relay/relay.py

#!/usr/bin/python3

import RPi.GPIO as GPIO
import time
import requests
import platform
import datetime

relay_pin = 11
#GPIO.setmode(GPIO.BCM) # GPIO numbers instead of board numbers.
GPIO.setmode(GPIO.BOARD)
GPIO.setup(relay_pin, GPIO.OUT)

device_id = platform.node()  # For servers logs.

def get_api_url():
    # Yes, I know I could do this better. Stop moaning.
    if (device_id == "gallery1"):
        return "http://ritherdon.abbether.net/api/readings/latest/1"
    elif (device_id == "gallery2"):
        return "http://ritherdon.abbether.net/api/readings/latest/2"

# Make sure this is valid.
# api_url = "http://ritherdon.abbether.net/api/readings/add/1"
api_url = get_api_url() # Saves having to do the if-check every call.

def main():
    try:
        while True:
            # Make sure the U.R.L. is valid.
            s = requests.Session()
            r = s.get(api_url, timeout=5)
            # print(r.status_code) # For testing.
            data = r.json()
            # print(data) # For testing.
            the_reading = data.get("reading")
            # print(the_reading) # For testing.
            if (device_id == "gallery1"):
                if (the_reading > 38):
                    # print(f"[INFO: FACTORY1] Light is on -- {the_reading}.")
                    GPIO.output(relay_pin, GPIO.HIGH)
                else:
                    # print(f"[INFO: FACTORY1] Light is off -- {the_reading}.")
                    GPIO.output(relay_pin, GPIO.LOW)
            elif (device_id == "gallery2"):
                if (the_reading > 48):
                    # print(f"[INFO: FACTORY2] Light is on -- {the_reading}.")
                    GPIO.output(relay_pin, GPIO.HIGH)
                else:
                    # print(f"[INFO: FACTORY2] Light is off -- {the_reading}.")
                    GPIO.output(relay_pin, GPIO.LOW)
    except KeyboardInterrupt:
        print("[INFO] KEYBOARD INTERRUPT: quitting program.")
    except requests.exceptions.ConnectionError:
        pause = 60
        time.sleep(60)
        print(f"[WARNING] MAX. REQUESTS EXCEEDED: Pausing requests for {pause} seconds...")
        pass
    except requests.exceptions.Timeout:
        t_stamp = datetime.datetime.now()
        print(f"[WARNING] TIMEOUT EXCEPTION: Request timed-out at {t_stamp}.")
        time.sleep(60)
        pass
    except Exception as e:
        print(f"[ERROR] GENERAL EXCEPTION: {e}")
    finally:
        print("[INFO] Terminating relay.py...")
        print("[INFO] Cleaning up GPIO before closing...")
        GPIO.cleanup()

if __name__ == "__main__" :
    main()