Node.js Learning through Making – Build a CPU Sensor

cpu sensor
We are back with our LTM (Learning through Making) tutorials and ready to hit the ground running and write some real Node.js code!  In this series, we will learn about Node.js in the context of creating IoT (Internet of Things) projects.  We will build a “CPU Sensor” in this first project since CPU loading/utilization is a “sensor” we can measure, record, and ultimately stream to other locations.  In future tutorials, we will harness the power of Node.js to interact with physical sensors that live outside of our computing environment. Continue reading

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Using Visual Studio Code with a Raspberry Pi (Raspbian)

Learning through Making (LTM) logoWe’re back with our LTM (Learning through Making) series of Node.js tutorials and we’re gearing up and getting ready to write some code!  We’ve learned how to build a Raspberry Pi from the ground up including Node.js, we’ve created a web server in Node without code, and we’ve even managed to get this web server on the Internet as a cool trick.

So how are we going to write Node.js code? There’s nothing that would stop us from simply jumping onto our RasPi and using the Leafpad text editor or even the nano console-based editor to write our code.  I propose that we use some more robust tools in the form of an IDE (Integrated Development Environment) to help us along in our coding journey.

It turns out that the RasPi 2 and RasPi 3—in spite of the significant CPU/memory boost they offer over their predecessors—will run most IDEs a bit sluggishly and will be frustrating for any serious Node.js work.  I offer here a creative alternative we will use to expedite the software development lifecycle and run the Node.js code natively on the Pi. Continue reading

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Visual Studio Code Jumpstart for Node.js Developers

VS Code iconVisual Studio Code is an amazing, lightweight code editor and works great for Node.js development. I like it so much that I am recommending it for those doing the free Learning through Making (LTM) tutorial series I am creating.  My Using Visual Studio Code with a Raspberry Pi (Raspbian) article is closely coupled to this article; however, this article is intended to help you develop with VS Code whether you are using a RasPi or not.

Now, let’s get started with first things first. This article is geared toward awesome, cutting edge people who want to develop with Node.js and leverage the latest ES6 (ES2015) features rather than being content living in yesteryear.  🙂   Am I resonating with you and describing who you are or who you want to be?  If so, let’s get started. Continue reading

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Make Your Raspberry Pi Web Server Available on the Internet with Node.js

web server imageIn Create a Web Server in Node without any Code, we used the http-server npm module to create a web server and serve up files in record time.  Today I will share a way you can take the web server you built and make it available beyond your local network and on the public Internet.  This is pretty cool trick, but I recommend that you use this with caution as this will open up a hole in your router/firewall when you make your web server available to the world.

Once again, we are using Node.js and so this will work on a variety of platforms.  I am focusing here on making this work in the context of Raspberry Pi which is an amazing little machine for IoT applications and everything else under the sun. Ok, let’s get rolling.

Log into your RasPi from a Windows system by launching a Windows Remote Desktop Connection.  (Hit the Windows key on your keyboard and type Remote Desktop Connection to get started.)  This method of remote connection works since we installed xrdp on the RasPi as part of our Beginners Guide to Installing Node.js on a Raspberry Pi 2. Of course, you can connect the RasPi directly to a monitor/keyboard/mouse or use other remote options such as an X Server and come in through Linux, Mac OS X, etc. too.

After you are in the RasPi, launch a terminal session and type the following:

$ sudo npm install -g localtunnel

This will install the npm package called localtunnel globally so it is available as a command anywhere on the RasPi rather than just in the current directory.  The localtunnel package npm page summarizes the mission of this package well:

localtunnel exposes your localhost to the world for easy testing and sharing! No need to mess with DNS or deploy just to have others test out your changes.

Now that we have localtunnel installed, let’s see what kind of parameters it accepts.  You will notice that we invoke localtunnel with “lt” which is the command that is created as part of the global installation.

$ lt --help
Usage: lt --port [num] <options>

Options:
  -h, --host        Upstream server providing forwarding  [default: "http://localtunnel.me"]
  -s, --subdomain   Request this subdomain
  -l, --local-host  Tunnel traffic to this host instead of localhost, override Host header to this host
  -o, --open        opens url in your browser
  -p, --port        Internal http server port  [required]
  --help            Show this help and exit  [boolean]
  --version         Show version number  [boolean]

We see a very nice, simple help page.  I’m going to use the single-character options (e.g. -p) instead of the long option parameter names (e.g. –port).  Please note that you must use two dashes (–port) when using long option names rather than one dash in order for localtunnel to understand and honor the long option name parameters you are passing.

We first need to get our Web server back up and running so that we can make it available to the world.  Launch a new terminal session (leave the other first terminal session open still) and enter the following commands:

$ cd Public
$ http-server

This will make the index.html file and any other files you have residing in your /home/pi/Public directory available to be served up by the web server.

Next, jump back over to the original terminal session you launched so we can get localtunnel working.  Let’s tunnel through to our web server running on port 8080 and launch the local web browser to view our web server from the outside world.  (You can follow along by reviewing the options that are listed in the help info above.)

$ lt -p 8080 -o

Fantastic!  Upon launching the above command, we are assigned a random subdomain such as http://jxloprztp.localhost.me and we now have our web server available on the real Internet.  Go to another machine besides your RasPi such as a laptop/desktop or cell phone so that you can see for yourself that your website has hit the big time and is available everywhere! 🙂

You can now hit Ctrl-C in the terminal window running localtunnel to break the tunnel connection. Pretty amazing technology, eh?

Local tunnel has some other options. For example, you can choose your own subdomain rather than being assigned a random subdomain.  Let’s try that now:

$lt -p 8080 -s mypizzaweb -o

Assuming nobody is actively using the mypizzaweb subdomain, you can now navigate to it by typing “http://mypizzaweb.localtunnel.me” in your Web browser address bar.

Once again, be sure to hit Ctrl-C in the terminal window running localtunnel to break the tunnel connection.  It’s the wild west out there.

That’s it until next time!

Follow Dave Johnson on Twitter to stay up to date on the latest tutorials and tech articles.

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Right click on Windows folder and open with Visual Studio Code

I’m all about using Visual Studio Code for Node.js development.  It is a lightweight code editor and runs on Windows, Mac OS X, and Linux.  I enjoy it so much that I also use it for Node.js projects on the Raspberry Pi.  To accomplish this, I create a Windows file share on the RasPi as described in my Beginner’s Guide to Installing Node.js on the Raspberry Pi and map a drive on my Windows system to the RasPi.  I am then able to use VS Code to create my Node.js code and jump onto the RasPi to run the actual code.

Anyway, back to our regularly scheduled program…  Today’s topic is aimed at Windows users who are using Visual Studio Code and want to be able to right click on a given folder and launch VS Code.  We’re going to add a right click context menu item to “Open Folder as VS Code Project” since it saves time—and it’s more fun! Continue reading

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Create a Web Server in Node without any Code

Learning through Making (LTM) logoWelcome back!  In a previous tutorial (Beginners Guide to Installing Node.js on a Raspberry Pi), we installed Node.js on a Raspberry Pi. We are now ready to continue our LTM (Learning through Making) tutorial series and build a simple web server without any code.  While this tutorial is geared toward the RasPi, the instructions can be easily mapped over to other platforms such as Windows, Linux, and OS X.  Let’s get started! Continue reading

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