Simple MQTT Tutorial

[sakis]

@RSK umqtt is not part of Pycom's firmware or standard micropython. It is an external Python library, so to be able to use it you need to upload it to your device.

The easiest way to do that is using Pymakr. Another way is using plain FTP (https://docs.pycom.io/pycom_esp32/pycom_esp32/general.html#local-file-system-and-ftp-access).

Please read step 2 again and try to follow the instructions. If you have any problems let us know.

[RSK]

@sakis Thanks!

I have downloaded umqtt.simple.py from https://github.com/micropython/micropython-lib and placed it in /flash/simple.py of the LoPy using FTP.

And trying to connect from my LoPy application:

With Hive settings:

But connect fails with error "bytes index out of range":

Please help to resolve.

Thanks & Regards,
Satish Kumar. R.

[RSK]

Sorry the link i provided is incorrect, downloaded from the below link:
https://pypi.python.org/pypi/micropython-umqtt.simple

And the changes done to line number 57 "self.sock.settimeout(self.timeout)"

Thanks & Regards,
Satish Kumar. R.

[sakis]

@RSK Have you tried using port 1883 instead of 8000?

[RSK]

I am trying in Windows, by default http://www.hivemq.com/demos/websocket-client/
give port number 8000.

If i try to change in the browser to 1883 then socket connection fails in websocket client.

[MrPy]

@RSK , Pretty sure you have a port issue. 1883 should work. For some reason Hive MQ isn't accepting requests on 1883 currently. I will search for another public test broker..

[RSK]

@MrPy Thanks!

Adjusting the timeout period in simple.py is helping to make the setup work consistent.

This might help.

Thanks & Regards,
Satish Kumar. R.

[lcgeldenhuys]

What version of the micropython-umqtt.simple library are you using? I'm trying the latest 1.3.2. It doesn't have the same bug on line 57 anymore, in fact it doesn't seem to use the same timeout mechanism.

I'm not able to connect successfully to the HiveMQ public broker:

Traceback (most recent call last):
File "main.py", line 10, in <module>
File "/flash/lib/umqtt.py", line 74, in connect
OSError: [Errno 113] EHOSTUNREACH

Using:

client = MQTTClient("MQTT_lcg_Client", "broker.hivemq.com", port=1883)
client.settimeout = settimeout
client.connect()

I can pub / sub using the MQTT.fx client on my laptop, and the WiPy is on the same network (I can ping and ftp to WiPy from laptop).

Any ideas?

[pwest]

I'm also using the same apparently current 1.3.2 simple.py file, and having the exact issue described by lcgeldenhuys 3 months ago. Any suggestions on how to get past this?

-Phil

[bucknall]

Hi @pwest,

It might be work checking out https://youtu.be/3NDPSbr5J14?list=PLS09TA19umCOavPeP_FoMHoCuCzjJUWQk, where I talk about MQTT and how to get set up with it.

Currently, the documentation on MQTT that we have online is out of date and I am re-writing it as we speak. I'll post back once it has been published!

Thanks,

Alex

[achide]

Hi,

I'm new with pycom. Maybe it's a stupid question, I would like to know how to import umqtt library.
I've put it in lib folder of sys.path, but when I import this module, it told me no module named 'umqtt'?

[bucknall]

@achide How are you uploading code to your device? Are you using the Pymakr Plugin?

[achide]

@bucknall yes, I use Pymakr.

[livius]

@achide
Pymakr IDE or Pymakr Atom Plugin?
If First then do not use it.

[achide]

@livius
Hi, thanks for reply!
It's Pymakr Atom Plugin I use.
I've copy umqtt.py under lib file. Like this :

Then when I run the code, it shows like that :

What should I do ?

[livius]

@achide
I do not use pymakr
but if i understand screen correctly you put it into
\flash\lib\connections
but you should into
\flash\lib