from machine import Pin, I2C
from onewire import OneWire
from ds18x20 import DS18X20
from time import sleep_ms
from lcd_api import LcdApi
from pico_i2c_lcd import I2cLcd
import _thread

# Relais
relais  = Pin(18, machine.Pin.OUT, value = 1)
led_onboard = Pin(25, machine.Pin.OUT, value = 0)

# Temperature
temp_sensor = DS18X20(OneWire(Pin(28)))
sensor_id   = temp_sensor.scan()[0]

# LCD Display
i2c = I2C(1, sda=Pin(26), scl=Pin(27), freq=400000)
I2C_ADDR     = 0x27
I2C_NUM_ROWS = 2
I2C_NUM_COLS = 16
lcd = I2cLcd(i2c, I2C_ADDR, I2C_NUM_ROWS, I2C_NUM_COLS)

# Custom characters
degree = (
    0b00111,
    0b00101,
    0b00111,
    0b00000,
    0b00000,
    0b00000,
    0b00000,
    0b00000,
    )

# Buttons
button1 = Pin(17, Pin.IN, Pin.PULL_DOWN)
button2 = Pin(16, Pin.IN, Pin.PULL_DOWN)
button3 = Pin(15, Pin.IN, Pin.PULL_DOWN)
global button1_pressed
global button2_pressed
global button3_pressed
button1_pressed = False
button2_pressed = False
button3_pressed = False

def ctrl_relais(active = True):
    if active:
        relais.value(0)
        led_onboard.on()
    else:
        relais.value(1)
        led_onboard.off()
        
def button_reader_thread():
    global button1_pressed
    global button2_pressed
    global button3_pressed
    while True:
        if button1.value() == 1:
            button1_pressed = True
        if button2.value() == 1:
            button2_pressed = True
        if button3.value() == 1:
            button3_pressed = True
        sleep_ms(100)

lcd.backlight_on()
lcd.clear()
lcd.custom_char(0, degree)

temp_tgt = 28.0
temp_gap = 0.5
is_heating  = False
heat_string = ""
system_on = False
system_on_string = ""

_thread.start_new_thread(button_reader_thread, ())

while True:
    temp_sensor.convert_temp()
    sleep_ms(750)
    temp_curr = temp_sensor.read_temp(sensor_id)
        
    if button1_pressed == True:
        temp_tgt -= 0.5
        button1_pressed = False
    if button2_pressed == True:
        temp_tgt += 0.5
        button2_pressed = False
    if button3_pressed == True:
        system_on = not system_on
        button3_pressed = False

    if system_on == True and temp_curr < temp_tgt - temp_gap:
        is_heating = True
    elif system_on == True and temp_curr > temp_tgt + temp_gap:
        is_heating = False

    ctrl_relais(is_heating)
        
    if system_on == True:
        system_on_string = "ON "
    else:
        system_on_string = "OFF"
        is_heating = False

    if is_heating == True:
        heat_string = ">H<"
    else:
        heat_string = "   "

    lcd.move_to(0, 0)
    lcd.putstr("ACT: {0:3.1f}".format(temp_curr) + chr(0) + "C  " + heat_string +
               "\nTGT: {0:3.1f}".format(temp_tgt) + chr(0) + "C  " + system_on_string)