The near-instantaneous transfer of information across long distances (telecommunication) is a technology that has been with us for a while, in one form or another. The ancient Greeks used multiple signal fire-based communication paradigms to send simple messages. Similarly, Native Americans, ancient Chinese, and modern militaries have all used smoke to convey basic information from a distance.

Today, most people use Wi-Fi or cellular data when they want to send a message to someone far away. Both of these mediums rely on a massive infrastructure of ISPs and cellular networks to get data from one place to another. When these systems don’t work, it can be nearly impossible to communicate with the outside world. It's in these types of situations that a relatively new technology called Meshtastic can be a lifesaver.

What is Meshtastic?

Meshtastic is an open-source software project that takes advantage of the LoRa (LOng RAnge) radio standard to send text-based messages between two devices at distances of over 100 miles given ideal conditions (the current record is 158 miles). To get started with Meshtastic, all you need is a $25 development board with a radio and an antenna - and a smartphone of course. Messages are able to be sent from the smartphone app which connects with the radio via Bluetooth. The radio then transmits the signal which can be received by other LoRa radios running Meshtastic. All without use of Wi-Fi or cellular networks.

If you know a little bit about radio signal, you know that it works best with direct line of sight. Meshtastic overcomes this by turning every radio running its firmware into a node in a larger meshnet of devices. So, if you’re sending a message to someone, but your signal can’t reach them directly, the Meshtastic network will use other radios in the network to rebroadcast your message up to seven times (while the default number of hops is three) which greatly expands your range of communication.

What can you do with Meshtastic?

Because Meshtastic allows you unregulated communication (no ham license required) outside the traditional network of cell towers and Wi-Fi routers, it’s particularly popular among the prepper community (this is especially true because Meshtastic makes it easy to set up encrypted communication channels). Due to its low power requirements and built in redundancy, Meshtastic is a good choice for natural disaster communication when power and phone lines have been damaged.

Meshtastic is also an ideal platform for keeping in touch with friends during large public events. Cell towers have a hard limit on the number of concurrent users they can accommodate. When that limit is reached, no more users can connect, resulting in dropped service. Because of this, many people use Meshtastic to keep in touch with friends when going to concerts or festivals. You can also set up your radio to broadcast your GPS coordinates with your messages, making it easy to find your friends in crowds.

But Meshtastic doesn’t have to be just a medium of interpersonal communication. You can also integrate Meshtastic with MQTT, a web-based IoT communications protocol, allowing you to communicate with other MQTT-enabled devices. So, if you’re tech-savvy and willing to do some work, you could set up your smart home to talk to you over Meshtastic.

How does Meshtastic work?

The Meshtastic software makes use of the LoRa radio protocol, and LoRa is similar to FM radio in that it relies on frequency modulation to carry its information. But unlike analog FM signals, which are modulated in direct proportion to the audio waves they convey, LoRa broadcasts digital signals in the form of “chirps.” In radio parlance, a chirp is a signal that rises or falls in frequency a set amount over a set amount of time.

The math is too rigorous to get into here, but the chirps are what give LoRa its impressive range. Depending on your Meshtastic settings, your radio can produce anywhere from 128 to 4096 different chirps (default is 2048). The LoRa standard incorporates some mathematical trickery to make parsing those chirps computationally easy (which leads to a lower power draw). It also means that legible signals can be received even when they are all but lost in the noise of background radio emissions (which leads to its impressive range).

What devices run Meshtastic?

There are a number of devices available that Meshtastic has written firmware for, each with its own strengths and weaknesses.

The Heltec WiFi LoRa 32 is one of the most popular radios due to its small size and low cost. At just $20, it’s an easy expense to justify if you’re curious about checking it out. Like every other device I mention here, the Heltec radio comes with Wi-Fi, Bluetooth, and a LoRa antenna. Two things it doesn’t have are a battery (which is only included with pre-built units) and a GNSS antenna (which most other devices have).

Of all the LoRa device makers, LilyGo has the most Meshtastic-compatible products available. Its cheapest model is the LoRa32, which costs less than $20. It also makes the T-Echo, one of the few pre-built devices on the market that comes with a battery and E Ink screen for around $55. LilyGo also makes the $45 T-Deck, which has a built-in keyboard, meaning you don’t even need to pair it with your smartphone to use it.

Finally, there’s RAK, which offers modular LoRa systems that let you add just the components you need. RAK is a popular choice for those who want to build a Meshtastic node, a device that only functions to forward messages from other devices. RAK also has a pre-built device available for $100.

There are other vendors out there, but none enjoy the popularity of these big three. B&Q Consulting makes the $109 Station G2 (shown below), which is popular as an outdoor repeater. Waveshare makes a LoRa module made to interface with the Raspberry Pi Pico for just $15. And if you're looking for something more unique, there are lots of interesting options on Etsy and Tindie to choose from.

If you do decide to jump into Meshtastic, make sure that you get a device tuned to the correct frequency. If you’re in the US, you’ll need a radio tuned to 915MHz. If you’re not in the US, your other options are either 433MHz or 868MHz. Meshtastic has a list that covers most major regions, but you might have to do some digging to find out which one will be right for you. It might also behoove you to take a look at one of the Meshtastic maps so you can see if there will be anyone close enough to talk to when you get your radio.