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Gadget 02 · Your own network

Meshtastic: your own network

Meshtastic is an open-source project that turns small, low-power radios into a messaging network that depends on nothing: no towers, no internet, no satellites. Every device that joins extends the network.

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How it works

Each device is a radio, a technology designed to send small amounts of data over long distances using very little battery. You pair it with your phone over Bluetooth and type in an app that looks like any chat app.

  1. Your message goes out by radio from your device.
  2. Any other Meshtastic device that hears it rebroadcasts it. The message hops from node to node until it reaches its destination: that's what a mesh network is.
  3. By default, each message can make up to 3 hops. More hops isn't always better: they flood the network with echoes.
  4. Channels are encrypted, so only people with the channel key can read the message.
License
None needed
Fees
None
Messages
Text and GPS position
Battery
Days to weeks

Real-world range

It depends mostly on height and obstacles, more than on the device:

  • In a city, at street level: from a few hundred yards to a mile or so.
  • With a node on a rooftop or high balcony: several miles.
  • Between mountains with line of sight: dozens of miles. Much longer records exist, but they're exceptional.

The trick is having fixed nodes in high places. A small solar-powered radio on a roof can cover an entire neighborhood. Many cities already have hobbyist communities with working meshes: look for yours.

The right frequency

Important when buying

LoRa uses license-free bands that vary by region: 915 MHz in the Americas and 868 MHz in Europe. Buy the version for your region and set it in the app. Using the wrong one is illegal, and you won't connect with anyone.

What it's good for in an emergency

  • Staying in touch with family and neighbors when the cell network goes down, such as in a long outage.
  • Coordinating a town, a neighborhood or a group in the backcountry.
  • Sharing everyone's position on a map without data.

What it doesn't do: it doesn't connect you to emergency services. You can only talk to people with another Meshtastic device within reach of the mesh. That's why it works best as a group project: two devices at minimum, ideally three or four.

Which device to buy

To carry: SenseCAP T1000-E

Credit-card sized, water-resistant, with GPS and a battery that lasts several days. Ideal for each family member.

With its own screen: LILYGO T-Echo

An e-ink display, very readable in sunlight and extremely low-power. Lets you read messages without taking out your phone.

For a fixed rooftop node: RAK WisBlock

Modular and very low-power. With a weatherproof box and a small solar panel it becomes a permanent repeater.

To try it cheaply: Heltec V4

The official, inexpensive board for experimenting. Needs a case and battery bought separately: see the DIY version below.

Get started in an afternoon

  1. Buy two devices for your region's band.
  2. Install the official Meshtastic app on your phone and pair them via Bluetooth.
  3. Set the region in the settings: it's mandatory before transmitting.
  4. Create a private channel for your family and share the key with a QR code.
  5. Test the range: one at home and the other on a walk around the neighborhood.

DIY version: build it yourself

If you'd rather save money, you can build a Meshtastic node from a cheap board, an antenna and a battery for well under the price of a finished device. This isn't a tutorial: here are the official resources and the parts. It takes some patience and a steady hand.

Resources

  • Official firmware: github.com/meshtastic/firmware, open source.
  • Web flasher: flasher.meshtastic.org. Flashes the firmware from your browser over USB, nothing to install.
  • Supported boards: meshtastic.org, under devices.
  • 3D-printable cases: search "Meshtastic" on Printables or Thingiverse for your board.

Parts

  • A LoRa board such as the Heltec V4, set to your region's band (868 MHz in Europe, 915 MHz in the Americas).
  • A better antenna than the stock one: it adds more range than anything else.
  • A 3.7 V LiPo battery with your board's connector.
  • For a fixed repeater: a weatherproof box and a small 5 V solar panel.

Before you power it on

Never power a LoRa board without its antenna attached: it can damage the radio chip.

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