import RPi.GPIO as GPIO  
import time  
GPIO.setmode(GPIO.BCM)  
GPIO_TRIG = 11 
 GPIO_ECHO = 18 
GPIO.setup(GPIO_TRIG, GPIO.OUT) 
GPIO.setup(GPIO_ECHO, GPIO.IN)
GPIO.output(GPIO_TRIG, GPIO.LOW) 
 Time.sleep(2)  
GPIO.output(GPIO_TRIG, GPIO.HIGH) 
 Time.sleep(0.00001)  
GPIO.output(GPIO_TRIG, GPIO.LOW) 
 while GPIO.input(GPIO_ECHO)==0:  
  start_time = time.time()  
while GPIO.input(GPIO_ECHO)==1: 
 Bounce_back_time = time.time()  
 pulse_duration = Bounce_back_time - start_time 
 distance = round(pulse_duration * 17150, 2)  
print (f"Distance: {distance} cm")  
GPIO.cleanup()