【雕爷学编程】Arduino动手做（149）---MAX9814咪头传感器模块5 中等

/*
  【Arduino】168种传感器模块系列实验（资料代码 +图形编程 +仿真编程）
  实验一百四十六：64位WS2812B 8 * 8 xRGB 5050 LED模块 ws2812s像素点阵屏
  项目四十一：六十四位音乐频谱灯十六位音乐反应动态频谱灯
*/

#include "FastLED.h"

#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 <FHT.h> // 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     6
#define LED_TYPE    WS2812
#define COLOR_ORDER GRB


// Params for width and height
const uint8_t kMatrixWidth = 8;
const uint8_t kMatrixHeight = 8;//----------was 27
//#define NUM_LEDS (kMatrixWidth * kMatrixHeight)
#define NUM_LEDS    64

CRGB leds[NUM_LEDS];

int counter2 = 0;



void setup() {
  Serial.begin(9600);
  delay(1000);
  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );

  FastLED.setBrightness (33);
  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 + .75; // so the valu will be between ~0.5 and 1.---------------------+.75 was .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 + 50, 0, 255); //-----------50 was 30
        saturation_prev = constrain(prev_oct_j + 50, 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; y < kMatrixHeight; y++) {
          leds[XY(led_index - 1, y)] = CHSV(j + y * 30, saturation, brightness);
          if (i > 2) {
            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(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 = false;
// 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;
}

/*

 【Arduino】168种传感器模块系列实验（资料代码+仿真编程+图形编程）

  实验一百四十九：MAX9814麦克风放大器模块 MIC话筒声音放大/咪头传感器

  项目四十二：快速哈特利变换FHT音乐反应灯条

*/

/*

 这是带有 FastLED 的 FHT 库的项目

 FHT 库位于 http://wiki.openmusiclabs.com/wiki/ArduinoFHT

 开始的例子是：

 https://github.com/TJC/arduino/blob/master/fhttest/fhttest.cpp

 注意：如果您使用的是由 3.3V 信号供电的麦克风，例如 Sparkfun MEMS 麦克风，则将 3.3V 连接到 AREF 引脚。

 还要确保取消对 analogReference(EXTERNAL); 的注释。 在设置（）中。

 在线频率发生器 测试：http://onlinetonegenerator.com/frequency-sweep-generator.html

*/

#define qsubd(x, b) ((x>b)?wavebright:0)           // A digital unsigned subtraction macro. if result <0, then => 0. Otherwise, take on fixed value.

#define qsuba(x, b) ((x>b)?x-b:0)              // Unsigned subtraction macro. if result <0, then => 0.

#define wavebright 128                    // qsubd result will be this value if subtraction is >0.

#include "FastLED.h"                     // FastLED library. Preferably the latest copy of FastLED 2.1.

#if FASTLED_VERSION < 3001000

#error "Requires FastLED 3.1 or later; check github for latest code."

#endif

// Fixed definitions cannot change on the fly.

#define LED_DT 6                       // Data pin to connect to the strip.

//#define LED_CK 11                       // Clock pin for APA102 or WS2801

#define COLOR_ORDER GRB                    // It's GRB for WS2812

#define LED_TYPE WS2812B                    // What kind of strip are you using (APA102, WS2801 or WS2812B)

#define NUM_LEDS 16                    // Number of LED's.

// Initialize changeable global variables.

uint8_t max_bright = 255;                   // Overall brightness definition. It can be changed on the fly.

struct CRGB leds[NUM_LEDS];                  // Initialize our LED array.

#define LOG_OUT 1

#define FHT_N 256                       // Set to 256 point fht.

#define inputPin A0

//#define potPin A4

#include <FHT.h>                       // FHT library

uint8_t hueinc = 0;                        // A hue increment value to make it rotate a bit.

uint8_t micmult = 25;

uint8_t fadetime = 900;

uint8_t noiseval = 25;                    // Increase this to reduce sensitivity. 30 seems best for quiet

void setup() {

 analogReference(EXTERNAL);                 // Connect 3.3V to AREF pin for any microphones using 3.3V

 Serial.begin(9600);                    // use the serial port

 LEDS.addLeds<LED_TYPE, LED_DT, COLOR_ORDER>(leds, NUM_LEDS);

 // LEDS.addLeds<LED_TYPE, LED_DT, LED_CK, COLOR_ORDER>(leds, NUM_LEDS);

 FastLED.setBrightness(max_bright);

 set_max_power_in_volts_and_milliamps(5, 500);        // FastLED Power management set at 5V, 500mA.

}

void loop() {

 //  noiseval = map(analogRead(potPin), 0, 1023, 16, 48);     // Adjust sensitivity of cutoff.

