thingsboard connection to esp32 using MQTT

Question

I want to connect ESP32 to demo thingsboard using MQTT and I've used umqtt.simple to connect to it but there's a problem. Whenever I try to connect it gives me either this (File "umqtt/simple.py", line 99, in connect), OR (File "umqtt/simple.py", line 57, in connect IndexError: list index out of range), which I believe they are the same. Although when I tried to connect ESP32 to thingspeak (with some edits) it connected, sent and received data very well. So what is the problem?

My code:

import machine
import time
from machine import Pin, PWM
from umqtt.simple import MQTTClient
from time import sleep
import random
import json
import network
#################MQTT###################

def connect():
  username="USER_NAME"
  broker=  "demo.thngsboard.io"
  topic = "v1/devices/me/telemetry"
  client = MQTTClient(username,broker)

  try:
    print("uuuuuuuuuu")
    client.connect()
  except OSError:
    print('Connection failed')
    sys.exit()

  data = dict()
  data["see"] = 15
  data2=json.dumps(data)#convert it to json

  print('connection finished')
  client.publish(topic,data2)
  print("kkkkkkkkkkkkkkkkkk")
  time.sleep(5)
#print("Sending OFF")
connect()

Please note that I've seen that Question on micropython but it didn't fix my problem: https://forum.micropython.org/viewtopic.php?t=4412 also I've seen that question in which he had A similar problem but he solved it without providing the solution: Device not connecting to Thingsboard using MQTT

AND for sure I'm connecting it to the internet.

Answer 1

The problem seems to be, that umqtt from micropython only supports no authentication or user AND password authentication. So I've edited my code as follows:

import machine
import time
from machine import Pin, PWM
from umqtt.simple import MQTTClient
from time import sleep
import random
import json
import network
#################MQTT###################


def connect():
  username="Your_Token"
  broker=  "demo.thingsboard.io"
  topic = "v1/devices/me/telemetry"
  Mqtt_CLIENT_ID = "Client_ID"        # Max. Number is 23 due to MQTT specs
  PASSWORD=""
  client = MQTTClient(client_id=Mqtt_CLIENT_ID, server=broker, port=1883, user=username, password=PASSWORD, keepalive=10000)
  try:
    client.connect()
  except OSError:
    print('Connection failed')
    sys.exit()
  data = dict()
  data["see"] = 15
  data2=json.dumps(data)#convert it to json

  print('connection finished')
  client.publish(topic,data2)
  print("Data_Published")
  time.sleep(5)
#print("Sending OFF")
connect()