Assignment07

Considering function setTimeout

In this example consider the function setTimeout. setTimeout sets a timer which executes a function or specified piece of code

once after the timer expires. In our case, we will put pin 13 to LOW after 1000ms:

    board.digitalWrite(13, board.HIGH); // write high on pin 13

    timer1 = setTimeout(function () {board.digitalWrite(13, board.LOW);}, 1000);

Clearing the timer:

    clearTimeout(timer1);

var http = require("http").createServer(handler); // on req - handler - function to handle events

var io = require("socket.io").listen(http); // socket library

var fs = require("fs"); // variable for file system for providing html

var firmata = require("firmata");

console.log("Starting the code");

var board = new firmata.Board("/dev/ttyACM0", function(){

    console.log("Connecting to Arduino");

    console.log("Activation of Pin 13");

    board.pinMode(13, board.MODES.OUTPUT); // pin13 as out

});

// we should define handler function which is an argument in the first line

// to specify how events are handled

// handler is similar function as in example01.js -> http.createServer(function(req, res){...

function handler(req, res) {

    fs.readFile(__dirname + "/assignment07.html",

    function (err, data) {

        if (err) {

            res.writeHead(500, {"Content-Type": "text/plain"});

            return res.end("Error loading html page.");

    res.writeHead(200);

    res.end(data);

})

var timer1;

http.listen(8080); // server will listen on port 8080

io.sockets.on("connection", function(socket) {

    socket.on("commandToArduino", function(commandNo){

        if (commandNo == "1") {

            board.digitalWrite(13, board.HIGH); // write high on pin 13

        if (commandNo == "0") {

            board.digitalWrite(13, board.LOW); // write low on pin 13

});

    socket.on("blinkOn", function(){

    board.digitalWrite(13, board.HIGH); // write high on pin 13

    timer1 = setTimeout(function () {board.digitalWrite(13, board.LOW);}, 1000);

});

    socket.on("blinkOff", function(){

    board.digitalWrite(13, board.LOW);

        clearTimeout(timer1);

});

});

<!DOCTYPE html>

<meta charset = utf8>

<html>

<head>

    <title>Example with buttons</title>

</head>

<body>

<button id="buttonOn" style="width: 80px;" onClick="on()">On</button>

<button id="buttonOff" style="width: 80px;" onClick="off()">Off</button>

<br>

<button id="buttonBlinkOn" style="width: 80px;" onClick="blinkOn()">B On</button>

<button id="buttonBlinkOff" style="width: 80px;" onClick="blinkOff()">B Off</button>

<br>

<script type="text/javascript" src="/socket.io/socket.io.js"></script>

<script type="text/javascript">

var socket = io.connect("192.168.254.133:8080"); // connect via socket

function on () {

    socket.emit("commandToArduino", 1);

function off () {

    socket.emit("commandToArduino", 0);

function blinkOn () {

    socket.emit("blinkOn");

function blinkOff () {

    socket.emit("blinkOff");

</script>

</body>

</html>

The gui should look like this (we use style on buttons: style="width: 80px;"):

Page updated

Google Sites

Report abuse