How to get sensor data over TCP/IP in nodejs?

Question

I have a nodejs app with socket.io. To test this, save the below listing as app.js. Install node, then npm install socket.io and finally run on command prompt: node app.

Answer 1

I have a decent hack that is working right now, for which I request the readers to comment on....

---

var net = require('net'),
http = require('http'),
port = 7700,                    // Datalogger port
host = '172.16.103.32',         // Datalogger IP address
fs = require('fs'),
// NEVER use a Sync function except at start-up!
index = fs.readFileSync(__dirname + '/index.html');

// Send index.html to all requests
var app = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.end(index);
});

// Socket.io server listens to our app
var io = require('socket.io').listen(app);

// Emit welcome message on connection
io.sockets.on('connection', function(socket) {
    socket.emit('welcome', { message: 'Welcome!' });

    socket.on('i am client', console.log);
});

//Create a TCP socket to read data from datalogger
var socket = net.createConnection(port, host);

socket.on('error', function(error) {
  console.log("Error Connecting");
});

socket.on('connect', function(connect) {

  console.log('connection established');

  socket.setEncoding('ascii');

});

socket.on('data', function(data) {

  console.log('DATA ' + socket.remoteAddress + ': ' + data);
  io.sockets.emit('livedata', { livedata: data });        //This is where data is being sent to html file 

});

socket.on('end', function() {
  console.log('socket closing...');
});

app.listen(3000);

---

References:

1. Socket.io Website - www.socket.io - Its the buzzword now.
2. TCP Socket Programming
3. Nodejs "net" module
4. Simplest possible socket.io example.