This repository contains the (working) specification for Signal K, defined in JSON Schema files.
The Free and Open Source universal marine data exchange
Signal K is about publishing a common modern and open data format for marine use. A format for the modern boat, compatible with NMEA, friendly to WiFi, cellphones, tablets, and the Internet. A format available to everyone, where anyone can contribute.
Find out more at signalk.org. Then join the mailinglist by sending an email to signalk+subscribe@googlegroups.com or follow the discussion via the Signal K Google Groups forum.
The master branch contains the latest version of the Schema. When making
changes, please clone this repo to your local machine and set up a new branch
(git checkout -b branch_name). Send in a pull request for every change, put
it up for discussion in the mailing list and then (when a consensus has been
reached) merge it into master.
The gh-pages branch contains the currently published version of the schema
and specification. Documentation is generated with Gitbook and published at
http://signalk.org/specification/master/. Documentation is published on the web
with a single npm command:
$ npm run docs:publish
See below for details.
The documentation .md sources are at https://github.com/SignalK/specification/tree/master/gitbook-docs.
Requires separate installation of ebook-convert, see
https://toolchain.gitbook.com/ebook.html.
npm run docs:servefor local previewnpm run docs:allto generate locallynpm run docs:publishto publish in gh-pages.
Validation against Signal K schema can be done
- with a command line validator accepting JSON from stdin
- by explicitly calling validate packaged as an npm module
- by using a Chai assertion, available in the npm module
As you can see in the example below the current implementation assumes that the input is a subtree under vessels.mmsi path.
echo '{"navigation":{"courseOverGroundTru":{"value":70.1,"source":{"label":"","type":"NMEA2000","pgn":"130577","src":"160"},"timestamp":"2014-08-15-10:01:35.236"},"speedOverGround":{"value":0.01,"source":{"label":"","type":"NMEA2000","pgn":"130577","src":"160"},"timestamp":"2014-08-15-10:01:35.236"}}}' | bin/validate.js
Unknown property (not in schema):/vessels/230099999/navigation/courseOverGroundTru
var validate = require('signalk-schema').validate;
var result = validate(msg);
result.errors.forEach(function(error) {
console.error(error.message + ':' + error.dataPath);
});chai.use(require('signalk-schema').chaiModule);
tree.should.be.validSignalK;