A few months ago, I started to build a communications network on a farm in the eastern Free State of South Africa. The farm is very remote, about 30km from the closest small town, 20 minute drive from the nearest tar road, and quite large, at over 20 square km in size. Only a single MTN tower on a high mountain provides cellular reception over the whole valley, and in the event that the tower goes down, usually due to battery theft (theft is common in remote areas, and often occurs on nights with a full moon, sometimes called a poachers moon), means the whole area wont have any connectivity to communicate. In an emergency situation, they dont necessarily need the internet or the ability to communicate externally - the most important requirement was an (independent) network that allowed them to communicate locally between the different residents and houses on the farm, and perhaps other neighboring farmers. We briefly considered a few options:

• Ham Radio - they already had a ham radio setup in one of the houses, but it was not practical for each house across the farm to each have their own ham radio to communicate between the houses.
• Satellite Messengers - there a number of satellite messenger devices on the market, but quite expensive (starting at about R6000)
• LoRa - as the title suggested, we decided to go with LoRa, which is a low-power, long-range radio technique and devices, and together with Meshtastic software, enables you to use inexpensive LoRa radios as a long range off-grid communication platform in areas without existing or reliable communications infrastructure. Meshtastic is all about sending small text messages, and does not cater for voice, video or apps. Its just basic text messages using inexpensive LoRa devices that will create a mesh-network across the whole farm, allowing the different remote houses to communicate with each other.

Getting Started with Lora

There are loads of LoRa and Meshtastic content on the internet, but for South African specific guides, the most comprehensive is this article on GadgeteerZA. It covers everything you need to know: how to get started, what to buy and from where, and how to set it all up. This post is this my review of what we managed to accomplish thus far.

To get started, we decided to start with two devices to test:

Meshtastic supports multiple LoRa manufacturers and devices: Rak WisBlock, LilyGo, Heltec, RaspberryPi, and bunch of other smaller ones. We used the Heltec LoRA 32 V3 devices, with large Yetnorson 8db antennas. The Heltec devices were ordered directly from Heltec in China, and were delivered with-in two weeks. The downside is obviously the delivery costs, plus additional costs you will need to pay to let it past SARS once it lands here in SA. I’ve since found that MicroRobotics stocks the same Heltec 32 S3 devices for about R500, which works out cheaper due to no import costs.

We chose two locations on the farm 2.8 km apart. One was on a high point on an existing house, and the other was deeper in the valley at the base of the mountain, but with line of sight between the two

We successfully managed to get very good signal between the two points, and decided to proceed with the full network build. These two devices would hopefully later on form the core nodes of the Meshtastic network. Meshtastic has different roles that can be configured for each device in the network: the idea being that the devices that each resident on the farm would have would be set to CLIENT, while these core nodes would perhaps be set to REPEATER or ROUTER. This video from The Comms Channel describes the roles well.

Testing more devices

We then looked at the personal devices used by residents: used in the homes, and/or carried around the farm. For this, I decided to try one of each of these, with the idea being that once we have them in-hand and tested them, we will know what to purchase in bulk for residents on the farm.

In total, it came to about R10K for those eight devices. There were a few lessons learned though:

• Amazon.com (from the US, not the local SA store) said it delivered the Lilygo T Echo, but I hadn’t recieved it, so they refunded me.
• For the Pi, I ordered the wrong device, as Meshtastic only supports the Waveshare Hats with SPI (not UUART which is what I bought). Instead, I should have gotten this one for Pi 3/4/5/Zero, or this one for Pico (also available rom PiShop)
• Even though the Lilygo T-Keyboard T-Deck has a keyboard so it can operate stand-alone without a phone to run the Meshtastic app, it does’nt include a case and battery. I have’nt found any cases locally here in SA.

What I realised once I had them in hand, is that these are not consumer-ready devices like cellphones, that just work out of the box. They need to be first flashed with the Mesthtastic software, lack batteries and cases, and the cases are just really pieces of plastic that dont really protect the devices. The Heltec Capsule has some promise though, as it includes a battery and decent case.

Building a solar node

We now needed another node on top of the mountain, to cover the whole valley below. For this, we would need a solar-powered device, as the top of the mountain does not have any power. Again, the Comms Channel provides details on how to build a solar-powered device, and even sells one on Etsy (which unfortunately does not deliver to SA). So I decided to build my one, using the HelTec Mesh Node T114, due to it having inputs for both battery and solar.
Additionally, I also tried the RAKwireless WisBlock, which also has power inputs for battery and solar, but is much more power efficient. Locally, I see that Digikey stocks Wisblock, but only the Core module, but not the Base module.

MicroRobotics didn’t have stock of the Yetnorson 8db antenna, so this time I got a MikroTek 6.5db antenna from Scoop instead. For other antenna locally, these may be options:

• https://rf-design.co.za/product/ant-868-ob-nm/
• https://otto-wireless-solutions.myshopify.com/collections/crypto-mining/products/cry868-11db-omn-lora-868mhz-outdoor-omni-antenna-11b

In the next post, I will update once this solar node is deployed.