signalk-brineomatic-plugin

SignalK plugin for interfacing with Brineomatic watermaker controllers. Now with reverse proxy for remote access via Tailscale or other VPN.

Setup

Add your board hosts and configure login info in the plugin preferences. Per-board options:

| Option | Default | Description | | ----------------- | ------------------ | ------------------------------------------ | | host | brineomatic.local| Hostname or IP of the Brineomatic board | | use_ssl | false | Connect via HTTPS / WSS | | update_interval | 1000 | Update poll interval in milliseconds | | require_login | false | Whether the board requires authentication | | username | admin | Username (if login required) | | password | admin | Password (if login required) | | enable_n2k | false | Publish watermaker status to the NMEA 2000 bus as PGN 130567 (see below) | | enable_proxy | false | Serve this board's web UI on a local port for remote access (see below) | | proxy_port | 3200 | Local port for this board's proxy (unique per board) | | water_temperature_path | (blank) | SignalK path to forward as source water temperature (see below) | | motor_temperature_path | (blank) | SignalK path to forward as pump motor temperature | | tank_level_path | (blank) | SignalK path to forward as fresh water tank level | | battery_level_path | (blank) | SignalK path to forward as battery state of charge |

Sending sensor data to the board

If your boat already measures water temperature, tank level, etc. elsewhere on the SignalK network, the plugin can forward those readings to the Brineomatic so it can use them instead of (or in addition to) its own sensors. Set any of the four *_path options to a SignalK path and the plugin subscribes to it and pushes each value to the board; leave an option blank to disable it.

| Option | Example path | Units sent to board | | ------------------------ | ----------------------------------------------- | ------------------- | | water_temperature_path | environment.water.temperature | °C (converted from SignalK's Kelvin) | | motor_temperature_path | propulsion.main.temperature | °C (converted from SignalK's Kelvin) | | tank_level_path | tanks.freshWater.0.currentLevel | ratio 0.0–1.0 | | battery_level_path | electrical.batteries.0.capacity.stateOfCharge | ratio 0.0–1.0 |

Updates are rate-limited to the board's update_interval and paused while the board is disconnected.

Publishing to NMEA 2000

With Enable Publishing to N2K ticked, the plugin broadcasts the board's state on the NMEA 2000 bus as PGN 130567 (Watermaker Input Setting and Status) every time an update arrives from the board (i.e. at the board's update_interval). This requires a SignalK NMEA 2000 connection with output enabled (e.g. a canbus/Actisense/YDGW connection with "Output Events" on).

Field mapping:

| PGN 130567 field | Brineomatic source | | -------------------------- | ----------------------------------------- | | Watermaker Operating State | status (RUNNING→Running, FLUSHING→Flushing, IDLE/PICKLED→Stopped, PICKLING/DEPICKLING→Rinsing, STARTUP→Initiating, …) | | Production Start/Stop | status == RUNNING | | Rinse Start/Stop, Flush Mode Status | status == FLUSHING | | Low Pressure Pump Status | boost_pump_on | | High Pressure Pump Status | high_pressure_pump_on | | Product Solenoid Valve Status | diverter_valve_open (open → Warning) | | Filter Status | Warning on run_result ERR_FILTER_PRESSURE_* | | Sensor Status | Warning on run_result ERR_MEMBRANE_PRESSURE_* (the PGN has no dedicated high-pressure warning field) | | Salinity Status | Warning on run_result ERR_PRODUCT_SALINITY_* | | System Status | Warning on any run_result ERR_* | | Oil Change Indicator Status | always OK | | Salinity | product_salinity (ppm) | | Product Water Temperature | water_temperature (source water — the PGN's only temperature field) | | Post-filter Pressure | filter_pressure | | System High Pressure | membrane_pressure | | Pre-filter Pressure, Feed Pressure | 0 (not measured by the board) | | Product Water Flow | product_flowrate (L/h) | | Brine Water Flow | brine_flowrate (L/h) | | Run Time | runtime_elapsed (current cycle; 0 when not reported) |

The warning indicators report OK until a run result says otherwise; fields the board has not yet reported (emergency stop, unseen sensor values) are transmitted as "unavailable". If you run several boards, note that PGN 130567 has no instance field — enable N2K publishing on only one board to avoid conflicting data.

Remote access (reverse proxy)

The Brineomatic board is an ESP32 on the boat LAN and can't run Tailscale itself, so its web UI isn't reachable when you're away from the boat. This plugin can stand up a transparent HTTP + WebSocket reverse proxy to each board so you can reach the board's own UI remotely — e.g. over Tailscale to the SignalK host.

Setup

1. In the plugin config, tick Enable remote-access proxy? for each board you want to reach, and give each one a unique Proxy port (e.g. 3200, 3201, …). Keep the port stable — it's part of the URL you'll bookmark.
2. Open the Brineomatic entry in the SignalK webapp list. With one board enabled it redirects straight to that board's UI; with several it shows a picker with each board's name and connection status.
3. Remotely, browse to the SignalK host over your VPN/Tailscale hostname; the proxy reuses whatever host you reached the page on and only swaps the port, so the same link works over Tailscale, LAN, or mDNS. Each board's UI is at http://<sk-host>:<proxy_port>/.

