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
RST_PIN = 17

rst = Pin(RST_PIN, Pin.OUT)
rst.value(0)
sleep_ms(10)
rst.value(1)
sleep_ms(10)

rdr = MFRC522(spi, CS_PIN)

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):
    result = ""
    for b in uid_bytes:
        result = result + "{:02X}".format(b)
    return result

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)
        else:
            print("card present but read failed")
    sleep_ms(50)