raspberrypi ultrasonic

rpi ultrasonic

import RPi.GPIO as GPIO
import time

GPIO.setwarnings(False)
GPIO.cleanup()
GPIO.setmode(GPIO.BCM)

TRIG = 4
ECHO = 18
GREEN = 17
YELLOW = 27
RED = 22

GPIO.setup(TRIG,GPIO.OUT)
GPIO.setup(ECHO,GPIO.IN)
GPIO.setup(GREEN,GPIO.OUT)
GPIO.setup(YELLOW,GPIO.OUT)
GPIO.setup(RED,GPIO.OUT)

def green_light():
  GPIO.output(GREEN, GPIO.HIGH)
  GPIO.output(YELLOW, GPIO.LOW)
  GPIO.output(RED, GPIO.LOW)

def yellow_light():
  GPIO.output(GREEN, GPIO.LOW)
  GPIO.output(YELLOW, GPIO.HIGH)
  GPIO.output(RED, GPIO.LOW)

def red_light():
  GPIO.output(GREEN, GPIO.LOW)
  GPIO.output(YELLOW, GPIO.LOW)
  GPIO.output(RED, GPIO.HIGH)

def get_distance():
  GPIO.output(TRIG, True)
  time.sleep(0.00001)
  GPIO.output(TRIG, False)

  while GPIO.input(ECHO) == False:
    start = time.time()

  while GPIO.input(ECHO) == True:
    end = time.time()
    
  signal_time = end-start
  distance = signal_time / 0.000058  
  return distance

while True:
  distance = get_distance()
  time.sleep(0.05)
  print(distance)

  if distance >= 25:
    green_light()

  elif 25 > distance > 10:
    yellow_light()

  elif distance <= 5:
    red_light()