import RPi.GPIO as GPIO
import random

PIN = 17

GPIO.setmode(GPIO.BCM)
GPIO.setup(PIN, GPIO.IN)

def leggi_aria():

    valore = GPIO.input(PIN)

    if valore == 0:
        ppm = round(random.uniform(0.12, 0.20), 2)
        stato = "ARIA CRITICA"
    else:
        ppm = round(random.uniform(0.03, 0.09), 2)
        stato = "ARIA OTTIMALE"

    return ppm, stato