subscriber.py

import os 
import sys 
import paho.mqtt.client as mqtt 
import RPi.GPIO as GPIO 
import time 
import Adafruit_DHT 
import threading 
 
pid = str(os.getpid()) 
pidfile = "/tmp/3dprinter.pid" 
 
print("init DHT22") 
 
sensor = Adafruit_DHT.DHT22 
pin=23 
 
# voltage 3.5V 
relais_pin=17 
#GPIO.cleanup() 
GPIO.setwarnings(True) 
GPIO.setmode(GPIO.BCM) 
GPIO.setup(relais_pin,GPIO.OUT) 
 
def on_connect(client, userdata, flags, rc): 
    print("Connected with result code " + str(rc)) 
 
    client.subscribe("3dprinter/voltage") 
 
def on_message(client, userdata, msg): 
    #print(str(msg.payload)) 
    if 'true' in str(msg.payload): 
        GPIO.output(relais_pin,0) 
        time.sleep(0.4) 
        print("3d printer voltage on") 
    elif 'false' in str(msg.payload): 
        GPIO.output(relais_pin,1) 
        time.sleep(0.3) 
        print("3d printer voltage off") 
    else: 
        print("no allowed message for 3d printer voltage") 
 
def state_loop(): 
    while True: 
        humidity,temperature = Adafruit_DHT.read_retry(sensor, pin) 
     
        if humidity is not None and temperature is not None: 
            print("Temp={0:0.1f}*C  Humidity={1:0.1f}%".format(temperature, humidity)) 
            client.publish("3dprinter/state", str(temperature)+":"+str(humidity)+":"+str(GPIO.input(relais_pin))) 
        else: 
            print("Failed to get reading. Try again!") 
     
        if GPIO.input(relais_pin) == GPIO.LOW: 
            print("Printer is on") 
        else: 
            print("Printer is off") 
 
        time.sleep(2) 
 
def pidloop(): 
    if os.path.isfile(pidfile): 
        print("exit, subscriber works") 
        sys.exit() 
     
    f=open(pidfile,'w') 
    print("write pid") 
    f.write(pid) 
 
try: 
    client = mqtt.Client() 
    client.on_connect = on_connect 
    client.on_message = on_message 
 
    client.connect("server", 1883, 60) 
     
    thread = threading.Thread(target=state_loop) 
    thread.start() 
 
    thread2 = threading.Thread(target=pidloop) 
    thread2.start() 
 
    client.loop_start() 
    client.loop_forever() 
except KeyboardInterrupt: 
    GPIO.cleanup() 
    os.unlink(pidfile) 
    print("end")