from machine import Pin
import utime
trig = Pin (28, Pin. OUT)
echo = Pin (27, Pin. IN)

def read ():
    trig.low()
    utime.sleep_us (2)

    trig.high()
    utime.sleep_us(5)
    trig.low()

    while echo.value()==0:
       timeOff = utime.ticks_us()
    while echo.value()==1:
        timeOn = utime.ticks_us()
    
    time = timeOn - timeOff
    distance = (time * 0.043)/2
    return distance
while True:
    print ("distancia es:", read(), "cm")
    utime.sleep (1)