from machine import Pin
import time
relay=Pin(12,Pin.OUT)
relay2=Pin(17,Pin.OUT)
relay.on()
trig=Pin(32,Pin.OUT)
echo=Pin(33,Pin.IN)
t=Ton=Toff=distance=0
while 1:
    trig.on()
    time.sleep_us(10)
    trig.off()
    time.sleep_us(2)
    while echo.value==0:
        Toff=time.ticks_us()
    while echo.value==1:
        Ton=time.ticks_us()    
    t=(Ton-Toff)
    distance= (t*0.034   ) /2
    print(distance)
    time.sleep_ms(50)