rpi.py

"""
This file is the physical thermostat. It will run in a always True while loop. It will check for button inputs on the physical device, and interact with the system through the Thermostat class.
"""

from thermostat import Thermostat
from time import sleep
# FOR DHT22
import adafruit_dht
import board
# FOR LCD
from signal import signal, SIGTERM, SIGHUP, pause
from rpi_lcd import LCD
# FOR RELAY
import RPi.GPIO as GPIO

def ac(pin, state):
   if state == 'ON':
      GPIO.output(pin, GPIO.LOW)
   elif state == 'OFF':
      GPIO.output(pin, GPIO.HIGH)
   else:
      print("Invalid state for AC")
      return

def heat(pin, state):
   if state == 'ON':
      GPIO.output(pin, GPIO.LOW)
   elif state == 'OFF':
      GPIO.output(pin, GPIO.HIGH)
   else:
      print("Invalid state for Heat")
      return

def fan(pin, state):
   if state == 'ON':
      GPIO.output(pin, GPIO.LOW)
   elif state == 'OFF':
      GPIO.output(pin, GPIO.HIGH)
   else:
      print("Invalid state for Fan")
      return


if __name__ == '__main__':
   t = Thermostat()

   # GLOBAL VARIABLES
   SYSTEM_OPTIONS = ['AC', 'HEAT', 'OFF']
   FAN_OPTIONS = ['ON', 'AUTO']
   SCHEDULE_OPTIONS = ['ON', 'OFF']
   PIN_LIST = {'spare': 4, 'ac': 17, 'heat': 27, 'fan': 22, 
               'system_button': 13, 'fan_button': 6, 'schedule_button': 5 , 'up_button': 23, 'down_button': 24}
   AC_STATUS = 'OFF'
   HEAT_STATUS = 'OFF'

   # Initialize DHT22
   dhtDevice = adafruit_dht.DHT22(board.D16, use_pulseio=False)

   # Initialize 16x2 LCD Display
   lcd = LCD()
   lcd_counter = 1
   lcd_timer = 2

   def safe_exit(signum, frame):
      exit(1)

   signal(SIGTERM, safe_exit)
   signal(SIGHUP, safe_exit)

   # Initialize Relays
   GPIO.setmode(GPIO.BCM)

   GPIO.setup(PIN_LIST['ac'], GPIO.OUT)
   GPIO.output(PIN_LIST['ac'], GPIO.HIGH)
   GPIO.setup(PIN_LIST['heat'], GPIO.OUT)
   GPIO.output(PIN_LIST['heat'], GPIO.HIGH)
   GPIO.setup(PIN_LIST['fan'], GPIO.OUT)
   GPIO.output(PIN_LIST['fan'], GPIO.HIGH)

   # Initialize Buttons
   GPIO.setup(PIN_LIST['system_button'], GPIO.IN, pull_up_down=GPIO.PUD_UP)
   GPIO.setup(PIN_LIST['fan_button'], GPIO.IN, pull_up_down=GPIO.PUD_UP)
   GPIO.setup(PIN_LIST['schedule_button'], GPIO.IN, pull_up_down=GPIO.PUD_UP)
   GPIO.setup(PIN_LIST['up_button'], GPIO.IN, pull_up_down=GPIO.PUD_UP)
   GPIO.setup(PIN_LIST['down_button'], GPIO.IN, pull_up_down=GPIO.PUD_UP)

   # Thermostat Control Loop
   while True:
      # get schedule
      schedule_mode = t.get_schedule_mode().upper()
      schedule = t.get_schedule()

      # get setpoint according to schedule mode setting
      if schedule_mode == 'ON':
         setpoint = t.get_schedule_setpoint()
      elif schedule_mode == 'OFF':
         setpoint = t.get_setpoint()
      else:
         print("Invalid schedule mode")
         continue
      setpoint_str = f'{setpoint} F'

      # get current temp & humidity
      try:
         temperature_c = dhtDevice.temperature
         if temperature_c is None:
            temperature_c = 22.2
         temperature_f = round(temperature_c * (9/5) + 32, 1)
         temperature_f_str = f'{temperature_f} F'
         humidity = dhtDevice.humidity
         # Save to curr_temp.json file
         t.update_temp(temperature_f)
         t.update_humidity(humidity)
      except RuntimeError as error:
         # print(error.args[0])
         print("DHT error")
         continue
      except Exception as error:
         dhtDevice.exit()
         raise error


      # System button pressed
      if GPIO.input(PIN_LIST['system_button']) == GPIO.LOW:
         # change system mode from current to next in SYSTEM_OPTIONS
         sys_old = t.get_system()
         index = SYSTEM_OPTIONS.index(sys_old)
         if index == 2:
            index = 0
         else:
            index += 1
         t.set_system(SYSTEM_OPTIONS[index])
         print(f'System changed from {sys_old} to {SYSTEM_OPTIONS[index]}')
      
