print("script starting")

from time import sleep, sleep_ms
from machine import Pin, SPI, PWM
from mfrc522 import MFRC522

sck = Pin(18)
mosi = Pin(23)
miso = Pin(19)

spi = SPI(
    baudrate=100000,
    polarity=0,
    phase=0,
    sck=sck,
    mosi=mosi,
    miso=miso
)

CS_PIN = 5
rdr = MFRC522(spi, CS_PIN)
print("reader initialized")

servo = PWM(Pin(32), freq=50)

def servo_angle(angle):
    duty = int(40 + (angle / 180) * (115 - 40))
    servo.duty(duty)

def gate_open():
    servo_angle(90)

def gate_close():
    servo_angle(0)

gate_close()

def uid_to_string(uid_bytes):
    return "".join("{:02X}".format(b) for b in uid_bytes)

print("scan an RFID tag...")

while True:
    stat, tag_type = rdr.request(rdr.REQIDL)
    if stat == rdr.OK:
        stat, raw_uid = rdr.anticoll()
        if stat == rdr.OK:
            uid_str = uid_to_string(raw_uid[:4])
            print("card detected, UID:", uid_str)
            print("opening gate")
            gate_open()
            sleep(3)
            print("closing gate")
            gate_close()
            sleep_ms(1000)
        elif stat != rdr.OK:
            print("no card detected UID:", uid_str)
   sleep_ms(50)