Do I need a node or a gateway?

No. Two communicators in range talk to each other directly over radio. Sensmos nodes and gateways that hear a message carry it on, over the internet, to people out of radio range.

Is delivery guaranteed?

No — it is radio. A message over radio is heard if a communicator, node or gateway is in range; there is no mesh and no multi-hop. Over the internet, the server keeps messages for you for 48 hours.

Is the communicator a node?

No. A node measures the internet, holds the tunnel to your LAN and earns GALU. The communicator only sends and receives messages. They run different firmware — each has its own flasher page.

The app creates one for you at start; your communicator ID is derived from it. You do not need a node.

Sensmos Communicator — text messages over LoRa radio when the internet is down

How it works

Your phone is the screen and keyboard; the communicator is the radio. They connect over Bluetooth with one tap — no pairing dialog, no PIN. You can set a PIN in the Device tab if you want one; your phone remembers it.
With internet, a message goes over the internet. Without it, it goes over radio: straight to communicators in range, and on through Sensmos nodes and gateways that hear it.
Every message shows which way it came: 📶 internet or 📻 radio.
When your phone is not around, the communicator collects messages addressed to you and hands them over once you connect.

Chats and groups

Add a contact by their ID, or from the “Nearby” list — people your communicator has heard over radio. A tap opens the chat.
A group is a shared key: whoever has it writes and reads. You hand the key out yourself; the server only gets its fingerprint.
Your name (up to 10 characters) travels with your messages over radio, so others know who is writing — even with no internet at all.

Privacy

Your phone encrypts the content. The server relays encrypted messages and does not know group keys, group names or what is said.
You choose your visibility: hidden, “nearby”, or a dot on the map next to the gateway that hears you (no GPS).

Screen

A Heltec Wireless Paper shows on its e-paper: your name and ID, the radio state, the latest message (“sender: text”), and at the bottom how many communicators are nearby, the last radio reception and airtime used. Choose the panel in the app (Communicator → Device → Display); the display is optional — a board without one works the same.
With your phone connected the app hands the communicator a copy of your keys (identity, groups, contact names), encrypted to the device's own key. From then on it reads messages by itself, shows them on the screen and — when your phone is not around — acknowledges delivery. “Disconnect communicator” wipes the keys. The keys live in the device's memory: whoever holds the board, holds the keys.

Boards

Any ESP32-S3 board with an SX1262 radio the firmware knows: Heltec WiFi LoRa 32 V3, Heltec Wireless Paper, Seeed XIAO ESP32-S3 + Wio-SX1262, LilyGo T3-S3, LilyGo T-Beam S3 Core, RAK3312. One file — the firmware detects the board. No display needed; the phone is the screen.
Europe (868 MHz) for now.
The firmware is open source: src/kom in the Sensmos firmware repository — the same tree as the node firmware, built with SENSMOS_KOM=1.

Getting started

Flash the communicator from your browser.
Install the Sensmos app and choose “I want to use it without a node (wallet only)”.
In the app: Communicator → Device → pick your communicator from the list.

Messages that get through without the internet.