Debugging MQTT

[espruino-discuss]

Posted at 2021-05-14 by DavidM

Hi, am struggling to get MQTT working on ESP8266.
I have numerous actual Espruinos (eg Espruino Wifi), and this code runs fine:

const mqtt = require("tinyMQTT").create('.... url of local hivemq server ...');
mqtt.on('error', function(err){console.log(err)})
mqtt.on('connected', function(){console.log('connected')})

var wifi = require("Wifi");
wifi.connect("...", {password:"...."}, function(){
  console.log("wifi connected");
  mqtt.connect();
});
wifi.stopAP();

Am able to connect to the MQTT server fine with a real Espruino, but with ESP8266 I get nothing, not even an error.

This happens with the official MQTT library and tinyMQTT - work fine on Espruino WiFi, fails on ESP8266.

Question: how to debug this and figure out what's wrong?

David

[espruino-discuss]

Posted at 2021-05-14 by @MaBecker

I suggest to verify Wifi. Have a look at this snippet http://www.espruino.com/EspruinoESP8266#wifi

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Posted at 2021-05-15 by @MaBecker

Question: how to debug this and figure out what's wrong?

You can type mqtt in left side of the WebIDE to get details about the status.

Edit:

Sample output for not connected to the broker:

>mqtt
={
      svr: "test.mosquitto.org",
      prt: 1883, ka: 60, usr: undefined, pwd: undefined, cn: 0,
      ri: 2000, wt: undefined,
      wp: ""
 }
> 

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Posted at 2021-05-15 by @MaBecker

Readme for tinyMQTT has been update.

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Posted at 2021-05-17 by @allObjects

Running an Espruino with a ESP8266 connected for WiFi (Any Espruino and a UART connected ESP8266 for WiFi communication only, including an Espruino-Wifi) is different from actually running all on an ESP8266 or ESP32: for latter, the separation and store and forward type of communication / buffering is missing, and in case of the ESP8266, the processing resources become quickly an issue: JS (application) execution streaks can keep the single processor busy only for a limited time, after that, ESP8266 Wifi stack has to get the control otherwise it 'browns out'... restarts.