from machine import Pin,ADC
from utime import sleep

min_time=0.5
max_time=2.5
sleep(0.1)
pot=ADC(Pin(28))
led=(Pin(3,Pin.OUT),Pin(4,Pin.OUT),Pin(5,Pin.OUT),
     Pin(6,Pin.OUT),Pin(7,Pin.OUT),Pin(8,Pin.OUT),
     Pin(9,Pin.OUT),Pin(10,Pin.OUT))

while 1:
    val=pot.read_u16()
    delay=val/65535*(max_time-min_time)+min_time
    print(delay)
    for i in led:
        i.value(not(i.value()))
    sleep(delay)