Universal lightsaber blade, with illumination

With this model, you can equip any lightsaber hilt with a blade of approx. 1m. You have the choice of whether to even install a 2m NeoPixel RGB strip in the sword.

For illumination, you need an Arduino Nano, a WS2812B 2m RGB strip, cables, and a 5V battery pack. I use two 18650 batteries as the battery.

This is the code for the Arduino Nano:

#include <FastLED.h>

#define NUM_LEDS 120

#define DATA_PIN 4

CRGB leds[NUM_LEDS];

#define BLADE_GREEN CRGB(0,255,0)

#define TIP_WHITE  CRGB(255,255,255)

#define TIP_SIZE 5      // Number of LEDs at the tip

#define DELAY_UP 20     // Speed of powering up

#define SHIMMER 50      // Brightness for shimmer

void setup() {

  FastLED.addLeds<WS2812B, DATA_PIN, GRB>(leds, NUM_LEDS);

  FastLED.clear();

  FastLED.show();

  // Power-on animation from bottom to top

  for(int i=0; i<NUM_LEDS/2; i++) {

    // Base green

    leds[i] = BLADE_GREEN;

    leds[NUM_LEDS-1-i] = BLADE_GREEN;

    // Optional: slight shimmer on adjacent LEDs

    if(i>0) {

      leds[i-1].fadeToBlackBy(SHIMMER);          

      leds[NUM_LEDS-i].fadeToBlackBy(SHIMMER);

    }

    FastLED.show();

    delay(DELAY_UP);

  }

  // Tip white

  for(int i=0; i<TIP_SIZE; i++){

    leds[i] = TIP_WHITE;

    leds[NUM_LEDS-1-i] = TIP_WHITE;

  }

  FastLED.show();

}

void loop() {

  // Blade permanently green with white tip

  for(int i=TIP_SIZE; i<NUM_LEDS/2; i++){

    leds[i] = BLADE_GREEN;

    leds[NUM_LEDS-1-i] = BLADE_GREEN;

  }

  // Optional: subtle “Glow” effect

  for(int i=TIP_SIZE; i<NUM_LEDS/2; i++){

    byte flicker = random8(10); // small flicker for Glow

    leds[i].nscale8(250 + flicker);

    leds[NUM_LEDS-1-i].nscale8(250 + flicker);

  }

  FastLED.show();

  delay(30);

}

All these values can be adjusted to change the color or the number of LEDs. 

A suitable battery holder for this lightsaber: https://makerworld.com/en/models/602073-obi-wan-lightsaber-with-iluminated-crystal-chamber#profileId-524475 can be found here: https://makerworld.com/en/models/1944563-battery-holder-for-lightsaber#profileId-2088800