#include <FastLED.h>
#define LED_PIN 5       // Replace with the pin number you used for DATA connection
#define NUM_LEDS 20      // Replace with the number of LEDs in your strip
#define FADE_DELAY 1   // Delay between brightness changes (in milliseconds)
#define MAX_BRIGHTNESS 255 // Maximum brightness value
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Increase brightness
  for (int brightness = 0; brightness <= MAX_BRIGHTNESS; brightness++) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
  // Decrease brightness
  for (int brightness = MAX_BRIGHTNESS; brightness >= 0; brightness--) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
}
void setBrightness(int brightness) {
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB(brightness, brightness, brightness);
  }
  FastLED.show();  // Update the LED strip
}