 EVERY_N_MILLISECONDS(13) {

  fhtsound();

 }

 show_at_max_brightness_for_power();

 Serial.println(LEDS.getFPS(), DEC);     // Display frames per second on the serial monitor.

 Serial.println(" ");     // Display frames per second on the serial monitor.

 Serial.println(analogRead(inputPin));    // print as an ASCII-encoded decimal     */

}

void fhtsound() {

 // hueinc++;                          // A cute little hue incrementer.

 GetFHT();                          // Let's take FHT_N samples and crunch 'em.

 for (int i = 0; i < NUM_LEDS; i++) {            // Run through the LED array.

  int tmp = qsuba(fht_log_out[2 * i + 2], noiseval);    // Get the sample and subtract the 'quiet' normalized values, but don't go < 0.

  if (tmp > (leds[i].r + leds[i].g + leds[i].b) / 2)     // Refresh an LED only when the intensity is low

   leds[i] = CHSV((i * 4) + tmp * micmult, 255, tmp * micmult); // Note how we really cranked up the tmp value to get BRIGHT LED's. Also increment the hue for fun.

  leds[i].nscale8(fadetime);                   // Let's fade the whole thing over time as well.

 }

} // fhtsound()

void GetFHT() {

 cli();

 for (int i = 0 ; i < FHT_N ; i++) fht_input[i] = analogRead(inputPin);

 sei();

 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();

} // GetFHT()

/*

【Arduino】168种传感器模块系列实验（资料代码+仿真编程+图形编程）

  实验一百四十九：MAX9814麦克风放大器模块 MIC话筒声音放大/咪头传感器

   项目四十三：快速哈特利变换FHT音乐反应64位灯板

*/

/*

 这是带有 FastLED 的 FHT 库的项目

 FHT 库位于 http://wiki.openmusiclabs.com/wiki/ArduinoFHT

 开始的例子是：

 https://github.com/TJC/arduino/blob/master/fhttest/fhttest.cpp

 注意：如果您使用的是由 3.3V 信号供电的麦克风，例如 Sparkfun MEMS 麦克风，则将 3.3V 连接到 AREF 引脚。

 还要确保取消对 analogReference(EXTERNAL); 的注释。 在设置（）中。

 在线频率发生器 测试：http://onlinetonegenerator.com/frequency-sweep-generator.html

*/

#define qsubd(x, b) ((x>b)?wavebright:0)           // A digital unsigned subtraction macro. if result <0, then => 0. Otherwise, take on fixed value.

#define qsuba(x, b) ((x>b)?x-b:0)              // Unsigned subtraction macro. if result <0, then => 0.

#define wavebright 128                    // qsubd result will be this value if subtraction is >0.

#include "FastLED.h"                     // FastLED library. Preferably the latest copy of FastLED 2.1.

#if FASTLED_VERSION < 3001000

#error "Requires FastLED 3.1 or later; check github for latest code."

#endif

// Fixed definitions cannot change on the fly.

#define LED_DT 6                       // Data pin to connect to the strip.

//#define LED_CK 11                       // Clock pin for APA102 or WS2801

#define COLOR_ORDER GRB                    // It's GRB for WS2812

#define LED_TYPE WS2812B                    // What kind of strip are you using (APA102, WS2801 or WS2812B)

#define NUM_LEDS 64                    // Number of LED's.

// Initialize changeable global variables.

uint8_t max_bright = 255;                   // Overall brightness definition. It can be changed on the fly.

struct CRGB leds[NUM_LEDS];                  // Initialize our LED array.

#define LOG_OUT 1

#define FHT_N 256                       // Set to 256 point fht.

#define inputPin A0

//#define potPin A4

#include <FHT.h>                       // FHT library

uint8_t hueinc = 0;                        // A hue increment value to make it rotate a bit.

uint8_t micmult = 25;

uint8_t fadetime = 900;

uint8_t noiseval = 25;                    // Increase this to reduce sensitivity. 30 seems best for quiet

void setup() {

 analogReference(EXTERNAL);                 // Connect 3.3V to AREF pin for any microphones using 3.3V

 Serial.begin(9600);                    // use the serial port

 LEDS.addLeds<LED_TYPE, LED_DT, COLOR_ORDER>(leds, NUM_LEDS);

 // LEDS.addLeds<LED_TYPE, LED_DT, LED_CK, COLOR_ORDER>(leds, NUM_LEDS);

 FastLED.setBrightness(max_bright);

 set_max_power_in_volts_and_milliamps(5, 500);        // FastLED Power management set at 5V, 500mA.

}

void loop() {

 //  noiseval = map(analogRead(potPin), 0, 1023, 16, 48);     // Adjust sensitivity of cutoff.

 EVERY_N_MILLISECONDS(13) {

  fhtsound();

 }

 show_at_max_brightness_for_power();

 Serial.println(LEDS.getFPS(), DEC);     // Display frames per second on the serial monitor.

