simple breath effect

#include "FastLED.h"

// LEDs pin
#define DATA_PIN 3

// LED brightness
#define BRIGHTNESS 240

#define NUM_LEDS 30

// Define the array of leds
CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
}

void loop() {
#define MIN_BRIGHTNESS 50
#define MAX_BRIGHTNESS BRIGHTNESS
#define HUE_COLOR 0    // red color
#define SPEED_FADE 15    //speed of effect

int  a = millis();
 byte b = triwave8 (a/SPEED_FADE);

       byte breath = ease8InOutCubic (b);
        breath = map (breath,0,255, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
        fill_solid(leds, NUM_LEDS, CHSV(HUE_COLOR, 255, breath));
      //fill_gradient(leds,NUM_LEDS,CHSV(0,255,MIN_BRIGHTNESS),CHSV(0,255,breath), CHSV(0,255,breath), CHSV(0,255,MIN_BRIGHTNESS),LONGEST_HUES);  // uncomment this to smooth gradient looking effect

        adjust_gamma();

  FastLED.delay(50);

}



void adjust_gamma()   // https://www.reddit.com/r/FastLED/comments/b2mlvf/gamma_correction/eity0u1?utm_source=share&utm_medium=web2x
                     // Marc Millers simple gamma correction

 {
  for (uint16_t i = 0; i < NUM_LEDS; i++)
  {
    leds[i].r = dim8_video(leds[i].r);
    leds[i].g = dim8_video(leds[i].g);
    leds[i].b = dim8_video(leds[i].b);
  }
}