Security notes

• The proxy is opt-in — no port opens until you enable it for a board.
• The proxy port binds to all interfaces, so it's reachable over your VPN and the boat LAN, and it bypasses SignalK's own authentication. The board's own require_login (if enabled) still applies through the proxy. Treat your tailnet / LAN as the trust boundary and only enable the proxy on networks you trust.

SignalK Path Info

{boardname} is your board hostname, defaults to brineomatic

| Path | Units | Description | | -------------------------------------------------------- | ----- | ------------------------ | | watermaker.{boardname}.board.firmware_version | | Firmware version | | watermaker.{boardname}.board.hardware_version | | Hardware version | | watermaker.{boardname}.board.hostname | | Local board hostname | | watermaker.{boardname}.board.name | | User friendly name | | watermaker.{boardname}.board.uptime | s | Controller uptime | | watermaker.{boardname}.board.use_ssl | | Does the board use SSL? | | watermaker.{boardname}.board.uuid | | Unique ID of the board | | watermaker.{boardname}.board.bus_voltage | V | Supply voltage to the board (if reported) |

The rest of the data is located at watermaker.{boardname}.*:

| Path | Units | Description | | --------------------------------------------------------- | ------ | ------------------------------------------------ | | watermaker.{boardname}.status | | Current status of watermaker | | watermaker.{boardname}.run_result | | Result from last run cycle | | watermaker.{boardname}.flush_result | | Result from last flush cycle | | watermaker.{boardname}.pickle_result | | Result from last pickle cycle | | watermaker.{boardname}.depickle_result | | Result from last depickle cycle | | watermaker.{boardname}.motor_temperature | K | Motor temperature | | watermaker.{boardname}.water_temperature | K | Source water temperature | | watermaker.{boardname}.flowrate | m³/s | Product output flowrate (legacy alias of product_flowrate) | | watermaker.{boardname}.product_flowrate | m³/s | Product output flowrate | | watermaker.{boardname}.brine_flowrate | m³/s | Brine output flowrate | | watermaker.{boardname}.total_flowrate | m³/s | Total output flowrate | | watermaker.{boardname}.volume | m³ | Product output volume total (this cycle) | | watermaker.{boardname}.flush_volume | m³ | Flush volume total (this cycle) | | watermaker.{boardname}.salinity | PPM | Product output salinity (legacy alias of product_salinity) | | watermaker.{boardname}.product_salinity | PPM | Product output salinity | | watermaker.{boardname}.brine_salinity | PPM | Brine output salinity | | watermaker.{boardname}.filter_pressure | Pa | Pre-filter Pressure | | watermaker.{boardname}.membrane_pressure | Pa | Membrane Pressure | | watermaker.{boardname}.tank_level | ratio | Tank level percentage | | watermaker.{boardname}.boost_pump_on | | Status of the boost pump | | watermaker.{boardname}.high_pressure_pump_on | | Status of the high pressure pump | | watermaker.{boardname}.diverter_valve_open | | Status of the diverter valve | | watermaker.{boardname}.flush_valve_open | | Status of the flush valve | | watermaker.{boardname}.cooling_fan_on | | Status of the cooling fan | | watermaker.{boardname}.next_flush_countdown | s | Time until next automatic flush cycle | | watermaker.{boardname}.runtime_elapsed | s | Total elapsed time for watermaking cycle | | watermaker.{boardname}.finish_countdown | s | Time until watermaker cycle completes (estimate) | | watermaker.{boardname}.flush_elapsed | s | Time elapsed for flush cycle | | watermaker.{boardname}.flush_countdown | s | Time until flush cycle completes | | watermaker.{boardname}.pickle_elapsed | s | Time elapsed for pickle cycle | | watermaker.{boardname}.pickle_countdown | s | Time until pickle cycle completes | | watermaker.{boardname}.depickle_elapsed | s | Time elapsed for depickle cycle | | watermaker.{boardname}.depickle_countdown | s | Time until depickle cycle completes |

Development

Install dependencies and run the checks:

npm install
npm test          # run the test suite
npm run test:coverage   # run tests with a coverage report
npm run lint      # eslint

The tests use Node's built-in test runner (node:test, Node 18+) — no extra test dependencies are needed. They cover:

• signalk-bus.js — delta/meta queuing, batching, de-duplication.
• index.js — the plugin schema, the /boards route, the yarrboard-client message routing, and the unit conversions applied to each update (°C→K, mL/h→m³/s, bar→Pa, ms→s, …). No board connection is opened.
• n2k-publisher.js — the PGN 130567 field mapping, status enum translation, unit conversions, and partial-update caching. Nothing is put on a real bus; the emitted canboat-JSON is asserted directly.
• board-proxy.js — descriptor filtering (enable/port/duplicate), target URL building, and the /boards metadata. ReverseProxy is stubbed so no ports are opened.
• reverse-proxy.js — real HTTP and WebSocket proxying over loopback sockets, header stripping, 502 on an unreachable upstream, and EADDRINUSE handling.

Icons

The favicons, the iOS/Android home-screen icons, and the SignalK app store icon (signalk.appIcon) are all generated from the single square source assets/icon.png into public/icons/:

npm run icons

The outputs are committed to git — re-run this only when the source icon changes. assets/ is dev-only and is not published to npm.