from machine import Pin, PWM, ADC
import time

# Inisialisasi Pin
TRIG = Pin(28, Pin.OUT)
ECHO = Pin(27, Pin.IN)
pir = Pin(21, Pin.IN)
pot = ADC(Pin(26))
servo = PWM(Pin(15))
servo.freq(50)
buzzer = PWM(Pin(14))
buzzer.duty_u16(0)

# Fungsi Bantu
def map_value(value, in_min, in_max, out_min, out_max):
    return int((value - in_min) * (out_max - out_min) / (in_max - in_min) + out_min)

def set_servo_angle(angle):
    duty = map_value(angle, 0, 180, 1638, 8192)
    servo.duty_u16(duty)

def baca_jarak():
    TRIG.low()
    time.sleep_us(2)
    TRIG.high()
    time.sleep_us(10)
    TRIG.low()
    while ECHO.value() == 0:
        start = time.ticks_us()
    while ECHO.value() == 1:
        end = time.ticks_us()
    durasi = end - start
    jarak = (durasi * 0.0343) / 2
    return jarak

# Melodi Suhu Rendah
def play_low_temp_melody():
    for freq in [440, 494, 523]:
        buzzer.freq(freq)
        buzzer.duty_u16(32768)
        time.sleep_ms(200)
        buzzer.duty_u16(0)
        time.sleep_ms(50)

# Status awal
palang_tertutup = False
mode_otomatis = False

while True:
    try:
        jarak = baca_jarak()
        print("Jarak:", jarak)

        # Mode otomatis: kereta terdeteksi
        if jarak < 30:
            if not mode_otomatis:
                print("🚆 Kereta terdeteksi - Mode Otomatis aktif")
            set_servo_angle(120)
            palang_tertutup = True
            mode_otomatis = True

        else:
            # Hanya aktifkan potensiometer jika tidak dalam mode otomatis
            if mode_otomatis:
                print("✅ Tidak ada kereta - Mode Manual aktif")
                mode_otomatis = False

            # Mode manual dari potensiometer
            pot_val = pot.read_u16()
            angle = map_value(pot_val, 0, 65535, 0, 180)
            print("🎛️ Potensio angle:", angle)
            set_servo_angle(angle)
            palang_tertutup = angle >= 90

        # Deteksi gerakan saat palang tertutup
        if palang_tertutup and pir.value() == 1:
            print("🚶 PIR mendeteksi saat palang tertutup!")
            play_low_temp_melody()
        else:
            buzzer.duty_u16(0)

        time.sleep(0.2)

    except Exception as e:
        print("⚠️ Error:", e)
        buzzer.duty_u16(0)
        servo.duty_u16(0)
        time.sleep(1)