How to subscribe to a MQTT topic

[espruino-discuss]

Posted at 2017-11-20 by Alexander

How to subscribe to a MQTT topic?
ESP sends messages, but does not accept.
code:
var server = "m14.cloudmqtt.com";
var options = {
client_id : "random",
keep_alive: 60,
clean_session: true,
port: 15577,
username: "ciugiy**",
password: "eYV1ivUWk***",
protocol_name: "MQTT",
protocol_level: 4,
};

var mqtt = require("MQTT").create(server, options);
var wifi = require("Wifi");

function onInit() {
wifi.stopAP();
wifi.connect("INGRI", {password: "3hotswf3"}, function(err) { // 192.168.83.196//
//wifi.connect("AndroidAP", {password: "tssu7350"}, function(err) { // 192.168.83.196//
if(err)console.log(err);else console.log("connected!");
console.log(wifi.getIP().ip);

wifi.getStatus(function(ap) {
if(ap.station === 'connected'){

mqtt.on('connected', function() {
print("connect!!!");
       var topic = "test/espruino";
       var message = "hello, world";
       mqtt.publish(topic, message);
});
mqtt.on('publish', function (pub) {
  console.log("topic: "+pub.topic);
  console.log("message: "+pub.message);
});
mqtt.on('disconnected', function() {
  console.log("MQTT disconnected... reconnecting.");
  setTimeout(function() {
  mqtt.connect();
  print("mqtt connect");
 }, 2000);
});
mqtt.connect();
      }
    });
    });

}

wifi.save();
save();

[espruino-discuss]

Posted at 2017-11-20 by Alexander

This is a subscription to the topic :) Learn English!:)

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Posted at 2017-11-20 by @gfwilliams

mqtt.subscribe("test/espruino");?

Also, I've tended to put a leading slash on all the topics I use (eg mqtt.subscribe("/test/espruino");) which might help.

If you want anything beginning with test then you need wildcards: mqtt.subscribe("test/#");

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Posted at 2017-11-20 by Alexander

Is it possible to make a secure connection SSL or TLS?

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Posted at 2017-11-20 by @gfwilliams

Yes - if you buy an Espruino WiFi board, or potentially an ESP32. It isn't possible with the ESP8266 since it doesn't have enough RAM to handle TLS as well as Espruino