import time
from machine import Pin, ADC, I2C, SoftI2C,
from pico_i2c_lcd import I2cLcd
import math

i2c = SoftI2C(sda=Pin(20),scl=Pin(19),freq=400000)
led = Pin(5, Pin.OUT)
lcd_addr = i2c.scan()[0]

lcd = I2cLcd(i2c,lcd_addr, 2, 16)
lcd.clear()
lcd.move_to(5,1)

beta = 3950


adc = ADC(28)
while True:
    led.off()
    lcd.clear()
    lcd.move_to(5,1)
    tmp = adc.read_u16()
    celsius = 1 / (math.log(1 / (65536 / tmp - 1)) / beta + 1.0 / 298.15) - 273.15;
    celsius = round(celsius,2)
    print(celsius)
    if celsius > 40:
        led.on()
    lcd.putstr("{0} C".format(celsius))
    
    time.sleep(1)