Bits for an MQTT server from ESP8266

esp8266_mqtt.ino

/*
 Basic ESP8266 MQTT example

 This sketch demonstrates the capabilities of the pubsub library in combination
 with the ESP8266 board/library.

 It connects to an MQTT server then:
  - publishes "hello world" to the topic "outTopic" every two seconds
  - subscribes to the topic "inTopic", printing out any messages
    it receives. NB - it assumes the received payloads are strings not binary
  - If the first character of the topic "inTopic" is an 1, switch ON the ESP Led,
    else switch it off

 It will reconnect to the server if the connection is lost using a blocking
 reconnect function. See the 'mqtt_reconnect_nonblocking' example for how to
 achieve the same result without blocking the main loop.

 To install the ESP8266 board, (using Arduino 1.6.4+):
  - Add the following 3rd party board manager under "File -> Preferences -> Additional Boards Manager URLs":
       http://arduino.esp8266.com/stable/package_esp8266com_index.json
  - Open the "Tools -> Board -> Board Manager" and click install for the ESP8266"
  - Select your ESP8266 in "Tools -> Board"

*/

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// Update these with values suitable for your network.

const char* ssid = "ajfisher";
const char* password = "mrt1ckle";
const char* mqtt_server = "192.168.43.140";
const char* clientname = "ESP-01-CLIENT1234";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];

#define WAIT_PERIOD 1000

#define ONE_WIRE_BUS 2  // DS18B20 pin
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature DS18B20(&oneWire);

void setup() {
  //pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);

  // locate devices on the bus
  Serial.print("Locating devices...");
  DS18B20.begin();
  Serial.print("Found ");
  Serial.print(DS18B20.getDeviceCount(), DEC);
  Serial.println(" devices.");
}

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect(clientname)) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("presence", "hello from mqtt");
      // ... and resubscribe
      //client.subscribe("tempfeed");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}
void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  float temp;
  
  DS18B20.requestTemperatures(); 
  temp = DS18B20.getTempCByIndex(0);
//  Serial.print("Temperature: ");
//  Serial.println(temp);
  
  long now = millis();
  if (now - lastMsg > WAIT_PERIOD) {
    lastMsg = now;
    ((String)temp).toCharArray(msg, 50);
    Serial.print("Publish message: ");
    Serial.println(msg);
    client.publish("tempfeed", msg);
  }
}

mqtt_server.js

'use strict'

// dependencies:
//    npm install mosca


var mosca = require('mosca');

var moscaSettings = {
    host: '0.0.0.0',
    port: 1883,
    http: {
        port: 8002,
        host: '0.0.0.0',
        static: './mqtt/',
        bundle: true,
    },
};

var server = new mosca.Server(moscaSettings);
server.on('ready', () => {
    console.log("MQTT server is ready on port %s", moscaSettings.port);
    console.log("HTTP Server is ready on pott %s", moscaSettings.http.port);
});

server.on('published', (packet, client) => {

    // here we see if a client has published a tempfeed value and if
    // so we augment it with other data.
    if (client != undefined) {
        console.log('%s published a message', client.id, packet.payload.toString());

        if (packet.topic == "tempfeed") {
            let value = packet.payload.toString();
            let time = (new Date()).getTime() / 1000;
            let dp = {
                sensor_id: client.id,
                time: time,
                y: value,
            };
            server.publish({
                topic: 'tempfeed/data',
                payload: JSON.stringify(dp)
            });
        }
    }
});

server.on('clientConnected', (client) => {
    console.log('client has connected', client.id);
});

// fired when a client subscribes to a topic
/**server.on('subscribed', function(topic, client) {
  console.log('subscribed : ', topic);
  if (client != undefined) {
      console.log('subscriber: %s', client.id);
  }
});**/
/**
// fired when a client subscribes to a topic
server.on('unsubscribed', function(topic, client) {
  console.log('unsubscribed : ', topic);
});

// fired when a client is disconnecting
server.on('clientDisconnecting', function(client) {
  console.log('clientDisconnecting : ', client.id);
});

server.on('clientDisconnected', (client) => {
    console.log('client disconnected %s', client.id);
});
**/