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Node.js and

Raspberry Pi

Raspberry Pi is a small, multi-use computer.

With Node.js you can do amazing things with your Raspberry Pi.

What is the Raspberry Pi?

The Raspberry Pi is a small, affordable, and amazingly capable, credit card
size computer.

It is developed by the Raspberry Pi Foundation, and it might be the most
versatile tech ever created.

Creator Eben Upton’s goal was to create a low-cost device that would improve
programming skills and hardware understanding.

Due to the small size and price of the device, it has become the center of a
wide range of projects by tinkerers, makers, and electronics enthusiasts.

Raspberry Pi and Node.js

The Raspberry Pi has a row of GPIO (General Purpose input/output) pins, and
these can be used to interact in amazing ways with the real world. This tutorial
will focus on how to use these with Node.js.

What Do I Need?

For this tutorial you need a Raspberry Pi. In our examples we use a Raspberry Pi 3,
but this tutorial should work for most versions.

Hardware needed:

Raspberry Pi computer
MicroSD memory card (We recommend a class 10 with 16 GB or higher)
MicroSD to SD memory card adapter (usually included with the MicroSD card)
Micro USB power supply to power the Raspberry Pi (2.5A or greater
recommended)
WiFi/Ethernet Cable connection for the Raspberry Pi (Not needed for
Raspberry Pi 3 as it has built in WiFi)
A working computer with internet and SD memory card reader (used to get the OS
(Operating System) for the Raspberry Pi onto the memory card). In our tutorial
we use a Windows computer for this, but you can use a Mac or Linux computer if
you prefer
HDMI monitor, USB keyboard (we need these only temporarily for the first
boot of the Raspberry Pi)

For later chapters in this tutorial we will use special sensors or devices
that we connect to the Raspberry Pi. We will specify these as special
requirements in the relevant chapters.

If you already have a Raspberry Pi set up with Raspbian, internet and enabled
SSH, you can skip to the step “Install Node.js on Raspberry Pi”.

Write Raspbian OS Image to MicroSD Card

Before we can start using our Raspberry Pi for anything, we need to get a OS
installed.

Raspbian is a free operating system based on Debian Linux, and it is
optimized Raspberry Pi.

Download the latest Raspbian image from https://www.raspberrypi.org/downloads/raspbian/
to your computer.

We use the “LITE” version in our tutorial, since we are setting the Raspberry
Pi up as a headless server (we will connect to it through SSH, without having a
keyboard/display connected to it). You can use whichever version you want, but
this tutorial is written with the “LITE” version as its focus.

Insert the MicroSD memory card in your computer (via the SD adapter if
needed).
Open File Explorer to verify that it is operational.

Etcher is a program for flashing images to memory cards. Download and
install Etcher from: https://etcher.io/

Launch Etcher:

Launch Etcher

Click “Select image” button and find the Raspbian zip file that
you downloaded.

Click the “Select drive” button and specify the memory card as the target location.

Click the “Flash!” button to write the image to the memory card.

After Etcher is finished writing the image to the memory card, remove it from your computer.

Set up Your Raspberry Pi

To get the Raspberry Pi ready to boot we need to:

Insert the MicroSD memory card into the Raspberry Pi
Connect the USB keyboard
Connect the HDMI cable
Connect the USB Wi-Fi adapter (or Ethernet cable). Skip this step if you
are using a Raspberry Pi 3
Connect the micro USB power supply
The Raspberry Pi should now be booting up

When the Raspberry Pi is finished booting up, log in using username: pi and password: raspberry

Set Up Network on the Raspberry Pi

If you will use a Ethernet cable to connect your Raspberry Pi to the
internet, you can skip this step.

For this section we will assume you have a Raspberry Pi 3, with built in
WiFi.

Start by scanning for wireless networks:

pi@raspberrypi:~ $
sudo iwlist wlan0 scan

This will list all of the available WiFi networks. (It also confirms that
your WiFi is working)

Now we need to open the wpa-supplicant file, to add the network you want to
connect to:

pi@raspberrypi:~ $ sudo
nano /etc/wpa_supplicant/wpa_supplicant.conf

This will open the file in the Nano editor. Add the following to the bottom
of the file (change wifiName and wifiPassword with the actual network name and
password):

network={
ssid=”wifiName”
psk=”wifiPassword”
}

Press “Ctrl+x” to save the code. Confirm with “y“, and confirm the name with “Enter“.

And reboot the Raspberry Pi:

pi@raspberrypi:~ $ sudo reboot

After reboot, log in again, and confirm that the WiFi is connected and working:

pi@raspberrypi:~ $ ifconfig wlan0

If the WiFi is working propery, the information displayed should include an
IP address, similar to this:

inet addr:192.168.1.50

Write down that IP address, as we will use it to connect to the Raspberry Pi
via SSH.

Enable SSH, Change Hostname and Password

Now your Raspberry Pi is connected to the internet, it is time to enable SSH.

SSH allows you up use the Raspberry Pi without having a monitor and keyboard
connected to it.

(You will need a SSH client for this on your non-Raspberry Pi computer. We use
PuTTY for windows)

Open the Raspberry Pi Software Configuration Tool:

pi@raspberrypi:~ $ sudo raspi-config

You should see a menu like this:

raspi-config Main Screen

Select option 5 Interfacing Options:

raspi-config Main Screen

Select option P2 SSH, to activate SSH:

raspi-config Main Screen

Confirm with YES, to activate SSH:

raspi-config Main Screen

SSH is now enabled, and you should be in the main menu again.

Select 1 Change User Password, and follow the instructions to change the password. Choose a secure password, but something you will remember:

raspi-config Main Screen

After you have finished changing the password, you should be back in the main menu.

Select 2 Hostname, and follow the instructions to change the hostname:

raspi-config Main Screen

After you have finished changing the hostname, you should be back in the main menu.

Now we will close the menu and save the changes:

raspi-config Main Screen

When selecting Finish, you will get the option to reboot. Select Yes to reboot the Raspberry Pi.

raspi-config Main Screen

You can now unplug the monitor and keyboard from the Raspberry Pi, and we can log in using out SSH client.

Open PuTTY, type in the IP address for your Raspberry Pi, and click Open:

raspi-config Main Screen

You should now see a command line like this: (we used w3demopi as our hostname)

pi@w3demopi:~ $

You are now able to run your Raspberry Pi in “Headless-mode”, meaning you do not need a monitor or keyboard. And if you have a WiFi connection, you do not need a ethernet cable either, just the power cable!