var app = require('http').createServer(handler),
io = require('socket.io').listen(app),
fs = require('fs'),
url = require('url'),
SerialPort = require('serialport').SerialPort,
// initialize serialport using the COM5 serial port
// remember to change this string if your arduino is using a different serial port
sp = new SerialPort('COM5', {
baudRate: 115200
}),
// this var will contain the message string dispatched by arduino
arduinoMessage = '',
/**
* helper function to load any app file required by client.html
* @param { String } pathname: path of the file requested to the nodejs server
* @param { Object } res: http://nodejs.org/api/http.html#http_class_http_serverresponse
*/
readFile = function(pathname, res) {
// an empty path returns client.html
if (pathname === '/')
pathname = 'client.html';
fs.readFile('htmlarduino/client/' + pathname, function(err, data) {
if (err) {
console.log(err);
res.writeHead(500);
return res.end('Error loading client.html');
}
res.writeHead(200);
res.end(data);
});
},
/**
*
* This function is used as proxy to print the arduino messages into the nodejs console and on the page
* @param { Buffer } buffer: buffer data sent via serialport
* @param { Object } socket: it's the socket.io instance managing the connections with the client.html page
*
*/
sendMessage = function(buffer, socket) {
// concatenating the string buffers sent via usb port
arduinoMessage += buffer.toString();
// detecting the end of the string
if (arduinoMessage.indexOf('\r') >= 0) {
// log the message into the terminal
// console.log(arduinoMessage);
// send the message to the client
socket.volatile.emit('notification', arduinoMessage);
// reset the output string to an empty value
arduinoMessage = '';
}
};
// creating a new websocket
io.sockets.on('connection', function(socket) {
// listen all the serial port messages sent from arduino and passing them to the proxy function sendMessage
sp.on('data', function(data) {
sendMessage(data, socket);
});
// listen all the websocket "lightStatus" messages coming from the client.html page
socket.on('lightStatus', function(lightStatus) {
sp.write(lightStatus + '\r', function() {
// log the light status into the terminal
console.log('the light should be: ' + lightStatus);
});
});
});
// just some debug listeners
sp.on('close', function(err) {
console.log('Port closed!');
});
sp.on('error', function(err) {
console.error('error', err);
});
sp.on('open', function() {
console.log('Port opened!');
});
// L3T'S R0CK!!!
// creating the server ( localhost:8000 )
app.listen(8000);
// server handler
function handler(req, res) {
readFile(url.parse(req.url).pathname, res);
}
