# Imports
from machine import Pin, ADC, I2C
from pico_i2c_lcd import I2cLcd
from time import sleep
from math import log

def main():
  # a tiny sleep to allow the first print to be displayed
  print('Program starting')

  # code below here
  # Variables
  i2c = I2C(0, scl=Pin(5), sda=Pin(4), freq=400000)
  address = 0x27
  rows = 4
  columns = 20
  BETA = 3950
  string1 = ""
  prev_string = ""

  # Pins
  relay = Pin(13, Pin.OUT)
  ntc = ADC(Pin(26))
  pot = ADC(Pin(27))
  lcd = I2cLcd(i2c, address, rows, columns)
  # LCD Reset
  lcd.clear()


  # Main Loop
  while True:
    # Start Delay
    sleep(0.02)

    # Readings
    temp = ntc.read_u16()
    humi = pot.read_u16()

    # Temperature Conversion
    celsius = round(1 / (log(1 / (65535. / temp - 1)) / BETA + 1.0 / 298.15) - 273.15, 2)

    # Humidity conversion to percentage
    humi_percent = round((humi / 65535) * 100, 1)

    # LCD Displaying
    lcd.move_to(0, 0)
    lcd.putstr("Smart Irrigation")
    lcd.move_to(0, 1)
    lcd.putstr(f"Temperature: {celsius}{chr(223)}C")
    lcd.move_to(0, 2)
    lcd.putstr(f"Humidity: {humi_percent}%")
    lcd.move_to(0, 3)
    if humi_percent < 30.0:
      relay.value(1)
      string1 = "Pump: Irrigating"
    else:
      relay.value(0)
      string1 = "Pump: Idle      "
    
    if string1 != prev_string:
      lcd.move_to(0, 3)
      lcd.putstr(string1)
      prev_string = string1

    sleep(5)



if __name__ == "__main__":
    main()