Guide · LoRa · Off-grid

Meshtastic: text with no signal

Take a cheap ESP32, bolt on a LoRa radio, flash Meshtastic, and you have a pocket messenger that works where phones don’t: kilometres of range, no cell towers, no SIM, no monthly bill. Nodes relay for each other into a self-healing mesh — perfect for hiking, events and emergencies. Here’s how it reaches so far and how to build one.

MeshtasticLoRaESP32Off-gridMesh

A Meshtastic LoRa mesh: a phone paired over BLE to nodes that relay messages across kilometres, no towers — Your phone pairs to a node over Bluetooth; the nodes carry messages for each other across the mesh.

How LoRa reaches kilometres

LoRa trades speed for reach. Instead of pushing lots of data, it sends tiny messages very slowly using a chirp modulation that a receiver can dig out from below the noise floor — so a half-watt radio covers 5–15 km in the open (much less in a city). That’s useless for video and perfect for a text or a GPS ping. It’s the same physics behind LoRaWAN sensors; see where it sits versus Wi-Fi and BLE in the protocols guide.

Meshtastic — a mesh with no towers

Meshtastic is open-source firmware that turns those LoRa radios into a mesh chat network. Every node rebroadcasts messages it hears, so range compounds: two people out of direct reach still talk if a third node sits between them. There’s no base station and no account — the devices are the network. You get text, shared GPS positions on a map, and channels, all encrypted, all off-grid.

The boards to buy

The easiest path is a board with the LoRa radio (and often GPS) already on it:

Board	Has	Good for
LilyGO T-Beam	ESP32 + LoRa + GPS + 18650	the classic tracker node
Heltec LoRa 32	ESP32 + LoRa + small OLED	a cheap fixed/relay node
T-Deck / T-Echo	+ keyboard / e-paper	a standalone handheld
Any ESP32 + SX1276 module	DIY over SPI	rolling your own

Match the radio to your region’s LoRa band (868 MHz in the EU, 915 MHz in the US) — the wrong band is both illegal and won’t talk to local meshes.

Build a node in minutes

You barely write code: flash the ready-made Meshtastic firmware from the web flasher (browser, one click), then pair the device to the phone app over Bluetooth and set your region and channel. That’s a working node — send a message and watch it hop. For a range test, hand a second node to a friend and walk apart until packets stop.

Rolling your own over SPI

If you’re wiring a bare ESP32 to an SX127x / RFM95 LoRa module yourself, it talks SPI — the same handful of lines as any SPI peripheral, plus the DIO0 interrupt:

Wiring a LoRa SX1278 module to an ESP32 over SPI — SCK, MISO, MOSI, NSS, DIO0 and power — ESP32 ↔ LoRa SX1278 over SPI. Built in BoardLab — LoRa is never on the chip, always a module.

Wiring a different module? Draw any ESP + part in the browser, export the diagram.

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