Home smart alarm

import time
import RPi.GPIO as GPIO
import pigpio
import smtplib
import ssl


 
port=465
smtp_server = "smtp.gmail.com"
sender_email= ""
receiver_email= ""
password= ""
message = """\
        Subject: ALARM!!!

        Motion Detected in your house."""



context=ssl.create_default_context()


pi=pigpio.pi()
GPIO.setmode(GPIO.BOARD)
trig=16
echo=18
buzzer=18
button=25
GPIO.setup(trig,GPIO.OUT)
GPIO.setup(echo,GPIO.IN)
pi.set_mode(buzzer,pigpio.OUTPUT)
pi.set_pull_up_down(button,pigpio.PUD_UP)

def calculateDist():
        GPIO.output(trig,GPIO.LOW)
        time.sleep(0.05)
        GPIO.output(trig,GPIO.HIGH)
        time.sleep(0.00001)
        GPIO.output(trig,GPIO.LOW)

        start=time.time()
        stop=time.time()

        while GPIO.input(echo)==0:
            start=time.time()

        while GPIO.input(echo)==1:
            stop=time.time()

        duration=stop-start

        distance=34300/2*duration

        #if distance < 3400:
            #print("Distance = %.2f" % distance)
        return distance 
      

print("The system calibrating...")
i=0
val=0
while i<20:
    val=val+calculateDist()
    i=i+1
    #print(i)
val=val/20
print("Average value: %.2f" % val)

try:
    while True:
        ti=0
        ok=True
        dist=calculateDist()
        eroare=val-dist
        if(eroare<0):
            eroare=eroare*(-1)
        while ok:
            #print("Everything is fine!")
            dist=calculateDist()
            eroare=val-dist
            if(eroare<0):
                eroare=eroare*(-1)
            if(eroare<5*val/100):
                ok=True
            else:
                if(ti==0):
                    ok=True
                    ti=ti+1
                else:
                    ok=False
        pi.hardware_PWM(buzzer,500,500000)
        with smtplib.SMTP_SSL(smtp_server,port,context=context) as server:
            server.login(sender_email,password)
            server.sendmail(sender_email,receiver_email, message)
        i=0
        while pi.read(button)==1:
            if pi.read(buzzer)==0:
                start=time.time()
                while pi.read(buzzer)==0:
                    stop=time.time()
                    print(stop-start)
                    i=i+1
                    if(stop-start>1):
                        break
                if(stop-start>1):
                    break
            #print("ALARMA %d" % ti)
        pi.hardware_PWM(buzzer,0,0)
except KeyboardInterrupt:
    pass

pi.write(buzzer,0)
pi.stop()
GPIO.cleanup()