from machine import Pin, PWM, ADC
from time import sleep

led = PWM(Pin(4), 5000)
ldr = ADC(Pin(34))
ldr.width(ADC.WIDTH_10BIT)
ldr.atten(ADC.ATTN_11DB)

while True:
    x = ldr.read()
    print(x)
    
    brightness = 1023 - x 
    
    led.duty(brightness) 

    sleep(0.1)