from machine import Pin, PWM, ADC
import utime
import math

# Sensor Connections
thermistor_pin = machine.Pin(26)
adc = machine.ADC(thermistor_pin)
led = machine.Pin(5, machine.Pin.OUT)
buzz = PWM(Pin(6))
# LCD Connections
rs = machine.Pin(8, machine.Pin.OUT)
e = machine.Pin(9, machine.Pin.OUT)
d4 = machine.Pin(10, machine.Pin.OUT)
d5 = machine.Pin(11, machine.Pin.OUT)
d6 = machine.Pin(12, machine.Pin.OUT)
d7 = machine.Pin(13, machine.Pin.OUT)

def pulseE():
    e.value(1)
    utime.sleep_us(40)
    e.value(0)
    utime.sleep_us(40)

def send2LCD4(BinNum):
    d4.value((BinNum & 0b00000001) >> 0)
    d5.value((BinNum & 0b00000010) >> 1)
    d6.value((BinNum & 0b00000100) >> 2)
    d7.value((BinNum & 0b00001000) >> 3)
    pulseE()

def send2LCD8(BinNum):
    d4.value((BinNum & 0b00010000) >> 4)
    d5.value((BinNum & 0b00100000) >> 5)
    d6.value((BinNum & 0b01000000) >> 6)
    d7.value((BinNum & 0b10000000) >> 7)
    pulseE()
    d4.value((BinNum & 0b00000001) >> 0)
    d5.value((BinNum & 0b00000010) >> 1)
    d6.value((BinNum & 0b00000100) >> 2)
    d7.value((BinNum & 0b00001000) >> 3)
    pulseE()

def setUpLCD():
    rs.value(0)
    send2LCD4(0b0011)
    send2LCD4(0b0011)
    send2LCD4(0b0011)
    send2LCD4(0b0010)
    send2LCD8(0b00101000)
    send2LCD8(0b00001100)
    send2LCD8(0b00000110)
    send2LCD8(0b00000010)
    utime.sleep_ms(2)

def send_string_to_lcd(string):
    rs.value(1)
    for char in string:
        send2LCD8(ord(char))

def read_temperature():
    beta = 3950
    series_resistor = 10000
    adc_value = adc.read_u16()
    resistance = series_resistor / (65535 / adc_value - 1)

    # Using the Steinhart-Hart equation to calculate the temperature
    steinhart = resistance / 10000  # (R/Ro)
    steinhart = math.log(steinhart)  # ln(R/Ro)
    steinhart /= beta  # 1/B * ln(R/Ro)
    steinhart += 1.0 / (25 + 273.15)  # + (1/To)
    steinhart = 1.0 / steinhart  # Invert
    steinhart -= 273.15  # Convert to Celsius
    return steinhart

# Main loop
setUpLCD()
#send_string_to_lcd("     DANGER!")
while True:
    temperature = read_temperature()
    print("Temperature:", temperature, "°C")

    if temperature > 45:
        led.on()
        #send_string_to_lcd("Temperature>45C")
        send_string_to_lcd("     DANGER!")
        buzz.duty_u16(3000)
        buzz.freq(3000)
        utime.sleep(2)
        buzz.duty_u16(0)
        utime.sleep(temperature / 1000)
    utime.sleep(1)
    if temperature < 45:
        led.off()
        send_string_to_lcd("SAFE")
        utime.sleep(2)