from machine import Pin, I2C, ADC, Timer
from pico_i2c_lcd import I2cLcd
from math import log

sda = Pin(0)
scl = Pin(1)

i2c = I2C(0, sda=sda, scl=scl, freq=40000)

devices = i2c.scan()

if len(devices) <= 0:
  print("No devices found!")
else:
  print(hex(devices[0]))

i2c_addr = devices[0]

lcd = I2cLcd(i2c, i2c_addr, 2, 16)

green = Pin(2, Pin.OUT)
yellow = Pin(3, Pin.OUT)
red = Pin(16, Pin.OUT)

adc = ADC(0)
BETA = 3950

cnt = 0
def fn(timer):
    lcd.clear()
    raw_value = adc.read_u16()
    temp_celcius = (1/ (log(1/(65535/raw_value -1))/BETA + (1/298.15))) - 273.15
    global cnt
    if temp_celcius >= 10 and temp_celcius <= 33:
        red.low()
        lcd.putstr(str(temp_celcius))
        green.toggle()
        cnt = 0
    else:
        if cnt <= 5:
            green.low()
            yellow.toggle()
            cnt += cnt + 1
        else:
            yellow.low()
            red.toggle()
            lcd.putstr("DANGER")

timer = Timer(freq=1, mode=Timer.PERIODIC, callback=fn)