 Serial.println(" ");     // Display frames per second on the serial monitor.

 Serial.println(analogRead(inputPin));    // print as an ASCII-encoded decimal     */

}

void fhtsound() {

 // hueinc++;                          // A cute little hue incrementer.

 GetFHT();                          // Let's take FHT_N samples and crunch 'em.

 for (int i = 0; i < NUM_LEDS; i++) {            // Run through the LED array.

  int tmp = qsuba(fht_log_out[2 * i + 2], noiseval);    // Get the sample and subtract the 'quiet' normalized values, but don't go < 0.

  if (tmp > (leds[i].r + leds[i].g + leds[i].b) / 2)     // Refresh an LED only when the intensity is low

   leds[i] = CHSV((i * 4) + tmp * micmult, 255, tmp * micmult); // Note how we really cranked up the tmp value to get BRIGHT LED's. Also increment the hue for fun.

  leds[i].nscale8(fadetime);                   // Let's fade the whole thing over time as well.

 }

} // fhtsound()

void GetFHT() {

 cli();

 for (int i = 0 ; i < FHT_N ; i++) fht_input[i] = analogRead(inputPin);

 sei();

 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();

} // GetFHT()

/*

【Arduino】168种传感器模块系列实验（资料代码+仿真编程+图形编程）

  实验一百四十九：MAX9814麦克风放大器模块 MIC话筒声音放大/咪头传感器

 项目四十四：Adafruit_NeoPixel音乐节奏灯板

*/

#include <Adafruit_NeoPixel.h>

#include <math.h>

#define N_PIXELS 64

#define MIC_PIN  A0

#define LED_PIN  6

#define SAMPLE_WINDOW  5

#define PEAK_HANG 24

#define PEAK_FALL 4

#define INPUT_FLOOR 10

#define INPUT_CEILING 50

byte peak = 16;

unsigned int sample;

byte Count = 0;

byte HangCount = 0;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_PIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);

void setup() {

 Serial.begin(9600);

 analogReference(EXTERNAL);

 strip.setBrightness(22);

 strip.show();

 strip.begin();

}

float fscale( float originalMin, float originalMax, float newBegin, float newEnd, float inputValue, float curve) {

 float OriginalRange = 0;

 float NewRange = 0;

 float zeroRefCurVal = 0;

 float normalizedCurVal = 0;

 float rangedValue = 0;

 boolean invFlag = 0;

 if (curve > 10) curve = 10;

 if (curve < -10) curve = -10;

 curve = (curve * -.1) ;

 curve = pow(10, curve);

 if (inputValue < originalMin) {

  inputValue = originalMin;

 }

 if (inputValue > originalMax) {

  inputValue = originalMax;

 }

 OriginalRange = originalMax - originalMin;

 if (newEnd > newBegin) {

  NewRange = newEnd - newBegin;

 }

 else

 {

  NewRange = newBegin - newEnd;

  invFlag = 1;

 }

 zeroRefCurVal = inputValue - originalMin;

 normalizedCurVal = zeroRefCurVal / OriginalRange;  // normalize to 0 - 1 float

 Serial.print(OriginalRange, DEC);

 Serial.print("  ");

 Serial.print(NewRange, DEC);

 Serial.print("  ");

 Serial.println(zeroRefCurVal, DEC);

 Serial.println();

 delay(10); 

 if (originalMin > originalMax ) {

  return 0;

 }

 if (invFlag == 0) {

  rangedValue = (pow(normalizedCurVal, curve) * NewRange) + newBegin;

 }

 else

 {

  rangedValue = newBegin - (pow(normalizedCurVal, curve) * NewRange);

 }

 return rangedValue;

}

void loop() {

 unsigned long startMillis = millis();

 float peakToPeak = 0;

 unsigned int signalMax = 0;

 unsigned int signalMin = 1023;

 unsigned int c, y;

 while (millis() - startMillis < SAMPLE_WINDOW)

 {

  sample = analogRead(MIC_PIN);

  if (sample < 1024)

  {

   if (sample > signalMax)

   {

    signalMax = sample;

   }

   else if (sample < signalMin)

   {

    signalMin = sample;

   }

  }

 }

 peakToPeak = signalMax - signalMin;

 for (int i = 0; i <= strip.numPixels() - 1; i++) {

  strip.setPixelColor(i, Wheel(map(i, 0, strip.numPixels() - 1, 30, 150)));

 }

 c = fscale(INPUT_FLOOR, INPUT_CEILING, strip.numPixels(), 0, peakToPeak, 2);

 if (c < peak) {

  peak = c;

  HangCount = 0;

 }

 if (c <= strip.numPixels()) {

  drawLine(strip.numPixels(), strip.numPixels() - c, strip.Color(0, 0, 0));

