#include <FastLED.h>

#define LED_PIN     6    // Pin connected to the LED data input
#define NUM_LEDS    40   // Total number of LEDs in the strip
#define LED_TYPE    WS2812B
#define COLOR_ORDER GRB  // Color order of the LED strip (typically GRB for WS2812B)

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);
  FastLED.setBrightness(100);  // Set initial brightness (0-255)
}

void loop() {
  static uint8_t startIndex = 0;  // Start index for the chaser effect

  // Update all LEDs
  for (int i = 0; i < NUM_LEDS; i++) {
    // Determine brightness based on distance from the current position
    int distance = abs(startIndex - i);
    int brightness = 255 - map(distance, 0, NUM_LEDS / 2, 0, 255); // Map distance to brightness range

    // Set color with fading tail
    leds[i] = CRGB(brightness, brightness, brightness);
  }

  FastLED.show();  // Update the LED strip with the new colors

  // Move the chaser effect forward smoothly
  startIndex = (startIndex + 1) % NUM_LEDS;

  // Delay to control the speed of the chaser effect (approximately 1.5 seconds per cycle)
  delay(100 / NUM_LEDS);
}