//Достаточно 50 вместо 100
#include <FastLED.h>
#define LED_PIN     2
#define NUM_LEDS    256

CRGB leds[NUM_LEDS];
void setup() {  FastLED.setBrightness(255);  //итенсив!
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
/*  FastLED.setMaxPowerInVoltsAndMilliamps(5,2500); */  } //!!

void loop() {
  for (int i = 0; i <= NUM_LEDS; i++) {  
    leds[i] = CRGB(0, 0, 255); //Blue
    FastLED.show();        delay(100);
  }
//for (int i = NUM_LEDS; i >= 0; i--) {  
//    leds[i] = CRGB(100, 0, 0); //Red
//    FastLED.show();        delay(1);
//  } 
} 

/*# Питон. Движение Led-тройки. Для Esp32.  Был pin 23 
import neopixel
import time
import machine
import math
pin = 2        # GPIO pin for NeoPixel 
num_leds = 256  
matrix_width  = 16   
matrix_height = 16  

np = neopixel.NeoPixel(machine.Pin(pin), num_leds)  # Initialize NeoPixel

runs=[0,0,0]
for num in range(num_leds):
    print(runs)

    np[runs[0]]=((0,0,0))    
    np[runs[1]]=((0,0,0))
    np[runs[2]]=((0,0,0))
    np.write()

    runs[0]=min(0+num,0+num%num_leds)        
    np[runs[0]]=((0,255,0))
    
    runs[1]=min(1+num,1+num%num_leds)
    np[runs[1]]=((0,255,0))

    runs[2]=min(2+num,2+num%num_leds)     
    np[runs[2]]=((0,255,0))
    np.write()
    time.sleep(0.1)
    
np.fill((0, 0, 0))  # Clear the NeoPixel matrix
np.write()  */