Arduino FastLed linear blinking animation

art.ino

#include <FastLED.h>

// change these values

#define DATA_PIN_PHOTO_1 3
#define DATA_PIN_PHOTO_2 4
#define DATA_PIN_PHOTO_3 5
#define DATA_PIN_PHOTO_4 6
#define ANIMATION_DURATION 10000
// max offset is 1
#define TICK_1_OFFSET 0.2
#define TICK_2_OFFSET 0.4
#define TICK_3_OFFSET 0.6
#define TICK_4_OFFSET 0.8
#define PHOTO_1_START_OFFSET 0
#define PHOTO_2_START_OFFSET 0.2
#define PHOTO_3_START_OFFSET 0.4
#define PHOTO_4_START_OFFSET 0.6


// do not change these values

#define TICK_TOTAL (ANIMATION_DURATION / ANIMATION_REFRESH_INTERVAL)
#define TICK_1 (TICK_TOTAL * TICK_1_OFFSET)
#define TICK_2 (TICK_TOTAL * TICK_2_OFFSET)
#define TICK_3 (TICK_TOTAL * TICK_3_OFFSET)
#define TICK_4 (TICK_TOTAL * TICK_4_OFFSET)
// do not set a value below 100 (freeze risk)
#define ANIMATION_REFRESH_INTERVAL 100


CRGB photo1[1];
CRGB photo2[1];
CRGB photo3[1];
CRGB photo4[1];


int currentTick = 0;

void setup() {
  // init logs
  Serial.begin(9600);
  while (!Serial);

  Serial.println("Setup...");
  
  // change these values depending on the led strip
  FastLED.addLeds<NEOPIXEL, DATA_PIN_PHOTO_1>(photo1, 1);
  FastLED.addLeds<NEOPIXEL, DATA_PIN_PHOTO_2>(photo2, 1);
  FastLED.addLeds<NEOPIXEL, DATA_PIN_PHOTO_3>(photo3, 1);
  FastLED.addLeds<NEOPIXEL, DATA_PIN_PHOTO_4>(photo4, 1);
  
  photo1[0] = CHSV(255, 0, 0);
  photo2[0] = CHSV(255, 0, 0);
  photo3[0] = CHSV(255, 0, 0);
  photo4[0] = CHSV(255, 0, 0);
  
  setup_debug();
  
  Serial.println("Setup OK");
}

void setup_debug() {
  Serial.print("TICK_1");
  Serial.println(TICK_1);
  Serial.print("TICK_2=");
  Serial.println(TICK_2);
  Serial.print("TICK_3=");
  Serial.println(TICK_3);
  Serial.print("TICK_4=");
  Serial.println(TICK_4);
  Serial.print("TICK_TOTAL=");
  Serial.println(TICK_TOTAL);
}

void loop() {
  animation(photo1, currentTick + (TICK_TOTAL * PHOTO_1_START_OFFSET));
  animation(photo2, currentTick + (TICK_TOTAL * PHOTO_2_START_OFFSET));
  animation(photo3, currentTick + (TICK_TOTAL * PHOTO_3_START_OFFSET));
  animation(photo4, currentTick + (TICK_TOTAL * PHOTO_4_START_OFFSET));

  delay(ANIMATION_REFRESH_INTERVAL);

  currentTick += 1;
  currentTick %= TICK_TOTAL;

  FastLED.show();
}

void animation(CRGB *photo, int tick) {
  uint8_t brightness;
  if (tick <= TICK_1) {
    // Light on
    brightness = (tick / TICK_1) * 255;
    photo[0] = CHSV(255, 0, brightness);
  }
  else if (tick <= TICK_2) {
    // Light off
    brightness = 255 - (((tick - TICK_1) / (TICK_2 - TICK_1)) * 255);
    photo[0] = CHSV(255, 0, brightness);  
  }
  else if (tick <= TICK_3) {
    // Light on
    brightness = ((tick - TICK_2) / (TICK_3 - TICK_2)) * 255;
    photo[0] = CHSV(255, 0, brightness);
  }
  else if (tick <= TICK_4) {
    // Light off
    brightness = 255 - (((tick - TICK_3) / (TICK_4 - TICK_3)) * 255);
    photo[0] = CHSV(255, 0, brightness);  
  }
}