import time
from machine import Pin, I2C, PWM
from hx711 import HX711
from pico_i2c_lcd import PicoI2cLcd

# Konfigurasi Pin Raspberry Pi Pico W
DT_PIN = 14
SCK_PIN = 15
BUZZER_PIN = 16
I2C_SDA = 0
I2C_SCL = 1

# Ambang Batas Overload (4.999 Gram)
THRESHOLD_GRAM = 4999.0

# Inisialisasi Buzzer (PWM)
buzzer = PWM(Pin(BUZZER_PIN))
buzzer.duty_u16(0)  # Buzzer mati secara default

def buzzer_on(freq=2500):
    buzzer.freq(freq)
    buzzer.duty_u16(32768)  # Duty cycle 50%

def buzzer_off():
    buzzer.duty_u16(0)

# Inisialisasi LCD I2C (16x2)
i2c = I2C(0, sda=Pin(I2C_SDA), scl=Pin(I2C_SCL), freq=400000)
devices = i2c.scan()
I2C_ADDR = devices[0] if devices else 0x27
lcd = PicoI2cLcd(i2c, I2C_ADDR, 2, 16)

# -------------------------------------------------------------
# 1. LOADING AWAL BOOT
# -------------------------------------------------------------
lcd.clear()
lcd.move_to(0, 0)
lcd.putstr("  Sistem kerja  ")
lcd.move_to(0, 1)
lcd.putstr(" Overload Lift  ")
time.sleep(3)  # Menampilkan loading awal selama 3 detik

# -------------------------------------------------------------
# 2. INISIALISASI & KALIBRASI SENSOR (TARE)
# -------------------------------------------------------------
lcd.clear()
lcd.move_to(0, 0)
lcd.putstr(" Kalibrasi Lift ")
lcd.move_to(0, 1)
lcd.putstr("Mereset Nol...  ")

hx = HX711(d_out=DT_PIN, sck=SCK_PIN)
CALIBRATION_FACTOR = 420.0  # Skala standar Wokwi untuk load cell 5kg

hx.tare()
hx.set_scale(CALIBRATION_FACTOR)

lcd.clear()

# -------------------------------------------------------------
# 3. LOOP UTAMA PEMBACAAN BEBAN
# -------------------------------------------------------------
while True:
    try:
        # Membaca berat dari sensor dan konversi ke gram
        weight_kg = hx.get_units(times=3)
        weight_gram = weight_kg * 1000.0

        # Menghindari tampilan nilai minus akibat fluktuasi kecil
        if weight_gram < 0:
            weight_gram = 0.0

        # Pengecekan Kondisi Overload (>= 4999 gram)
        if weight_gram >= THRESHOLD_GRAM:
            buzzer_on(2500)  # Buzzer berbunyi
            
            # Tampilan LCD saat Overload & Lift Stop
            lcd.move_to(0, 0)
            lcd.putstr("   OVERLOAD!    ")
            lcd.move_to(0, 1)
            lcd.putstr("Sistem Lift Stop")
            
        else:
            buzzer_off()  # Buzzer tidak berbunyi
            
            # Tampilan LCD kembali ke perhitungan beban normal
            lcd.move_to(0, 0)
            lcd.putstr("Lift: BERJALAN  ")
            lcd.move_to(0, 1)
            lcd.putstr(f"Beban: {weight_gram:.1f}g    ")

        time.sleep(0.2)

    except KeyboardInterrupt:
        buzzer_off()
        print("Program dihentikan.")
        break
    except Exception as e:
        print("Error:", e)
        time.sleep(1)