LoRa Scanner: a MeshCore preset, and its packets read

- MeshCore joins the presets (EU/UK Narrow: 869.618 MHz, 62.5 kHz, SF8, CR 4/8, sync 0x12), after the Meshtastic ones so stored choices keep their number; `lora preset MeshCore` on the console - lib/meshcore reads what MeshCore sends in clear: header, path, and a node's advert (name, kind, key, position) - the list row, the details, a Capture's viewer and the console echo read a packet by the sync word it was received on - the bandwidth is printed as 62.5, not 62 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk
2026-10-09 20:30:29 +02:00
parent 861a60b73d
commit 8ba41f72b6
23 changed files with 622 additions and 62 deletions
@@ -21,7 +21,7 @@ boot other        restart into the other app slot (manual Rollback)
 log level <0-5>   ESP-IDF log level (0 none ... 5 verbose)
 ls [folder] | du <path> | mkdir <path> | rm [-r] [-f] <path> | cp [-f] <from> <to> | mv [-f] <from> <to> | cancel   the SD card, with the Storage App's rules (rm -r for a folder; -f: the Shell doesn't ask; * and ? in a name: /notes/*.txt)
 screenshot [seconds]   the screen as a PNG in /screenshots on the card, now or after a pause
-lora probe | lora status | lora rx on|off | lora preset <name>   the LoRa radio, receive only
+lora probe | lora status | lora rx on|off | lora preset <name>   the LoRa radio, receive only; a Meshtastic preset (LongFast...) or MeshCore
 lora capture start|stop   a LoRa Capture to /captures/lora (pcap, LoRaTap)
 lora sweep on [from MHz] [to MHz] [step kHz] | lora sweep off | lora sweep dump   RSSI across a band (863 870 100)
 lora custom <MHz> <BW kHz> <SF> <CR 5-8> <sync hex> [preamble]   e.g. 868.1 125 7 5 34 8 (LoRaWAN)
@@ -102,7 +102,7 @@ In **Safe Mode** (see [Crashes and Safe Mode](/dev/debug/crashes/)) only a few r
 | `lora probe` | Finds the radio: chip, oscillator, antenna switch, DIO1 interrupt, noise floor |
 | `lora status` | Radio settings, who's listening, packet and error counters, noise floor, task stack |
 | `lora rx on` / `lora rx off` | Listens and prints each packet on the console |
-| `lora preset <name>` / `lora custom <MHz> <BW kHz> <SF> <CR> <sync hex> [preamble]` | Receive settings: a Meshtastic preset, or anything else (`lora custom 868.1 125 7 5 34 8` for LoRaWAN) |
+| `lora preset <name>` / `lora custom <MHz> <BW kHz> <SF> <CR> <sync hex> [preamble]` | Receive settings: a Meshtastic preset or `MeshCore`, or anything else (`lora custom 868.1 125 7 5 34 8` for LoRaWAN) |
 | `lora capture start` / `lora capture stop` | A LoRa Capture, as `c` in the App |
 | `lora sweep on [from MHz] [to MHz] [step kHz]` / `lora sweep off` / `lora sweep dump` | Sweep a band (863 870 100 by default), with a summary every 2 s (floor, strongest, peaks), or print the latest pass |
 | `gnss quiet on` / `gnss quiet off` | The "Pause GNSS for LoRa" setting |
@@ -12,7 +12,7 @@ Press **<kbd>Fn</kbd> + <kbd>h</kbd>**, on any screen: it lists the keys that wo

 ## Can I send messages over the mesh?

-**Not yet.** The LoRa Scanner **listens** to Meshtastic traffic and shows what it hears, but nothing is transmitted. A mesh messenger is the goal and is planned in two milestones, one for receiving and one for transmitting; it waits for a second node to test against.
+**Not yet.** The LoRa Scanner **listens** to Meshtastic or MeshCore traffic and shows what it hears, but nothing is transmitted. A mesh messenger is the goal and is planned in two milestones, one for receiving and one for transmitting; it waits for a second node to test against.

 ## Is this Meshtastic?

@@ -13,14 +13,38 @@ The Scanner uses the **Cap LoRa-1262**. It **never transmits**: it listens and s

 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.

