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

sleep(0.1)
led=(PWM(Pin(7),freq=500),PWM(Pin(6),freq=500),
     PWM(Pin(5),freq=500))
pot=(ADC(Pin(28)),ADC(Pin(27)),ADC(Pin(26)))

while 1:
    for i,j in zip(led,pot):
        i.duty_u16(j.read_u16())
    sleep(0.5)
    for i in led:
        i.duty_u16(0)
    sleep(0.5)