from machine import Pin, ADC
import utime

sensor = ADC(Pin(35))
sensor.atten(ADC.ATTN_11DB) 
sensor.width(ADC.WIDTH_12BIT)
led = Pin(18, Pin.OUT)

while True:
    medicion = float(sensor.read())
    conversion = round(medicion * 100 / 4096, 2)
    print(conversion)
    utime.sleep(1) 
    if conversion > 20:
        led.value(1)
    else:{
        led.value(0)
    }