Paho mqtt publish topic failure

Question

Recently I tried to publish and subscribe message through AWS IOT service.

Here is how I processed it:

Subscribe to topic "Sensor/+/reading" (Subscribe.py)
Publish the data to topic "Sensor/livingroom/reading" (Publish.py)

However, every time I published the data to AWS IOT MQTT server, my script for subscribing reconnected to the MQTT server and received no data from remote.

Here are my Subscribe.py script:

import sys                                 
import ssl
import paho.mqtt.client as mqtt 
import time

def on_connect(mqttc, obj, flags, rc):
    if rc==0:
        print ("Connection status: successful")
    elif rc==1:
        print ("Connection status: Connection refused")
    mqttc.subscribe("Sensor/+/reading", qos=1)

def on_subscribe(mqttc, obj, mid, granted_qos):
    print("Subscribed: "+str(mid)+" "+str(granted_qos)+"data"+str(obj))

def on_message(mqttc, obj, msg):
    print("TOPIC: "+msg.topic+"| Data Received: "+str(msg.payload))


mqttc = mqtt.Client(client_id="Yun")

mqttc.on_connect = on_connect 
mqttc.on_subscribe = on_subscribe

mqttc.tls_set("root-CA.crt",
                certfile="64bc41eab8-certificate.pem.crt",
                keyfile="64bc41eab8-private.pem.key",
                tls_version=ssl.PROTOCOL_TLSv1_2, 
                ciphers=None)

mqttc.connect("AWS Thing endpoint",port = 8883)

mqttc.loop_forever()

And here is my Publish.py script:

import sys                                 
import ssl
import json
import time
import paho.mqtt.client as mqtt

jsonstr = '{"DeviceId":0,"Readings":[{"label":"Light","data":223},{"label":"Motion","data":245}]}'

jsonReading = json.loads(jsonstr)

payloadJson = {}
payloadJson['state'] = {}
payloadJson['state']['desired'] = jsonReading

print payloadJson

def on_publish(mosq, obj, mid):
    print("mid: "+str(mid))

def on_connect(mqttc, obj, flags, rc):
    if rc==0:
        print ("Connection status: successful")
    elif rc==1:
        print ("Connection refused")
    return

def on_disconnect(client, userdata, rc):
    print("disonnected")

mqttc = mqtt.Client(client_id="Yun")


mqttc.on_publish = on_publish
mqttc.on_connect = on_connect
mqttc.on_disconnect = on_disconnect

mqttc.tls_set("root-CA.crt",
                certfile="64bc41eab8-certificate.pem.crt",
                keyfile="64bc41eab8-private.pem.key",
                tls_version=ssl.PROTOCOL_TLSv1_2, 
                ciphers=None)

mqttc.connect("AWS iot things endpoint",8883)

mqttc.loop_start()
while True:
    mqttc.publish("Sensor/livingroom/reading", json.dumps(payloadJson) , qos = 1)
    time.sleep(10)

Pringles Pringles · Accepted Answer · 2016-01-23T06:50:37

Solved! One AWS iot Thing cannot connect with two things(connections). Just adding one more thing in AWS iot for extract connection then the scripts will works well.

Paho mqtt publish topic failure

2 Answers