Master with FastLED and I2C

#include <Wire.h>
#include "FastLED.h"

const byte pinData = 3;
const byte pinSEN0232 = A0;
const byte pinPotentiometerMin = A1;
const byte pinPotentiometerMax = A2;

const byte ledCount = 24;
const byte ledBrightness = 192;
struct CRGB ledRing[ledCount];
struct CRGB ledGradient[ledCount];

const int intervalPeakHold = 900;
const int intervalPeakDecay = 30;

const float EMA_a = 0.9;

const byte addressSlave = 7; // Added for I2C

CHSV gradientHueStart = CHSV(96, 255, 96);
CHSV grandientHueEnd = CHSV(0, 255, 192);

unsigned long timeSEN0232 = 0;

long dBValue = 0;
int dBValueEMA = 0;
byte dBMin = 0;
byte dBMax = 0;

int newPeak = 0;
int previousPeak = 0;
unsigned long timePeak = 0;
byte brightnessPeak = 0;
bool decay = false;

void setup()
{
  Wire.begin(); // Added for I2C
  Serial.begin(115200); // Added for I2C
  
  FastLED.addLeds<NEOPIXEL, pinData>(ledRing, ledCount);

  FastLED.setBrightness(ledBrightness);

  fill_gradient(ledGradient, 0, gradientHueStart, 23, grandientHueEnd, SHORTEST_HUES);
}

void loop()
{
  readSEN0232();

  readPotentiometers();

  if (newPeak >= previousPeak)
  {
    previousPeak = newPeak;
    timePeak = millis();
    brightnessPeak = ledBrightness;
    decay = false;
  }

  else if (!decay && (millis() - timePeak >= intervalPeakHold))
  {
    timePeak += intervalPeakHold - intervalPeakDecay;
    decay = true;
  }

  else if (decay && (millis() - timePeak > intervalPeakDecay))
  {
    if (previousPeak > 0)
    {
      previousPeak --;

      if (brightnessPeak <= 0)
      {
        brightnessPeak = 0;
      }

      else
      {
        brightnessPeak -= 16;
      }
      timePeak += intervalPeakDecay;
    }
// 
    Wire.beginTransmission(addressSlave); // Added for I2C
    Wire.write(dBValueEMA); // Added for I2C
    Wire.endTransmission(); // Added for I2C
  }

  FastLED.clear();

  for ( byte i = 0; i <= newPeak; i++)
  {
    ledRing[i] = ledGradient[i];
  }

  ledRing[previousPeak] = CHSV(0, 255, brightnessPeak);

  FastLED.show();
}

void readSEN0232()
{
  float voltageValue;

  voltageValue = analogRead(pinSEN0232) / 1024.0 * 5.0;
  dBValue = voltageValue * 50.0;

  dBValueEMA = int ((EMA_a * dBValue) + ((1 - EMA_a) * dBValueEMA)) + 0.5;

  newPeak = constrain(map(dBValueEMA, dBMin, dBMax, 0, 23), 0, 23);
  Serial.println(dBValueEMA); // Added for I2C
}

void readPotentiometers()
{
  dBMin = constrain(map(analogRead(pinPotentiometerMin), 0, 1023, 35, 60), 35, 60);
  dBMax = constrain(map(analogRead(pinPotentiometerMax), 0, 1023, 60, 130), 60, 130);
}