A single-binary web application for monitoring and analyzing LoRa (Long Range) wireless traffic. The backend is Go (gin); the frontend is React with MUI, built with bun and embedded in the binary. It needs no internet access to run.

Features

Live frames: a Wireshark-style list of everything received (raw serial lines, decoded LoRa packets, LoRaWAN gateway traffic) with filtering, pause/follow and CSV export.
Devices: a live table of every device heard, with frequency, signal strength, first/last seen and frame count.
Any number of transceivers: add as many Feathers as you like; each one's frequency (433, 868, 915 MHz, ...) is detected automatically from the firmware's boot banner. View any device's raw serial output.
Transmit: one-off messages and server-side beacons that keep running when the page is closed.
LoRaWAN gateways: add any number of Dragino LPS8N gateways; their traffic logs are polled on a configurable interval.
Hardware: an Adafruit Feather M0 or 32u4 running the Skinny LoRa firmware (steps 1-2 in its README). For 433 MHz you need the Adafruit Feather M0 LoRa 433 MHz.

Build and run

Requires Go 1.24+ and bun.

make build          # bun builds web/dist, then go build -> ./lora-scanner
./lora-scanner      # http://localhost:5000

The result is one self-contained binary. The frontend uses no CDNs or web fonts, and make build fails if it ever references anything that isn't embedded. Every route under /api is the JSON/WebSocket API; any other URL serves the web interface.

Options:

Option	Default	Purpose
`--addr` / `LORA_ADDR`	`:5000`	listen address
`--config` / `LORA_CONFIG`	`gateways.json` in the per-user config directory	gateway list and poll interval
`LORA_GATEWAY_USER` / `LORA_GATEWAY_PASS`	`root` / `dragino`	gateway web login

The config directory is ~/.config/lora-scanner/ on Linux, ~/Library/Application Support/lora-scanner/ on macOS and %AppData%\lora-scanner\ on Windows, so the binary can live anywhere, including a read-only bin. On first run, an old gateway_config.json in the working directory is imported if present (and never modified).

Development: make dev runs the API; in another shell cd web && bun run dev (the Bun dev server on :5173 proxies /api to port 5000). Tests: make test.

Usage

The screenshots below were taken against simulated Feathers and a stand-in gateway.

Configuration

Click Add Transceiver and pick the serial port of a Feather. Its frequency shows up once the firmware reports it (the Feather prints it once at boot, so replug a board that shows "Detecting…"). Add as many as you like, including several on the same band.

View Serial shows everything a device prints, read-only:

Add Dragino gateways by IP, with no limit. A gateway turns red after two failed polls in a row and is retried every 5 seconds until it answers; green means its last poll worked, and grey means it hasn't been polled yet. The poll interval (5-3600 seconds, default 30) is set here too.

Frames

Every frame as it arrives: raw serial lines, decoded LoRa packets and LoRaWAN gateway rows (the last 10,000 are kept). Filter by text or kind (LoRa, LoRaWAN, Raw), select a row for its details, pause the view, or download everything as CSV. Follow keeps the newest frame in view and switches itself off when you scroll up.

Devices

A live table of every device heard: identifier, frequency, signal strength, first and last seen, and how many frames it has sent. Select a device to jump to its frames.

Transmit

The only place anything is transmitted. Send a message from a chosen transceiver, or start a beacon that repeats it every N milliseconds (minimum 1000) to probe nearby devices. Beacons run on the server and keep going if you close the page.

API

Endpoint	Purpose
`GET /api/ports`	serial ports on this machine
`GET/POST /api/transceivers` `{port}`	list / add a Feather; its frequency is detected from the firmware's `Freq set to:` boot line
`DELETE /api/transceivers/{id}`	remove
`POST /api/transceivers/{id}/transmit` `{text}`	send `TX:<text>`
`GET/POST/DELETE /api/transceivers/{id}/beacon`	server-side periodic transmit (`{text, intervalMs>=1000}`)
`GET/PUT /api/gateways/poll` `{seconds}`	how often gateways are polled
`GET/POST /api/gateways` `{ip}`, `DELETE /api/gateways/{ip}`, `GET /api/gateways/status`	gateway list and each gateway's state from its last poll (`online`/`offline`/`unknown`, with the error)
`GET /api/frames?after=<id>`, `DELETE /api/frames`, `GET /api/frames.csv`	received frames (last 10,000 kept)
`GET /api/devices`	devices aggregated from frames
`GET /api/ws`	WebSocket: live `transceivers`, `gateways` (state changes), `frame` and `device` messages

License

MIT, see LICENSE.