signalk-sailsense

signalk-sailsense

A Signal K plugin that connects to a SailSense Hub over MQTT and publishes all sensor data as raw Signal K values.

What it does

The SailSense Hub exposes boat data — batteries, tanks, breakers, actions, GPS, wind, depth, and power rail telemetry — over a local MQTT broker. This plugin subscribes to all of those topics and forwards every value into Signal K under a sailsense.* path namespace, making the data available to any Signal K instrument, logger, or automation.

Installation

Install from the Signal K AppStore inside the Signal K server UI, or via npm:

npm install signalk-sailsense

Then restart your Signal K server and enable the plugin under Server → Plugin Config → SailSense Hub.

Configuration

Field	Default	Description
MQTT Broker Host	192.168.50.231	IP address or hostname of the SailSense Hub on your local network
MQTT Broker Port	1883	MQTT port (standard; change only if you've customised the Hub)

Topic groups

Each topic group can be toggled independently in the plugin config UI to reduce noise:

Group	Default	Covers
Batteries	enabled	Voltage, current, charge level, alerts
Tanks	enabled	Fuel, fresh water, blackwater levels and alerts
Actions	enabled	Lights, pumps, and switch states
Breakers	enabled	Circuit breaker on/off states
Hub	enabled	GPS, wind, depth, IMU, Wi-Fi, Zigbee
Powernet	enabled	Power rail voltmeters, analog inputs, output states
UI Config	disabled	Hub interface configuration blobs (high-volume, low-value)

Signal K paths

MQTT topics are mapped to Signal K paths by:

1. Stripping structural children segments
2. Replacing / with .
3. Prefixing with sailsense.

Some examples:

MQTT topic	Signal K path
batteries/children/Main/children/Bank1/voltage	sailsense.batteries.Main.Bank1.voltage
tanks/children/water_tanks/children/water_tank_portside/levels/pct	sailsense.tanks.water_tanks.water_tank_portside.levels.pct
Hub/telematic/signalprocessed/rx	sailsense.Hub.telematic.signalprocessed.rx
breakers/children/HIFI/state	sailsense.breakers.HIFI.state
powernet/device/powerail/1/voltmeters/1/value	sailsense.powernet.device.powerail.1.voltmeters.1.value

Note on breaker paths: the hub also publishes a deeper path breakers/children/HIFI/children/HIFI/state, but that is a retained MQTT message that does not update with live state. Always read from sailsense.breakers.{Name}.state.

String payloads are coerced to native types: "True"/"False" become booleans, numeric strings become numbers, and JSON blobs are parsed into objects.

Subscribed topics

• batteries/# — battery voltage, current, percentage, remaining capacity, alerts
• tanks/# — tank levels (%, L, US gal) and alerts
• actions/# — switch/light states and dimmer steps
• breakers/# — breaker on/off states
• Hub/# — GPS, wind, depth, IMU, Wi-Fi, Zigbee, and telematic data
• powernet/# — power rail voltmeters, analog inputs, and output states
• ui_config/# — Hub UI configuration blobs

Dashboard

This package includes a built-in web dashboard, served by Signal K at:

http://<signalk-host>/signalk-sailsense/

The dashboard has four tabs:

Tab	Shows
Power	Battery bank voltage, current, and state of charge (dynamically discovered)
Tanks	PORT/STBD fill gauges for fresh water, fuel, and blackwater with litre readouts
Breakers	All 15 circuit breakers with live on/off indicators
Lights & Pumps	Nacelle, exterior, and cabin light states; bilge and water pump states

Data updates in real time via WebSocket with a 3-second REST polling fallback. No installation or build step required — it is a single HTML file bundled with the plugin.

Tabs can be deep-linked via URL hash: #power, #tanks, #breakers, #lights.

Browser compatibility

The dashboard is compatible with Chrome 70+, including the embedded Chromium browser on B&G Zeus 3 and similar Navico MFDs. No polyfills are required — the code avoids all JS and CSS features introduced after Chrome 70.

Authentication on MFDs

MFDs have no Signal K session cookie, so if Signal K has authentication enabled and Allow Read-Only Access is disabled, the dashboard will display an error rather than silently showing empty panels.

Two ways to fix this:

• Simplest: in Signal K admin go to Security and enable Allow Read-Only Access. This allows unauthenticated reads on a private boat LAN.
• Token-based: configure a JWT token in the signalk-navico-embedder plugin. The embedder injects the token into every proxied request and into the page as window.SK_TOKEN, which the dashboard picks up automatically.

Hardware reference

See DEVICES.md for a full map of breakers, lights, pumps, tanks, and Powerail outputs specific to the SailSense system.

License

MIT

Luke's development cheatsheet

npm link /Users/lukeescude/Code/signalk-navico-embedder && npm link /Users/lukeescude/Code/signalk-sailsense && signalk-server