from machine import Pin,PWM
import machine
import time

led=PWM(Pin(23),5000)
trigger=Pin(13,Pin.OUT)
echo=Pin(12,Pin.IN)

intensity=0
while True:
    trigger.value(0)
    time.sleep_us(1)
    trigger.value(1)
    time.sleep_us(10)
    trigger.value(0)
    totaltime=machine.time_pulse_us(echo,1)
    distance=(totaltime*0.034)/2
    intensity=int(distance)
    led.duty(intensity)
    time.sleep(1)