client_sub.py - Raspberry Pi Code

import paho.mqtt.client as mqtt
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(18,GPIO.OUT)
sensor1_value = 0
sensor2_value = 0



def on_connect(client, userdata, flags, rc):
   global flag_connected
   flag_connected = 1
   client_subscriptions(client)
   print("Connected to MQTT server")

def on_disconnect(client, userdata, rc):
   global flag_connected
   flag_connected = 0
   print("Disconnected from MQTT server")

# a callback functions
def callback_esp32_sensor1(client, userdata, msg):
    print('ESP sensor1 data: ', msg.payload.decode('utf-8'))
    sensor1_value = int(msg.payload.decode('utf-8'))

    if(sensor2_value>3000 or sensor1_value>0):
        print("LED on")
        GPIO.output(18,GPIO.HIGH)
    else:
        print("LED off")
        GPIO.output(18,GPIO.LOW)

def callback_esp32_sensor2(client, userdata, msg):
    print('ESP sensor2 data: ', str(msg.payload.decode('utf-8')))
    sensor2_value = int(msg.payload.decode('utf-8'))

    if(sensor2_value>3000 or sensor1_value>0):
        print("LED on")
        GPIO.output(18,GPIO.HIGH)
    else:
        print("LED off")
        GPIO.output(18,GPIO.LOW)


def callback_rpi_broadcast(client, userdata, msg):
    print('RPi Broadcast message:  ', str(msg.payload.decode('utf-8')))

def client_subscriptions(client):
    client.subscribe("esp32/#")
    client.subscribe("rpi/broadcast")

client = mqtt.Client("rpi_client1") #this should be a unique name
flag_connected = 0

client.on_connect = on_connect
client.on_disconnect = on_disconnect
client.message_callback_add('esp32/sensor1', callback_esp32_sensor1)
client.message_callback_add('esp32/sensor2', callback_esp32_sensor2)
client.message_callback_add('rpi/broadcast', callback_rpi_broadcast)
client.connect('127.0.0.1',1883)
# start a new thread
client.loop_start()
client_subscriptions(client)
print("......client setup complete............")


while True:
    time.sleep(4)
    if (flag_connected != 1):
        print("trying to connect MQTT server..")