+For a **MeshCore** packet it shows what the packet is, who it concerns and how many repeaters are in its path:
+
+| Row | Is |
+|---|---|
+| `adv Brussels-R1 2h` | A node saying who it is, by its name, heard through 2 repeaters |
+| `txt a3>7f` | A private message from the node whose key starts with `a3` to the one starting with `7f` (`req`, `rsp` and `path` look the same) |
+| `chan #11 1h` | A message on a channel; `#11` is the channel's byte, and `11` is the public channel's |
+| `ack`, `anon`, `trace`, `ctl` | An acknowledgement, a login, a trace, a discovery |
+
 | 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>Enter</kbd> | The details of a packet: what is never encrypted (below), and a hex dump |
+| <kbd>p</kbd> | Picks what to listen to: one of the 7 Meshtastic presets allowed in EU868 (LongFast by default), or **MeshCore** |
 | <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.
+The Scanner shows the header and the bytes; it does not decrypt the message itself, which Meshtastic and MeshCore both encrypt.
+
+**One network at a time.** The radio listens on one frequency with one setting, and the two networks share neither: on a Meshtastic preset no MeshCore packet is heard, and the other way round.
+
+### MeshCore
+
+The **MeshCore** preset is the setting its networks use in Europe, "EU/UK (Narrow)": 869.618 MHz, 62.5 kHz wide, SF8, coding rate 4/8. A network set up differently needs `lora custom` in the [Shell](/guide/shell/).
+
+<kbd>Enter</kbd> on a MeshCore packet shows:
+
+- what it is and how it travels: **flood** (every repeater passes it on, and adds itself to the path) or **direct** (it carries the route to follow);
+- the path, one repeater a hop, each named by the first byte of its key;
+- for an **advert**, which is signed and never encrypted: the node's name, its kind (chat node, repeater, room server, sensor), the start of its key, and its position if it gives one;
+- for a message: the first byte of the sender's and the receiver's keys, or the channel's byte, and how many bytes are encrypted.
+
+A byte is all a packet says about who it is from: two nodes can share it. The name comes only with a node's advert, which a node sends now and then, so a quiet network can take a while to show its names.

 ## Capture

@@ -36,7 +36,7 @@ The App says why when it refuses.

 - **Text** (`.txt`, `.log`, `.gmi`, `.csv`, and anything that looks like text): only a screenful is read from the card, so a file of any size opens at once, and logs open at the end. Up and down move a line, left and right a page, <kbd>t</kbd> and <kbd>b</kbd> go to the top and the end, and <kbd>e</kbd> edits it, whatever its size (as in [Notes](/guide/notes/)).
 - **Pictures** (`.png`, `.jpg`, `.bmp`, `.gif`): see [Pictures](#pictures) below.
- **Captures** (`.pcap`): the packets as the [LoRa Scanner](/guide/lora-scanner/) lists them; <kbd>Enter</kbd> shows one with its Meshtastic header and bytes.
+- **Captures** (`.pcap`): the packets as the [LoRa Scanner](/guide/lora-scanner/) lists them; <kbd>Enter</kbd> shows one with its Meshtastic or MeshCore header and bytes.
 - **Tracks** (`.gpx`): the number of points, the start, the duration and the distance.
 - **Update files** (`.ota`): the version, and whether the file would install: it is checked as an install checks it, signature and contents, without writing anything. <kbd>Enter</kbd> then installs it (see [Updates](/guide/updates/)).
 - **Anything else:** a hex dump.
@@ -9,7 +9,7 @@ tag = "LoRa Scanner"
 The radio only **listens**: nothing is transmitted. You need the **Cap LoRa-1262** and an **SD card**.

 1. **Open the LoRa Scanner.** The Status Bar shows `L` while the radio listens.
-2. **Pick a preset with <kbd>p</kbd>.** The Scanner offers the 7 Meshtastic presets allowed in EU868; LongFast is the default.
+2. **Pick a preset with <kbd>p</kbd>.** The Scanner offers the 7 Meshtastic presets allowed in EU868 (LongFast is the default) and MeshCore.
 3. **Wait for packets.** Each line is a packet: the time, RSSI and SNR, and for a Meshtastic packet the sender, the receiver and the hops. <kbd>Enter</kbd> shows a packet's header and its bytes.
 4. **Press <kbd>c</kbd> to start a capture.** The Status Bar shows `CAP`. It keeps recording with the App closed.
 5. **Press <kbd>c</kbd> again to stop.**
@@ -5,7 +5,7 @@
 num = "01"
 tag = "LoRa Scanner"
 title = "See what is on the air"
-text = "Lists every packet it hears with time, RSSI, SNR, sender and hops, reading the Meshtastic header. A Sweep shows signal strength from 863 to 870 MHz. Capture to a pcap for Wireshark."
+text = "Lists every packet it hears with time, RSSI, SNR, sender and hops, reading the Meshtastic or MeshCore header. A Sweep shows signal strength from 863 to 870 MHz. Capture to a pcap for Wireshark."
 fact = "Only listens, never transmits"
 icon = 1

@@ -206,7 +206,7 @@ title = "LoRa Scanner, the packets"
 rows = [
    ["; .", "up, down"],
    ["Enter", "the packet's details"],
-    ["p", "pick a Meshtastic preset"],
+    ["p", "pick a preset"],
    ["c", "start a Capture, or stop it"],
    ["Tab", "the Sweep"],
 ]