0;data8=0;
 

  if (AUTO_GAIN) {
    if (millis() - gainTimer > 10) {      
      maxValue_f = maxValue * k + maxValue_f * (1 - k);
      if (maxValue_f > LOW_PASS) gain_sp = maxValue_f;
       else gain_sp = DEF_GAIN;
       gainTimer = millis();}}
    }

void max7219_L(byte reg_n, unsigned long h){
  byte h1 = h >> 24;
  byte h2 = h >> 16;
  byte h3 = h >> 8;
  byte h4 = h;
  PORTD &=~(1 << CS);WriteBit16(reg_n,h1);WriteBit16(reg_n,h2);WriteBit16(reg_n,h3);WriteBit16(reg_n,h4);PORTD |=(1 << CS);
  }   

void WriteBit16(byte reg, byte data){  
     for(char i = 7; i >= 0; i--){
        PORTD &= ~(1 << CLK);
        if(((reg >> i) & 1) == 1){PORTD |= (1 << DIN);}else{PORTD &= ~(1 << DIN);}
        PORTD |=(1 << CLK);}
     for(char i = 7; i >= 0; i--){
        PORTD &= ~(1 << CLK);
        if(((data >> i) & 1) == 1){PORTD |= (1 << DIN);}else{PORTD &= ~(1 << DIN);}
        PORTD |=(1 << CLK);}
        PORTD &= ~(1 << CLK);PORTD |= (1 << DIN);
  } 

void analyzeAudio() { 
 while(i1 < FHT_N){i1++; 
    do{ADCSRA |= (1 << ADSC);} 
    while((ADCSRA & (1 << ADIF)) == 0);fht_input[i1] = (ADCL|ADCH << 8);}i1=0;
    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_log(); // take the output of the fht
}