Long-range Sub-GHz wireless mesh networks have become essential for modern communication, particularly in remote areas where traditional infrastructure is impractical or impossible. By utilising lower frequencies (typically below 1 GHz), Sub-GHz networks can achieve remarkable range, low power consumption, and the ability to penetrate obstacles such as buildings and dense forests.

These characteristics make Sub-GHz mesh networks ideal for applications in IoT, outdoor communication, emergency response, and industrial networks. But with numerous technologies now available, choosing the right one for your needs can be challenging.

In the first two parts of this series, we explored why community telecoms matter and how resilient mesh networks can save lives during emergencies. Now comes the question I’m asked most often: “That sounds great, but how do I actually build one?”

This is the knowledge I wish I’d had when I started.

If my journey from those early Austrian tele-working centres to deploying mesh networks across remote Australian properties has taught me anything: the hardest part isn’t the technology—it’s overcoming the psychological barrier between “consumer” and “creator.” We’ve been conditioned to believe telecommunications infrastructure is something large corporations build, not something communities can create themselves.

As the convener for the Adelaide community of The Things Network, I am frequently setting up Multitech Conduit Gateways. Depending on your PC or notebook hardware you might have some problems with the Exar USB-UART driver on Linux.

Here are the steps to getting this unit setup from an Ubuntu (should work for any other Linux distro) machine.

lsusb

Should show something like this:

Bus 002 Device 006: ID 04e2:1410 Exar Corp. XR21V1410 USB-UART IC

Installing VirtualBox is getting increasingly painful on Ubuntu due to the problems with UEFI Secure Boot and the VirtualBox kernel modules. Another reason for an alternative is that running VirtualBox VM’s completely in the background is not as straightforward as it could be.

From the available alternatives I looked into (VMWare, Xen & KVM) it was KVM that fitted my needs (casual VM usage with mostly headless VM’s for testing purposes). Main reasons:

Having just wasted a few hours on getting this Java software running on Linux I am documenting this for future reference and hopefully saving other LoRa / TTN folks some time.

Prerequisites

Install a Java JDK + JavaFX. This should work with the default OpenJDK 8 or 9 which comes as part of the Ubuntu repositories. I ended up installing Oracle JDK 8 as well as I thought the error might be related to OpenJDK.

Install XScreenSaver and remove Gnome default

sudo apt remove gnome-screensaver
sudo apt install xscreensaver xscreensaver-gl xscreensaver-gl-extra

Run the Screensaver UI and configure

In the “Advanced” section enter your Flickr RSS URL in “Choose Random Image”

https://api.flickr.com/services/feeds/photos_faves.gne?id=YOURFLICKRUSERID #replace with your Flickr User ID

Create a systemd user service to autostart

mkdir -p ~/.config/systemd/user/
vim ~/.config/systemd/user/xscreensaver.service

[Unit]
Description=XScreenSaver
[Service]
ExecStart=/usr/bin/xscreensaver -nosplash
[Install]
WantedBy=default.target

Start and enable systemd user service

systemctl --user enable xscreensaver
systemctl --user start xscreensaver

To copy the settings (including RSS URL) onto other PC’s or re-install it might be a good idea to backup or copy the contents of ~/.xscreensaver

If you are using the GUI (Raspian full download) and want to connect your RPi Zero to a keyboard and monitor there are probably easier ways to do this. These notes are for people that want to use a headless (no monitor and GUI) setup ready to connect to your RPi after first boot via SSH from another terminal.

“Raspberry Pi Zero W” (CC BY-SA 2.0) by lespounder

EDIT [2018-06-05]: I have updated the code with the Firmware 1.18.+ releases. The code is available at our Growing Data Foundation Github.

These notes are to assist Australian IoT enthusiasts to get started in connecting a LoPy to The Things Network as it is unfortunately (not yet) straight forward to make them work with the current AU-915 TTN Channel plans. As the initiator of the local Adelaide Community of The Things Network I have been experimenting with a number of devices to connect sensors to #TTNADL. One of my personal favourites is the Pycom LoPy as a nice middle-ground between capabilities and technical complexity.

Since Synology (despite requests) still has not added DNS Made Easy as a listed provider (despite listing some really obscure services – go figure!) here is the steps to add a custom provider.

DNS Made Easy Setup

Create a new A-Record

1. Set the name
2. Set the IP (initial – any valid IP)
3. Tick the “Dynamic DNS” tickbox
4. Enter your chosen Dynamic DNS Password
5. Save the new record

When saving the record you will see a “Dynamic DNS ID” – note down this number. This will become the hostname on the Synology setup.

Upgrade or install SANE backends

Since the version of SANE in the Ubuntu 16.04LTS repos is not working for this scanner you either need to install from sources (see this blog) or from this PPA.

sudo add-apt-repository ppa:rolfbensch/sane-git

sudo apt update sudo apt install sane-backends tesseract-ocr gscan2pdf`

Security

Add yourself to the ‘scanner’ group to be able to use the scanner.

sudo usermod -a -G scanner USERNAME

Checking SANE

Check for the libsane version (needs to be at least libsane.so.1.0.26 not libsane.so.1.0.25 which is in the Ubuntu repos)

Since there is now a supported Raspbian version without GUI and other unneeded add-ons available as Raspbian Lite the need to use other installers (with sometimes some downsides) is now not a necessity anymore. Below is a list of steps I like to perform before using them for any purpose as my Standard Operating Environment.

Download Raspbian Lite

Download link: https://www.raspberrypi.org/downloads/raspbian/

Write to SD Card

dd bs=4M if=2016-05-27-raspbian-jessie-lite.img of=/dev/sdb

Boot RPi

Default login details are
UID: pi
PWD: rasbperry

Whilst there is a .DEB installer to download from the GoHugo sites I get all matter of warnings that the package is of bad quality and I am not comfortable to run these kinds of installers.

I rather install from sources in this case which is very straight forward since the main dependencies (largely GO) are in the Ubuntu main repositories.

Install dependencies

sudo apt-get install golang git mercurial python-pygments