rainbow_brightness_and_saturation.ino

//***************************************************************
//  Example of changing the brightness and saturation of
//  FastLED's fill_rainbow, which by default fills pixels with
//  the rainbow at full brightness and full saturation.
//
//  Marc Miller, Sept 2018
//***************************************************************

#include "FastLED.h"
#define NUM_LEDS 12
CRGB leds[NUM_LEDS];

uint8_t V;  //brightness for rainbow
uint8_t S;  //saturation for rainbow
boolean toggleS;
boolean toggleV;

//Amount to tint (desaturate) rainbow.  Can use either RGB or HSV format
//CRGB tintAmt(128,128,128);
CHSV tintAmt(0,0,90);


//---------------------------------------------------------------
void setup() { 
  FastLED.addLeds<NEOPIXEL, 11>(leds, NUM_LEDS);
  FastLED.setBrightness(255);
}

//---------------------------------------------------------------
void loop()
{
  fill_rainbow(leds, NUM_LEDS, millis()/100);  //fill strip with moving rainbow

  EVERY_N_SECONDS(5) { toggleS = !toggleS; }  //toggle Saturation (ie. "tint")
  EVERY_N_SECONDS(30) { toggleV = !toggleV; }  //toggle Value (brightness)

  if (toggleS) {
    for (uint8_t i=0; i<NUM_LEDS; i++) {
      leds[i] += tintAmt;
    }
  } else {
    //No tint added
  }

  if (toggleV) {
    V = 128;  //fade down by V/256
    fadeToBlackBy( leds, NUM_LEDS, V);  //fade by value V
  } else {
    V = 0;  //no fade
  }

  FastLED.show();

}