Public Access
twislaandClaude Opus 5.5
34e6714785
Every screen's keys are constant tables in lib/core/src/app_keys.h (52 of them, each under an `// id: Title` comment). An App's help() picks the table of the state it is in. site/tools/gen_dev_docs.py reads the same file and writes site/data/keys.toml; the `keys` shortcode shows a screen's tables on its guide page, and /guide/keys/ shows all of them. The Site job fails when the data file is out of date or a page asks for a table that doesn't exist, and now also runs when app_keys.h changes. A key added to an App shows up on the website without anyone editing a page. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
42 lines
2.3 KiB
Markdown
42 lines
2.3 KiB
Markdown
+++
|
|
title = "LoRa Scanner"
|
|
description = "Listen to the radio: every packet it hears, a survey of signal strength from 863 to 870 MHz, and captures for Wireshark. It only listens."
|
|
weight = 2
|
|
[extra]
|
|
tag = "LoRa Scanner"
|
|
screens = ["sniffer.png", "sweep.png"]
|
|
+++
|
|
|
|
The Scanner uses the **Cap LoRa-1262**. It **never transmits**: it listens and shows.
|
|
|
|
## Sniffer
|
|
|
|
The first view lists what the radio hears, newest first: the time, the RSSI (signal strength, in dBm) and the SNR (signal over noise, in dB). For a **Meshtastic** packet it also shows the sender and the receiver (the last four hex digits of their numbers) and the number of hops.
|
|
|
|
| Key | Does |
|
|
|---|---|
|
|
| <kbd>Enter</kbd> | The details of a packet: the Meshtastic header, which is never encrypted, and a hex dump |
|
|
| <kbd>p</kbd> | Picks one of the 7 Meshtastic presets allowed in EU868 (LongFast by default) |
|
|
| <kbd>c</kbd> | Starts or stops a **capture** |
|
|
| <kbd>Tab</kbd> | Switches to the Sweep |
|
|
|
|
The Scanner shows the header and the bytes; it does not decrypt the message itself, which Meshtastic encrypts with the channel's key.
|
|
|
|
## Capture
|
|
|
|
A capture records packets into a **pcap** file with LoRaTap headers in `/captures/lora/` on the SD card, to open in Wireshark. It keeps recording with the App closed (the Status Bar shows `CAP`); the radio sleeps when the App is not open and no capture is running. Captures are never deleted unless you ask, in the [Storage App](/guide/storage/), which can also show a pcap's packets on the device.
|
|
|
|
## Sweep
|
|
|
|
<kbd>Tab</kbd> switches to the Sweep: the signal strength across **863 to 870 MHz** in 100 kHz steps, drawn as bars with a mark at each peak, and a waterfall under them. The frequency the Sniffer listens on is marked. The Sniffer is paused during a Sweep and picks up where it was. The Status Bar shows `SW`.
|
|
|
|
## The GNSS receiver raises the noise
|
|
|
|
The GNSS receiver on the same Cap makes the radio's noise floor about **8 dB** worse while it runs. **Settings → Pause GNSS for LoRa** (off by default) puts the receiver on standby while the radio listens, except while a Track is being recorded.
|
|
|
|
## The keys, as the device lists them
|
|
|
|
What <kbd>Fn</kbd> + <kbd>h</kbd> shows on these screens. These tables are generated from the firmware's own lists, so they are always the current ones.
|
|
|
|
{{ keys(scopes=["lora", "lora-packet", "lora-presets", "lora-sweep"]) }}
|