      # Fan button pressed
      if GPIO.input(PIN_LIST['fan_button']) == GPIO.LOW:
         # change fan mode from current to next in FAN_OPTIONS
         fan_old = t.get_fan()
         index = FAN_OPTIONS.index(fan_old)
         if index == 1:
            index = 0
         else:
            index += 1
         t.set_fan(FAN_OPTIONS[index])
         print(f'Fan changed from {fan_old} to {FAN_OPTIONS[index]}')

      # Schedule button pressed
      if GPIO.input(PIN_LIST['schedule_button']) == GPIO.LOW:
         # change schedule mode from current to next in SCHEDULE_OPTIONS
         schedule_old = t.get_schedule_mode()
         index = SCHEDULE_OPTIONS.index(schedule_old)
         if index == 1:
            index = 0
         else:
            index += 1
         t.set_schedule_mode(SCHEDULE_OPTIONS[index])
         print(f'Schedule changed from {schedule_old} to {SCHEDULE_OPTIONS[index]}')

      # Up or Down button pressed
      if GPIO.input(PIN_LIST['up_button']) == GPIO.LOW:
         print("Up Button Pressed")
         # set schedule mode to OFF
         t.set_schedule_mode('OFF')
         # increase setpoint by 1
         t.set_setpoint(setpoint+1)
      elif GPIO.input(PIN_LIST['down_button']) == GPIO.LOW:
         print("Down Button Pressed")
         # set schedule mode to OFF
         t.set_schedule_mode('OFF')
         # decrease setpoint by 1
         t.set_setpoint(setpoint-1)

      # get system and fan mode
      system = t.get_system()
      fan_mode = t.get_fan().upper()
      print(f'System: {system} Fan: {fan_mode}')

      # write current temp & setpoint to 16x2 LCD
      lcd.text(f"C:{temperature_f_str}  S:{setpoint_str}", 1)
      if lcd_counter <= lcd_timer:
         lcd.text(f"SYS:{system} FAN:{fan_mode}", 2)
         lcd_counter += 1
      else:
         lcd.text(f"    SCH:{schedule_mode}", 2)
         # reset lcd counter and itterate counter accordingly
         if lcd_counter >= 2*lcd_timer:
            lcd_counter = 1
         else:
            lcd_counter += 1
      
      # ensure opposing system relay is off
      if system == 'AC':
         ac(PIN_LIST['heat'], 'OFF')
      elif system == 'HEAT':
         heat(PIN_LIST['ac'], 'OFF')
      elif system == 'OFF':
         ac(PIN_LIST['ac'], 'OFF')
         heat(PIN_LIST['heat'], 'OFF')
         fan(PIN_LIST['fan'], 'OFF')

      # Fan relay control
      if fan_mode == 'ON':
         fan(PIN_LIST['fan'], 'ON')

      # Too Cold
      if temperature_f < (setpoint-t.deadband):
         # AC off
         if system == 'AC':
            ac(PIN_LIST['ac'], 'OFF')

            # Fan off if Auto
            if fan_mode == 'AUTO':
               fan(PIN_LIST['fan'], 'OFF')

            if AC_STATUS == 'ON':
               # Add entry to data base
               t.add_db_data("AC_OFF", "HEAT_OFF")
               AC_STATUS = 'OFF'

         # Heat on
         elif system == 'HEAT':
            heat(PIN_LIST['heat'], 'ON')

            # Fan on if Auto
            if fan_mode == 'AUTO':
               fan(PIN_LIST['fan'], 'ON')

            if HEAT_STATUS == 'OFF':
               # Add entry to data base
               t.add_db_data("AC_OFF", "HEAT_ON")
               HEAT_STATUS = 'ON'

      # Too Hot
      elif temperature_f > (setpoint+t.deadband):
         # AC on
         if system == 'AC':
            ac(PIN_LIST['ac'], 'ON')

            # Fan on if Auto
            if fan_mode == 'AUTO':
               fan(PIN_LIST['fan'], 'ON')

            if AC_STATUS == 'OFF':
               # Add entry to data base
               t.add_db_data("AC_ON", "HEAT_OFF")
               AC_STATUS = 'ON'

         # Heat off
         elif system == 'HEAT':
            heat(PIN_LIST['heat'], 'OFF')

            # Fan off if Auto
            if fan_mode == 'AUTO':
               fan(PIN_LIST['fan'], 'OFF')

            if HEAT_STATUS == 'ON':
               # Add entry to data base
               t.add_db_data("AC_OFF", "HEAT_OFF")
               HEAT_STATUS = 'OFF'


      sleep(1)
      print(".")