from machine import Pin
import utime
trigger= Pin(3,Pin.OUT)
echo =Pin(2,Pin.IN)
led = machine.Pin(15, machine.Pin.OUT)
buzzer = machine.Pin(14, machine.Pin.OUT)
def ultra():
  trigger.low()
  utime.sleep_us(2)
  trigger.high()
  utime.sleep_us(5)
  trigger.low()

  while echo.value() == 0 :
    signaloff=utime.ticks_us()
  while echo.value() == 1 :
    signalon=utime.ticks_us()
  timepassed=signalon - signaloff
  distance=(timepassed * 0.0343) / 2
  print("The distance from object is",distance,"cm")
  if distance<50:
      for i in range(50):
         led.toggle()
         buzzer.toggle()
         utime.sleep_ms(100)
while True:
  ultra()
  utime.sleep(1)