 }

 y = strip.numPixels() - peak;

 strip.setPixelColor(y - 1, Wheel(map(y, 0, strip.numPixels() - 1, 30, 150)));

 strip.show();

 if (HangCount > PEAK_HANG) {

  if (++Count >= PEAK_FALL) {

   peak++;

   Count = 0;

  }

 }

 else {

  HangCount++;

 }

}

void drawLine(uint8_t from, uint8_t to, uint32_t c) {

 uint8_t fromTemp;

 if (from > to) {

  fromTemp = from;

  from = to;

  to = fromTemp;

 }

 for (int i = from; i <= to; i++) {

  strip.setPixelColor(i, c);

 }

}

uint32_t Wheel(byte WheelPos) {

 if (WheelPos < 85) {

  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);

 }

 else if (WheelPos < 170) {

  WheelPos -= 85;

  return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);

 }

 else {

  WheelPos -= 170;

  return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);

 }

}

/*

【Arduino】168种传感器模块系列实验（资料代码+仿真编程+图形编程）

  实验一百四十九：MAX9814麦克风放大器模块 MIC话筒声音放大/咪头传感器

 项目四十五：动态音乐频谱仪

 接脚连线：

 MAX7219    UNO

 VCC →→→→→ 5V

 GND →→→→→ GND

 DIN →→→→→ D12（数据，数据接收引脚）

 CS  →→→→→ D11（负载，命令接收引脚）

 CLK →→→→→ D10（时钟，时钟引脚）

*/

#include "LedControl.h"

/* Led matrix - Max7219 Declared */

LedControl lc = LedControl(12, 11, 10, 1);

const int maxScale = 11;

/* Sensor - Max9812 Declared */

const int sensorPin = A4;

const int sampleWindow = 50; // 50ms = 20Hz

unsigned int sample;

unsigned long startMillis;

unsigned long timeCycle;

unsigned int signalMax = 0;

unsigned int signalMin = 1024;

unsigned char index = 0;

unsigned int peakToPeak[8];

unsigned int displayPeak[8];

unsigned int temp[8]={0,0,0,0,0,0,0,0};

unsigned int signalMaxBuff[8];

unsigned int signalMinBuff[8];

void setup() {

 // Led matrix

 lc.shutdown(0, false); // bật hiện thị

 lc.setIntensity(0, 1); // chỉnh độ sáng 

 lc.clearDisplay(0); // tắt tất cả led

 Serial.begin(9600);

}

void loop() {

 startMillis = millis();

 //peakToPeak = 0;

 signalMax = 0;

 signalMin = 1024;

  

 // Get data in 50ms

 while (millis() - startMillis < sampleWindow) {

  sample = analogRead(sensorPin);

   

  if (sample < 1024) {

   if (sample > signalMax) {

    signalMax = sample;

   }

   if (sample < signalMin) {

    signalMin = sample;

   }

  } 

  // 20Hz - 64Hz - 125Hz - 250Hz - 500Hz - 1kHz (timeCycle = 1/F)(ms)

  timeCycle = millis() - startMillis;

  if (timeCycle == 1 || timeCycle == 2 || timeCycle == 4 || timeCycle == 8 

    || timeCycle == 16 || timeCycle == 32 || timeCycle == 40 || timeCycle == 50) {

       signalMaxBuff[index] = signalMax;

       signalMinBuff[index] = signalMin;

       index = (index + 1) % 8;

       delay(1);

       //Serial.println(timeCycle);

  }

 }

 // Delete pointer to array

 index = 0;

 // Calculation after get samples

 for (int i = 0; i < 8; i++) { // i = row (led matrix)

  // sound level

  peakToPeak[i] = signalMaxBuff[i] - signalMinBuff[i];

   

  // Map 1v p-p level to the max scale of the display

  displayPeak[i] = map(peakToPeak[i], 0, 1023, 0, maxScale);

  // Show to led matrix

  displayLed(displayPeak[i], i);

   

  // Led drop down

  if (displayPeak[i] >= temp[i]) {

   temp[i] = displayPeak[i];

  }

  else {

   temp[i]--;

  }

   

  lc.setLed(0, i, temp[i], true);

  delayMicroseconds(250);

 }

  

}

void displayLed(int displayPeak, int row) {

 switch (displayPeak) {

  case 0 : lc.setRow(0, row, 0x80); break;

  case 1 : lc.setRow(0, row, 0xC0); break;

  case 2 : lc.setRow(0, row, 0xE0); break;

  case 3 : lc.setRow(0, row, 0xF0); break;

  case 4 : lc.setRow(0, row, 0xF8); break;

  case 5 : lc.setRow(0, row, 0xFC); break;

  case 6 : lc.setRow(0, row, 0xFE); break;

  case 7 : lc.setRow(0, row, 0xFF); break;

 }

}