from machine import Pin, ADC
from time import sleep, sleep_us, ticks_us, ticks_diff

# =====================================================
# LCD 16x2 SIN I2C - MODO 4 BITS
# =====================================================

LCD_RS = Pin(16, Pin.OUT)
LCD_E  = Pin(17, Pin.OUT)
LCD_D4 = Pin(18, Pin.OUT)
LCD_D5 = Pin(19, Pin.OUT)
LCD_D6 = Pin(20, Pin.OUT)
LCD_D7 = Pin(21, Pin.OUT)

# =====================================================
# SENSOR ULTRASONICO HC-SR04
# =====================================================

TRIG = Pin(14, Pin.OUT)
ECHO = Pin(15, Pin.IN)

# =====================================================
# POTENCIOMETRO
# =====================================================

pot = ADC(26)   # GP26 / ADC0

# =====================================================
# LEDS
# =====================================================

led1 = Pin(2, Pin.OUT)
led2 = Pin(3, Pin.OUT)
led3 = Pin(4, Pin.OUT)
led4 = Pin(5, Pin.OUT)
led5 = Pin(6, Pin.OUT)
led6 = Pin(7, Pin.OUT)
led7 = Pin(8, Pin.OUT)
led8 = Pin(9, Pin.OUT)

leds = [led1, led2, led3, led4, led5, led6, led7, led8]

# =====================================================
# FUNCIONES LCD
# =====================================================

def lcd_pulso_enable():
    LCD_E.value(1)
    sleep_us(2)
    LCD_E.value(0)
    sleep_us(50)

def lcd_enviar_nibble(data):
    LCD_D4.value((data >> 0) & 1)
    LCD_D5.value((data >> 1) & 1)
    LCD_D6.value((data >> 2) & 1)
    LCD_D7.value((data >> 3) & 1)
    lcd_pulso_enable()

def lcd_enviar_byte(data, rs):
    LCD_RS.value(rs)
    lcd_enviar_nibble(data >> 4)
    lcd_enviar_nibble(data & 0x0F)

def lcd_comando(cmd):
    lcd_enviar_byte(cmd, 0)
    sleep_us(100)

def lcd_caracter(char):
    lcd_enviar_byte(ord(char), 1)

def lcd_limpiar():
    lcd_comando(0x01)
    sleep(0.002)

def lcd_gotoxy(col, fila):
    if fila == 0:
        direccion = 0x80 + col
    else:
        direccion = 0xC0 + col
    lcd_comando(direccion)

def lcd_print(texto):
    for c in texto:
        lcd_caracter(c)

def lcd_init():
    sleep(0.05)

    LCD_RS.value(0)
    LCD_E.value(0)

    lcd_enviar_nibble(0x03)
    sleep(0.005)

    lcd_enviar_nibble(0x03)
    sleep_us(150)

    lcd_enviar_nibble(0x03)
    sleep_us(150)

    lcd_enviar_nibble(0x02)

    lcd_comando(0x28)  # 4 bits, 2 lineas
    lcd_comando(0x0C)  # display ON, cursor OFF
    lcd_comando(0x06)  # incremento automatico
    lcd_limpiar()

# =====================================================
# FUNCIONES DEL SISTEMA
# =====================================================

def apagar_leds():
    for led in leds:
        led.value(0)

def medir_distancia():
    TRIG.value(0)
    sleep_us(2)

    TRIG.value(1)
    sleep_us(10)
    TRIG.value(0)

    timeout = 30000

    inicio_espera = ticks_us()
    while ECHO.value() == 0:
        if ticks_diff(ticks_us(), inicio_espera) > timeout:
            return 999.0

    inicio_pulso = ticks_us()

    while ECHO.value() == 1:
        if ticks_diff(ticks_us(), inicio_pulso) > timeout:
            return 999.0

    fin_pulso = ticks_us()

    duracion = ticks_diff(fin_pulso, inicio_pulso)

    distancia = (duracion * 0.0343) / 2

    return distancia

def leer_potenciometro():
    valor = pot.read_u16()
    porcentaje = int((valor * 100) / 65535)
    return porcentaje

def controlar_leds(distancia):
    apagar_leds()

    if distancia > 19.8:
        led5.value(1)

    elif distancia > 16.4:
        led6.value(1)
        led7.value(1)

    elif distancia > 9.6:
        led1.value(1)
        led7.value(1)
        led8.value(1)

    elif distancia > 8.0:
        led1.value(1)
        led3.value(1)
        led4.value(1)

    else:
        led2.value(1)

def texto_leds(distancia):
    if distancia > 19.8:
        return "LED:5"

    elif distancia > 16.4:
        return "LED:6 7"

    elif distancia > 9.6:
        return "LED:1 7 8"

    elif distancia > 8.0:
        return "LED:1 3 4"

    else:
        return "LED:2"

def mostrar_lcd(distancia, pot_porcentaje):
    lcd_limpiar()

    lcd_gotoxy(0, 0)
    lcd_print("D:{:.1f}cm P:{}%".format(distancia, pot_porcentaje))

    lcd_gotoxy(0, 1)
    lcd_print(texto_leds(distancia))

# =====================================================
# PROGRAMA PRINCIPAL
# =====================================================

lcd_init()

lcd_gotoxy(0, 0)
lcd_print("Sistema HC-SR04")
lcd_gotoxy(0, 1)
lcd_print("Raspberry Pico")
sleep(2)

while True:
    distancia = medir_distancia()
    pot_porcentaje = leer_potenciometro()

    controlar_leds(distancia)
    mostrar_lcd(distancia, pot_porcentaje)

    sleep(0.3)