pi-temp.js

"use strict";

//hardware modules
const Raspi = require("raspi-io");
const five = require("johnny-five");
const board = new five.Board({
  io: new Raspi()
});

//networking modules
const http = require("http");
const sockjs = require("sockjs");

const wsClients = [];
let currentTemperature = null;

function wsBroadcast(msg) {
  wsClients.forEach(client => {
    client.write(JSON.stringify(msg));
  });
}

const wsServer = sockjs.createServer();

wsServer.on("connection", (conn) => {
  wsClients.push(conn);
});

//gets called on HTTP requests
function onRequest(req, res) {
  res.end(JSON.stringify({
        temperature: currentTemperature
  }));
}

const httpServer = http.createServer(onRequest).listen(8080);

wsServer.installHandlers(httpServer, { prefix: "/stream" });

board.on("ready", function() {
  const multi = new five.Multi({
      controller: "MPL3115A2",
      elevation: 492
  });

  multi.on("change", function() {
    currentTemperature = this.temperature.celsius;
    console.log(this.temperature.celsius, this.barometer.pressure, this.altimeter.meters);
 
     wsBroadcast({
       temperature: this.temperature.celsius,     
       ts: Date.now()     
     });
  });
});