swaitsandClaude Opus 4.7
f83d4088e3
Every "Test vectors: \`corpus/...\`" mention in the spec is now a markdown link pointing at the corresponding file or directory on GitHub. Each version build resolves its links to the correct git ref: - /latest/ -> https://github.com/swaits/meshcore-spec/tree/main/corpus/... - /v0.1.0/ -> https://github.com/swaits/meshcore-spec/tree/v0.1.0/corpus/... - future /vX.Y.Z/ -> /tree/vX.Y.Z/corpus/... Two changes: 1. src/*.md (18 files): the inline-code corpus paths in each "Cross-References" section are now markdown links. Directories point at /tree/main/corpus/..., individual .json files point at /blob/main/corpus/.... CHANGELOG and other non-corpus main links are intentionally left pointing at main — the canonical history lives there regardless of which version you're reading. 2. justfile: `cut-version` now also runs a sed over the snapshot's *.md files replacing /tree/main/corpus -> /tree/<VERSION>/corpus and /blob/main/corpus -> /blob/<VERSION>/corpus. So a freshly-cut version is self-consistent. versions/v0.1.0/* regenerated by re-running `just cut-version v0.1.0` after the new src/ links + recipe sed landed. Tagging the release commit (`git tag v0.1.0`) is now REQUIRED — not "optional" — because the rendered /v0.1.0/ pages reference /tree/v0.1.0/corpus/... on GitHub. Without the tag the links 404. cut-version's output now says so. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
97 lines
3.2 KiB
Markdown
97 lines
3.2 KiB
Markdown
# MeshCore Protocol Specification
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## Section 18: Companion Protocol
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### Overview
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The companion protocol enables BLE (Bluetooth Low Energy) and serial
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communication between a MeshCore radio and a companion app (phone, tablet, or
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computer). It uses a binary framing format over the Nordic UART Service (NUS)
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BLE profile.
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### BLE Service
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| UUID | Description |
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|------|-------------|
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| `6E400001-B5A3-F393-E0A9-E50E24DCCA9E` | Nordic UART Service |
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| `6E400002-...` | RX Characteristic (app writes to radio) |
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| `6E400003-...` | TX Characteristic (radio notifies app) |
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### Frame Format
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Each companion protocol frame consists of a 1-byte type identifier followed by
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variable-length data:
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```
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[type(1)][data(0-171)]
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```
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Maximum frame size is 172 bytes.
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### Message Types (Radio to App)
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| Type | Value | Description |
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|------|-------|-------------|
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| PACKET_CHANNEL_MSG_RECV | 0x01 | Channel message received |
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| PACKET_CONTACT_MSG_RECV | 0x02 | Contact message received |
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| PACKET_ADV_RECV | 0x03 | Advertisement received |
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| PACKET_CONTACT_MSG_RECV_V3 | 0x04 | Contact message V3 (includes SNR) |
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| PACKET_CHANNEL_MSG_RECV_V3 | 0x05 | Channel message V3 (includes SNR) |
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### Command Types (App to Radio)
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| Command | Value | Description |
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|---------|-------|-------------|
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| CMD_APP_START | 0x01 | Initialize connection |
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| CMD_DEVICE_QUERY | 0x02 | Query device info |
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| CMD_SET_CHANNEL | 0x03 | Set active channel |
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| CMD_SEND_CHANNEL_MESSAGE | 0x04 | Send message to channel |
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| CMD_SEND_CONTACT_MESSAGE | 0x05 | Send message to contact |
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| CMD_GET_CONTACTS | 0x06 | Get contact list |
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| CMD_GET_CHANNELS | 0x07 | Get channel list |
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| CMD_SET_TIME | 0x08 | Set device time |
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| CMD_ADD_CONTACT | 0x09 | Add a contact |
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| CMD_ADD_CHANNEL | 0x0A | Add a channel |
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| CMD_SEND_LOGIN | 0x0B | Login to room/repeater |
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| CMD_GET_SETTINGS | 0x0C | Get device settings |
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| CMD_SET_SETTINGS | 0x0D | Set device settings |
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| CMD_REMOVE_CONTACT | 0x0E | Remove a contact |
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| CMD_REMOVE_CHANNEL | 0x0F | Remove a channel |
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| CMD_SHARE_CONTACT | 0x10 | Share contact info |
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| CMD_SET_ADV_NAME | 0x11 | Set advertisement name |
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| CMD_REBOOT | 0x12 | Reboot device |
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| CMD_SEND_RAW | 0x13 | Send raw packet |
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### Connection Sequence
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1. Scan for BLE devices advertising the Nordic UART Service.
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2. Connect and discover services.
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3. Enable notifications on the TX characteristic.
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4. Send `CMD_APP_START` to initialize.
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5. Send `CMD_DEVICE_QUERY` to get device info.
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6. Send `CMD_SET_TIME` to synchronize clock.
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7. Send `CMD_GET_CONTACTS` and `CMD_GET_CHANNELS` to fetch state.
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### Byte Order
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All multi-byte integers in the companion protocol are **little-endian**, except
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for CayenneLPP sensor data which uses **big-endian**.
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### Message Length Limit
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Text messages are limited to 133 characters.
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### MTU Considerations
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The default BLE MTU is 23 bytes (20 bytes of payload). For complex operations,
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implementations SHOULD request a larger MTU (up to 512 bytes).
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### Cross-References
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- [Section 1: Wire Format](01-wire-format.md) — Underlying packet format
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- Test vectors: [`corpus/companion/`](https://github.com/swaits/meshcore-spec/tree/v0.1.0/corpus/companion/)
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### Reference Implementation
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- `docs/companion_protocol.md` in the MeshCore repository
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