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

pinLED = 4
pinPot = 28

myLED = PWM(Pin(pinLED))
myPot = ADC(pinPot)
myLED.freq(1000)
myLED.duty_u16(0)

while True:
    potValue = myPot.read_u16()
    myLED.duty_u16(int(potValue))
    sleep (0.1)