signalk-meshcore

A SignalK Node Server plugin that integrates MeshCore LoRa mesh radio devices as AIS-style vessel targets — so crew nodes, tenders, and shore stations appear on your chart plotter / freeboard-sk with position, tracks, and battery data, exactly like AIS targets.

Connects to a MeshCore companion radio over TCP/WiFi or USB serial, using the official @liamcottle/meshcore.js library.

Development of this plugin was aided by AI-assisted coding tools.

See also: @meri-imperiumi/signalk-meshtastic — the equivalent plugin for Meshtastic LoRa devices. This plugin follows the same design principles and SignalK data model, making MeshCore and Meshtastic targets interoperable on the same chart.

Features

• TCP/WiFi and USB serial connection support, switchable in settings
• #TEL: telemetry decoding — 11-byte base64 payload → lat/lon, battery voltage, phone battery %, forward status
• Full AIS-compatible vessel metadata for each node — name, mmsi, design.aisShipType, communication.callsignVhf, navigation.position — so freeboard-sk renders them with the correct icon and popup details
• Channel filtering — listen on all channels or a chosen set. Channel 0 ("public") is hard-blocked for sending, always
• Persistent node database — last-known name/position/battery/timestamp survives SignalK restarts
• Vessel type selection — choose the AIS type code (and therefore freeboard-sk icon) for all MeshCore nodes (default: 37 Pleasure Craft)
• Share own position — periodically pushes this vessel's SignalK GNSS position to the MeshCore device's advertised location, so crew ashore can see the boat
• Broadcast own #TEL: telemetry — encodes this vessel's position/battery as a #TEL: message and sends it on a configured channel, so other MeshCore boats running this plugin (or any #TEL:-aware node) can see it
• Relay SignalK alerts to the mesh — sends a text message on a configured channel when a notification hits your chosen severity threshold (alarm, emergency, etc.)
• Associate nodes with existing AIS vessels — DE <callsign> name convention merges a node's data onto a matching vessel already in SignalK
• Auto-reconnect on connection drop, configurable delay
• Diagnostic frame logging — every incoming frame decoded as readable text in debug output

Requirements

• SignalK Node Server
• A MeshCore device running Companion Radio firmware (WiFi/TCP or USB serial variant)
• For MeshCore TEAM autonomous tracking, a companion radio running custom MeshCore firmware with GPS support. See the MeshCore TEAM GitHub repository and MeshCore firmware repository.
• Node.js 18+

Install

Via SignalK App Store (recommended)

1. Open your SignalK server admin UI.
2. Go to App Store → search for MeshCore Telemetry.
3. Install and restart.

Manual install

cd ~/.signalk
npm install signalk-meshcore --save
# then restart SignalK
sudo systemctl restart signalk

Configuration

Go to Server → Plugin Config → MeshCore Telemetry after installing.

Connection

| Setting | Description | Default | |---|---|---| | Connection type | TCP/WiFi or USB Serial | TCP/WiFi | | IP address | IP of the MeshCore device (TCP only) | 192.168.1.50 | | Port | TCP port (TCP only) | 5000 | | Serial port path | e.g. /dev/ttyUSB0, /dev/ttyACM0 (USB only) | /dev/ttyUSB0 | | Reconnect delay | Seconds before retrying after a drop | 10 |

USB serial note: on Linux you may need to add the SignalK user to the dialout group: sudo usermod -a -G dialout signalk

Receiving telemetry

| Setting | Description | Default | |---|---|---| | Listen on all channels | Receive #TEL: from every channel | On | | Channel indexes | Comma-separated list of channels to listen on, e.g. 1,2 (when all-channels is off) | 0 | | Vessel type | AIS ship type for MeshCore nodes. Controls the freeboard-sk icon. 37 = Pleasure Craft, 36 = Sailing Vessel, 51 = SAR, 52 = Tug, 90 = Other | 37 | | Persistent node database | Save last-known data for all nodes to disk | On |

Sending telemetry

| Setting | Description | Default | |---|---|---| | Share own position with mesh | Push this vessel's GNSS position to the MeshCore device's advertised location | Off | | Broadcast own #TEL: to mesh | Encode this vessel's position/battery as a #TEL: message and transmit it on the telemetry channel | Off | | Telemetry channel index | Channel to broadcast own #TEL: on. Never channel 0. | 1 | | Position share interval | How often to update (minutes) | 15 |

Alerts

| Setting | Description | Default | |---|---|---| | Relay SignalK alerts to mesh | Send text messages on MeshCore when notifications fire | Off | | Alert channel index | Channel to send alert messages on. Never channel 0. | 1 | | Minimum severity | alert / warn / alarm / emergency | alarm |

Advanced

| Setting | Description | Default | |---|---|---| | Associate nodes with AIS vessels | Match DE <callsign> node names to existing SignalK vessels | Off | | Capture location adverts from non-Team nodes | Opt-in. Also listen for MeshCore node advertisements and capture location when lat/lon are present. Repeater adverts are ignored. | Off |

How it works

Each MeshCore node that sends a #TEL: message gets its own SignalK vessel context:

vessels.urn:mrn:signalk:uuid:meshcore-<pubkey-prefix-hex>

The plugin publishes these SignalK paths for each node:

| Path | Value | |---|---| | navigation.position | lat/lon from TEL payload | | name | Node's advertised name | | communication.callsignVhf | Node's advertised name (doubles as callsign in freeboard-sk popup) | | mmsi | Synthetic 9-digit id (prefix 99) — not a real MMSI | | design.aisShipType | { id, name } — drives freeboard-sk icon | | electrical.batteries.meshcore.voltage | Battery voltage in volts | | sensors.meshcore.phoneBattery | Phone/companion app battery % | | sensors.meshcore.forwardStatus | Forward status byte from TEL payload |

SignalK stores position history per vessel context automatically, so tracks appear in freeboard-sk with no extra configuration — the same way real AIS targets do.

MeshCore TEAM autonomous mode

MeshCore TEAM's autonomous mode moves location tracking onto the companion radio itself. With custom firmware and a valid GPS fix, the radio keeps broadcasting telemetry even if the phone app is disconnected or out of range. The MeshCore TEAM app is available at tmacinc/MeshCore-TEAM.

For this plugin, that means the radio's #TEL: messages are the source of truth: it listens for those packets on the mesh, decodes the location/battery fields, and publishes them into SignalK as vessel targets with tracks.

#TEL: payload format

The 11-byte binary payload, base64-encoded after #TEL::

| Bytes | Field | |---|---| | 0–3 | Latitude as Int32BE × 10,000,000 | | 4–7 | Longitude as Int32BE × 10,000,000 | | 8 | Battery encoding: mV = ((byte − 2) × 6) + 2750 | | 9 | Phone/app battery % | | 10 | Forward status |

Relation to signalk-meshtastic

@meri-imperiumi/signalk-meshtastic provides the same SignalK integration for Meshtastic devices. This plugin follows the same data model and design principles, so MeshCore and Meshtastic nodes can coexist on the same SignalK server and appear together on freeboard-sk without conflict. Features like vessel association (DE <callsign>), persistent node database, own-position sharing, and alert relay are directly inspired by signalk-meshtastic.

License

GPL-3.0 — see LICENSE (GNU General Public License v3)