SignalK SMS Notifications via Teltonika Routers

Relays SignalK notifications (e.g. an anchor watch alert) as SMS via a Teltonika cellular router's RutOS REST API - useful when the boat has no other way to reach you (no internet, generator/battery notifications while ashore, etc).

Messages can be prefixed with the alarm state, e.g. CRITICAL, and optionally broken up into multiple messages where longer than SMS limitations.

How it works

• Subscribes to every notifications.* path on the vessel.
• A notification is relayed only on an actual state transition - not on every repeated delta of an already-notified state - and only if it passes the filters below:
• Priority: only notifications at or above "Minimum priority" (default alert) are relayed.
• Path patterns: optional include/exclude regex lists against the notification path with the notifications. prefix stripped, e.g. navigation.anchor.maxRadius. Leave both empty to match every path ("globally").
• Clearing: with "Also notify when an alarm clears" on (default), a matched notification dropping back to normal/nominal also sends a text, even though that state alone is below "Minimum priority" - so "anchor alarm cleared" reaches you too.
• Rate limit: a sliding window caps SMS volume/cost (default 10 per 60 minutes). A notification at or above "Bypass priority" (default alarm) always sends regardless - so an anchor-drag emergency is never silently dropped because earlier chatter used up the quota.
• Retries: a failed send is retried (default 3 attempts, 30s apart) before being logged and given up on.
• Message text: with "Prefix the message with the alarm state" on (default), each text starts with the upper-cased state, e.g. [ALARM] navigation.anchor.maxRadius: dragging. Texts longer than "SMS length limit" (default 160 characters) are handled per "Over-length message handling": either truncated with a trailing ..., or split into multiple texts each suffixed ... {n}/{total} (e.g. ... 1/4) so the recipient can tell more parts follow.
• Recipients are texted individually and sequentially, not concurrently, so the rate limit stays accurate and the router's session token isn't raced.
• On restart, already-active notifications are silently re-learned (not re-texted) - a plugin restart doesn't re-fire an alarm you were already texted about.

Setup

1. Create a non-root RutOS user

Root credentials (the admin user) will work but best be avoided if possible - for best security, create a dedicated user or re-use an existing SignalK user and give it only the permissions it needs.

1. RutOS web UI: System -> Administration -> Users -> Add.
2. On that user's Permissions tab, confirmed by testing: grant either write access to All Pages, or specifically write access to the Services -> Mobile Utilities -> Messages -> Send and Services -> Mobile Utilities -> Messages -> Storage permission pages. No separate API-level ACL call is needed - it's just these two checkboxes in the UI.

Run teltonika-sms-cli acl <username> any time for a reminder of this.

2. Configure the plugin

In the SignalK admin UI, under this plugin's config:

| Field | Notes | | -------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Router base URL | Defaults to https://192.168.1.1, matching RutOS's own default HTTPS listener. Use a plain http://... URL only if that listener is disabled on your router. | | Allow self-signed cert | On by default - RutOS ships a self-signed HTTPS certificate out of the box. | | Username / Password | The non-root user from step 1. | | SMS modem | Leave blank to auto-pick on plugin start (and save it back here): the only modem if there's just one, otherwise the first (alphabetically) with a SIM inserted. Each option is shown as modem_id (modem_type), e.g. 1-1 (Quectel EC25). Tick "Refresh modem list on start" if the list looks empty or stale. | | Recipient phone numbers | International format only, e.g. +447123456789 - not a local/national number. | | Send a confirmation test message | Tick, save, and restart the plugin to text every recipient a one-off "it works" message. Clears itself automatically once that send succeeds - if it stays ticked, check the plugin log. |

3. Verify with the CLI

teltonika-sms-cli talks to the router directly, without needing a running SignalK server - useful for confirming credentials/modem/ACL before wiring up the plugin:

npm run cli -- login    --router-url https://192.168.1.1 --user <user> --password <password>
npm run cli -- modems   --router-url https://192.168.1.1 --user <user> --password <password>
npm run cli -- send "+447123456789" "test" --router-url https://192.168.1.1 --user <user> --password <password> --modem 1-1

(Once published/installed, drop npm run cli -- and call teltonika-sms-cli directly. Prefer $TELTONIKA_SMS_PASSWORD over --password so it isn't left in shell history.)

Roadmap

Not yet implemented (see design/intent.md):

• Two-way SMS - enquire a SignalK path's value, acknowledge an alarm by replying.
• Message inbox size / unread count as SignalK data paths.
• Use as a fail-through step after internet-based notification (4G/Starlink) fails.

Also for SignalK from Rhizomatics

• SignalK CLI

  • Query SignalK History API from command line
  • Output to console, CSV or Apache Arrow Feather dataframe
  • Automatic discovery of local SignalK server
  • Auto aggregation for min/avg/max of any path value

• Boat Tech Directory

  • Curated list of boat tech projects, products, standards, blogs, news and more
  • Available as Boat Tech Directory web site and in awesome list as Awesome Boat Tech

• signalk-datalab-plugin ALPHA

  • Python data notebooks using Marimo and WASM for easy (and advanced ) data analysis on SignalK data
  • Example notebook that pulls aggregate data out of the SignalK History API

• signalk-bluetti-plugin

  • Read Bluetti power station sensor data for battery level, solar input, inverter etc
  • Configuration for dozens of models
  • Some newer models using encrypted data will need a vendor-supplied key

• signalk-delta-squelch-plugin

  • Minimize noisy SignalK deltas and unnecessary database space/query time for analytics
  • Apply configurable rounding factor where SignalK precision exceeds the device resolution, e.g. GPS position
  • Skip updates within a configurable tolerance from last value, with heartbeat to maintain minimal stream
  • Reject implausible position changes from GPS spikes

• signalk-einklabel-plugin

  • Publish SignalK data to cheap eInk electronic shelf labels over BLE
  • Simple SVG templating, access to data paths plus Resources API
  • Scheduled based on time or change to a SignalK path
  • Handles ZhunyCo BLE labels and extensible for other vendors
  • Also available signalk-einklabel-genai-plugin to generate ESL labels from a configurable LLM prompt