Laser

#!/usr/local/bin/python

import RPi.GPIO as GPIO
import time
radi=False

GPIO.setmode(GPIO.BOARD)
GPIO.setup(12,GPIO.OUT)
GPIO.output(12,GPIO.LOW)
pin_to_circuit = 7
password=""
i=0
def rc_time (pin_to_circuit) :
    count = 0

    GPIO.setup(pin_to_circuit, GPIO.OUT)
    GPIO.output(pin_to_circuit, GPIO.LOW)
    time.sleep(0.02)

    GPIO.setup(pin_to_circuit, GPIO.IN)

    while (GPIO.input(pin_to_circuit) == GPIO.LOW) :
        count += 1

    return count


try:
    while True:

        if rc_time(pin_to_circuit)>100:
            radi=True
            while(radi):
                while(i<5):
                    GPIO.output(12,GPIO.HIGH)
                    time.sleep(0.25)
                    GPIO.output(12,GPIO.LOW)
                    time.sleep(0.5)
                    i=i+1
                if(i==5):
                    GPIO.output(12,GPIO.HIGH)
                    i=0
                print"Unesite sifru: "
                password=str(raw_input())
                if(password=="pilab01"or password=="pilab02"):
                    radi=False
                    GPIO.output(12,GPIO.LOW)
                else:
                    print "Pogresna lozinka!Ponovo unesite"
                    i=0

        if(password=="pilab02"):
            print"sistem je ugasen"
            break
        time.sleep(10)
except KeyboardInterrupt:
    pass
finally:
    GPIO.cleanup()