Smart Doorbell

#import the necessary modules from the bottle library
from bottle import route, run, template, request
#we will import the RPi.GPIO library with the name of GPIO
import RPi.GPIO as GPIO
import smtplib, ssl
import time
import pigpio
#we will set the pin numbering to the GPIO.BOARD numbering
GPIO.setmode(GPIO.BOARD)

############### DISTANCE SENSOR
#declare the pins used by the ultrasonic module
trig = 16
echo = 18
#set the trigger pin as OUTPUT and the echo as INPUT
GPIO.setup(trig, GPIO.OUT)
GPIO.setup(echo, GPIO.IN)

################ BUZZER
#create an instance of the pigpio library
pi = pigpio.pi()

#define the pin used by the Buzzer
#this is GPIO18, which is pin 12
buzzer = 18

################ LEDS
#define the pin used by the Led
led_closest = 3
led_middle = 5
led_farthest = 7

#set the pin used by the Led as OUTPUT
GPIO.setup(led_closest, GPIO.OUT)
GPIO.setup(led_middle, GPIO.OUT)
GPIO.setup(led_farthest, GPIO.OUT)

smtp_server = "smtp.gmail.com"
port = 587  # For starttls
sender = "gabitim470@gmail.com"
password = 'dummy_passwd' # real passwd is requiered in order to work
receivers = ['gabitim470@gmail.com']
# Create a secure SSL context
context = ssl.create_default_context()

def calculate_distance():
 #set the trigger to HIGH
 GPIO.output(trig, GPIO.HIGH)
 #sleep 0.00001 s and the set the trigger to LOW
 time.sleep(0.00001)
 GPIO.output(trig, GPIO.LOW)
 #save the start and stop times
 start = time.time()
 stop = time.time()
 #modify the start time to be the last time until
 #the echo becomes HIGH
 
 while GPIO.input(echo) == 0:
  start = time.time()
  #modify the stop time to be the last time until
  #the echo becomes LOW
  
 while GPIO.input(echo) == 1:
  stop = time.time()
 
 #get the duration of the echo pin as HIGH
 duration = stop - start
 
 #calculate the distance
 distance = 34300/2 * duration
 
 if distance < 0.5 and distance > 400:
  return 0
 else:
  #return the distance
  if distance < 80:
   notification_message = "You have a visitor!"
   server.sendmail(sender, receivers, notification_message)
   buzzer_function('On')
   update_leds(GPIO.HIGH, GPIO.HIGH, GPIO.HIGH)
  elif distance < 200:
    update_leds(GPIO.LOW, GPIO.HIGH, GPIO.HIGH)
    buzzer_function('Off')
  else: 
    update_leds(GPIO.LOW, GPIO.LOW, GPIO.HIGH)
    buzzer_function('Off')
  
  return distance / 100
  
def buzzer_function(state):
 #if the state is "On", we will turn On the buzzer
 #else, we will turn Off the buzzer
 if state == 'On':
  #turn On the buzzer
  pi.hardware_PWM(buzzer, 1000, 500000)
 else:
  #turn off the buzzer
  pi.hardware_PWM(buzzer, 0, 0)
  
def update_leds(led_closest_state, led_middle_state, led_farthest_state):
 GPIO.output(led_closest, led_closest_state)
 GPIO.output(led_middle, led_middle_state)
 GPIO.output(led_farthest, led_farthest_state)
 
 #define the route for the main page
@route('/')
def index():
 #at the '/' route we will return the index.html
 #template that is in the views folder
 return template('index.html')
 
@route('/refresh')
#define a function to send data to client
def refresh():
 #calculate the distance
 dist = calculate_distance()
 #return the distance to client
 return f'{dist:.2f}' 
  
try:
 server = smtplib.SMTP(smtp_server,port) # starting the smpt server
 server.ehlo() 
 server.starttls(context=context)
 server.ehlo() # Can be omitted
 server.login(sender, password)
 #we will run the app on port 5000
 run(host = '0.0.0.0', port = '5000')
except KeyboardInterrupt:
 pass
#clean the used ports
# server.quit()
GPIO.cleanup()