from machine import Pin, PWM
import time

# LED
led = Pin(2, Pin.OUT)

# Buzzer
buzzer = PWM(Pin(15))
buzzer.freq(1000)

# Servo
servo = PWM(Pin(18))
servo.freq(50)

# Password
PASSWORD = "1234"
entered = ""

# Keypad
rows = [Pin(13, Pin.OUT),
        Pin(12, Pin.OUT),
        Pin(14, Pin.OUT),
        Pin(27, Pin.OUT)]

cols = [Pin(26, Pin.IN, Pin.PULL_DOWN),
        Pin(25, Pin.IN, Pin.PULL_DOWN),
        Pin(33, Pin.IN, Pin.PULL_DOWN),
        Pin(32, Pin.IN, Pin.PULL_DOWN)]

keys = [
    ['1','2','3','A'],
    ['4','5','6','B'],
    ['7','8','9','C'],
    ['*','0','#','D']
]

def set_angle(angle):
    duty = int((angle / 180) * 75 + 40)
    servo.duty(duty)

def lock():
    set_angle(0)

def unlock():
    set_angle(90)

def beep():
    buzzer.duty(512)
    time.sleep(0.2)
    buzzer.duty(0)

def alarm():
    for _ in range(5):
        buzzer.duty(512)
        led.on()
        time.sleep(0.2)
        buzzer.duty(0)
        led.off()
        time.sleep(0.2)

def read_key():
    for r in range(4):
        for row in rows:
            row.value(0)

        rows[r].value(1)

        for c in range(4):
            if cols[c].value():
                while cols[c].value():
                    pass
                return keys[r][c]

    return None

lock()

print("Enter PIN")

while True:
    key = read_key()

    if key:
        print("Pressed:", key)
        beep()

        if key.isdigit():
            entered += key
            print("*" * len(entered))

        if len(entered) == 4:

            if entered == PASSWORD:
                print("ACCESS GRANTED")
                led.on()

                unlock()
                time.sleep(5)

                lock()
                led.off()

            else:
                print("WRONG PASSWORD")
                alarm()

            entered = ""

        time.sleep(0.2)