Hello, world for Iot systems and coap

Iot system and coap Hello, world

We will give a brief introduction to coap and IOT systems in the previous article (PS: coap and IOT system). Then we will try the application of coap protocol.

Coap Application

Before getting started, we need to access coap: // localhost/, so we need to install a Firefox plug-in copper.

Firefox Copper

: Https://addons.mozilla.org/en-US/firefox/addon/copper-270430/

For test, we can access coap: // vs0.inf. ethz. ch: 5683/

Node coap

Node-coap is a client and server library for coap modelled after the HTTP module.

Node-coap is a library of clients and servers used for coap module modeling. Create a package. JSON file and add our library

{    "dependencies":{        "coap": "0.7.2"    }}

Then execute

npm install

We can install our dependencies.

Coap example

So we can create such an app. js file.

const coap        = require(‘coap‘)    , server  = coap.createServer()server.on(‘request‘, function(req, res) {  res.end(‘Hello ‘ + req.url.split(‘/‘)[1] + ‘\n‘)})server.listen(function() {  console.log(‘server started‘)})

Then execute

node app.js

We can access it in a browser, but now there is nothing. Then we create a client-side JS and run it.

const coap  = require(‘coap‘)     , req   = coap.request(‘coap://localhost/World‘)req.on(‘response‘, function(res) {  res.pipe(process.stdout)})req.end()

You can output

Hello World

In this way, we can use the coap protocol to create a service, and then we should use it to create more things, such as generating JSON data and restful.

Others

Iot system coap in progress

Https://github.com/gmszone/iot-coap