from machine import Pin, ADC, PWM
import time

ldr = ADC(Pin(28))
led_pwm = PWM(Pin(13))
led_pwm.freq(1000)

while True:

    luz = ldr.read_u16()
    
    brillo = 65535 - luz
    
    led_pwm.duty_u16(brillo)
    
    time.sleep(0.05)