from machine import Pin, ADC, Timer
from time import sleep
import time
from math import log

analog = ADC(Pin(26))
button = Pin(15, Pin.IN, Pin.PULL_DOWN)
led = Pin(2, Pin.OUT)


button_toggled = False
def interrupt_callback(pin):
    global button_toggled
    stamp = 2
    pressed_time = time.ticks_ms() - stamp
    if pressed_time >= 199.99:
        button_toggled = True
        stamp = pressed_time

def toggle(pin):
    led.toggle()
button.irq(trigger=Pin.IRQ_RISING, handler=interrupt_callback)
timer = Timer(period=1000, mode=Timer.PERIODIC, callback=toggle)

while True:
    if button_toggled == True:
        BETA = 3950
        value = analog.read_u16()
        celsius = round(1 / (log(1 / (65535. / value - 1)) / BETA + 1.0 / 298.15) - 273.15)
        print(f"{celsius}°C")
        button_toggled = False
    if button_toggled == False:
        sleep(0.5)