from machine import Pin, ADC, I2C
import time

# =========================
# Pines
# =========================
PIN_DIR    = 2
PIN_STEP   = 3
PIN_ENABLE = 4
PIN_BOMBA  = 15

LED_SECO    = 6
LED_MEDIO   = 7
LED_MOJADO  = 8

ADC_PIN = 26

# =========================
# LCD I2C
# =========================
I2C_SDA = 0
I2C_SCL = 1
LCD_ADDR = 0x27

# =========================
# Hardware
# =========================
dir_pin    = Pin(PIN_DIR, Pin.OUT)
step_pin   = Pin(PIN_STEP, Pin.OUT)
enable_pin = Pin(PIN_ENABLE, Pin.OUT)
bomba_pin  = Pin(PIN_BOMBA, Pin.OUT)

led_seco  = Pin(LED_SECO, Pin.OUT)
led_medio = Pin(LED_MEDIO, Pin.OUT)
led_mojado= Pin(LED_MOJADO, Pin.OUT)

adc = ADC(ADC_PIN)

# =========================
# Umbrales
# =========================
UMBRAL_BAJO = 30
UMBRAL_ALTO = 60

STEP_DELAY_US = 1600
STEP_BURST_MS = 400

# =============================
#   FILTRO DE HUMEDAD (20 muestras)
# =============================
BUFFER = [0] * 20
index = 0

def leer_humedad_filtrada():
    global index

    raw = adc.read_u16()
    BUFFER[index] = raw
    index = (index + 1) % 20

    promedio = sum(BUFFER) / len(BUFFER)
    pct = (promedio / 65535) * 100

    # limitar
    return max(0, min(100, pct))

# =============================
#   LCD DRIVER 100% SEGURO
# =============================
i2c = I2C(0, sda=Pin(I2C_SDA), scl=Pin(I2C_SCL), freq=400000)

def lcd_send(nibble, rs):
    data = nibble | (0x01 if rs else 0x00)
    i2c.writeto(LCD_ADDR, bytes([data | 0x04]))   # EN = 1
    i2c.writeto(LCD_ADDR, bytes([data]))          # EN = 0

def lcd_cmd(cmd):
    lcd_send(cmd & 0xF0, 0)
    lcd_send((cmd << 4) & 0xF0, 0)

def lcd_char(ch):
    hi = ch & 0xF0
    lo = (ch << 4) & 0xF0
    lcd_send(hi, 1)
    lcd_send(lo, 1)

def lcd_print(text, line=1):
    text = str(text)

    # rellenar manual, sin usar .ljust()
    if len(text) < 16:
        text = text + (" " * (16 - len(text)))
    else:
        text = text[:16]

    lcd_cmd(0x80 if line == 1 else 0xC0)
    for c in text:
        lcd_char(ord(c))

def lcd_init():
    time.sleep_ms(50)
    lcd_cmd(0x33)
    lcd_cmd(0x32)
    lcd_cmd(0x28)
    lcd_cmd(0x0C)
    lcd_cmd(0x06)
    lcd_cmd(0x01)
    time.sleep_ms(5)

# =============================
#   Control motor
# =============================
def motor_on():
    enable_pin.value(0)   # habilita A4988
    bomba_pin.value(1)    # informa al chip

def motor_off():
    enable_pin.value(1)   # deshabilita A4988
    bomba_pin.value(0)

def mover_motor(ms, delay_us):
    end_t = time.ticks_add(time.ticks_ms(), ms)
    while time.ticks_diff(end_t, time.ticks_ms()) > 0:
        step_pin.value(1)
        time.sleep_us(delay_us//2)
        step_pin.value(0)
        time.sleep_us(delay_us//2)

# =============================
#         MAIN LOOP
# =============================
lcd_init()
bomba_activa = False

while True:
    humedad = leer_humedad_filtrada()

    # LEDs
    led_seco.value(1 if humedad < UMBRAL_BAJO else 0)
    led_medio.value(1 if UMBRAL_BAJO <= humedad <= UMBRAL_ALTO else 0)
    led_mojado.value(1 if humedad > UMBRAL_ALTO else 0)

    # Histeresis
    if humedad < UMBRAL_BAJO and not bomba_activa:
        bomba_activa = True
        motor_on()

    elif humedad > UMBRAL_ALTO and bomba_activa:
        bomba_activa = False
        motor_off()

    # Estado del suelo
    if humedad < UMBRAL_BAJO:
        estado_suelo = "SECO"
    elif humedad <= UMBRAL_ALTO:
        estado_suelo = "PERFECTO"
    else:
        estado_suelo = "MOJADO"

    estado_motor = "ENCENDIDO" if bomba_activa else "APAGADO"

    # LCD
    lcd_print("Humedad: " + str(int(humedad)) + "%", 1)
    lcd_print(estado_suelo + "  " + estado_motor, 2)

    if bomba_activa:
        mover_motor(STEP_BURST_MS, STEP_DELAY_US)
    else:
        time.sleep(0.3)