from machine import Pin, SoftI2C, ADC
from math import log
from i2c_lcd import I2cLcd 
from time import sleep

ADC_temp = ADC(Pin(2)) # pin 2 will be used to monitor temperature
ADC_light = ADC(Pin(15)) # pin 15 will be used to monitor light level

lcd1_address = 0x27
lcd2_address = 0x26

i2c = SoftI2C(scl = Pin(22), sda = Pin(23), freq = 400000)

lcd1 = I2cLcd(i2c, lcd1_address, 2, 16)  # the display has 2 rows and 16 columns
lcd2 = I2cLcd(i2c, lcd2_address, 2, 16)  # the display has 2 rows and 16 columns
lcd1.backlight_off()

my_char = bytearray([
    0b00100,
    0b10101,
    0b10101,
    0b11111,
    0b00100,
    0b00100,
    0b00100,
    0b00100
])
lcd2.custom_char(0, my_char)  # store the new character at location 0
lcd2.putchar(chr(0))  # display character stored at index 0 in LCD memory​

def get_temperature():
    beta = 3950 # beta coefficient of the thermistor being used
    kelvin = 273.15 # value of temperature in Kelvin at zero Celsius

    temp_value = ADC_temp.read()
    # Convert the analog value into temperature
    temperature_in_celsius = 1 / (log(1 / (4096 / temp_value - 1))/beta + 1.0 / 298.15) - kelvin
    temperature_in_celsius=round(temperature_in_celsius,1)
    return temperature_in_celsius

def get_lux():
    GAMMA = 0.7
    RL10 = 50

    light_value = ADC_light.read()
    # Convert the analog value into an approximate lux value
    voltage = light_value / 4095 * 5
    resistance = 2000 * voltage / (1 - voltage / 5);
    lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA))
    lux = int(lux)
    return lux


while True:
    
    lcd1.move_to(0,0)
    temp_reading  = get_temperature()
    lcd1.putstr('Temp is: ') # print to first LCD display
    lcd1.putstr(str(temp_reading)) 
    lcd1.putstr('   ') 

    lcd2.move_to(0,0)
    lux_reading = get_lux()
    lcd2.putstr(str(lux_reading)) # print to second LCD display
    lcd2.putstr(' Lux      ') 

    if lux_reading<1000:
        lcd2.move_to(3, 1)  # move cursor to column 5 and row 1​
        lcd2.putchar(chr(0)) # print Trident at RAM display storage location 0
        lcd1.backlight_on()
    else:
        lcd2.move_to(3, 1)  # move cursor to column 5 and row 1​
        lcd2.putstr(' ') 
        lcd1.backlight_off()