@signalk/nmea0183-signalk
Version:
A node.js/javascript parser for NMEA0183 sentences. Sentences are parsed to Signal K format.
88 lines • 3.64 kB
JavaScript
;
/**
* Copyright 2016 Signal K <info@signalk.org> and contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
var desc = Object.getOwnPropertyDescriptor(m, k);
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
const utils = __importStar(require("@signalk/nmea0183-utilities"));
/*
99 00 XX Compass variation sent by ST40 compass instrument
or ST1000, ST2000, ST4000+, E-80 every 10 seconds
but only if the variation is set on the instrument
Positive XX values: Variation West, Negative XX values: Variation East
Examples (XX => variation): 00 => 0, 01 => -1 west, 02 => -2 west ...
FF => +1 east, FE => +2 east ...
Corresponding NMEA sentences: RMC, HDG
Reference: http://www.thomasknauf.de/rap/seatalk2.htm
*/
const S99 = function (input, _session) {
const { parts, tags } = input;
// XX is an 8-bit two's complement value. Per the SeaTalk spec, a positive
// XX encodes West variation and a negative XX encodes East variation.
// Signal K uses the navigation convention (East positive, West negative),
// so the decoded byte must be negated.
const XX = parseInt(parts[2], 16);
const signed = XX > 127 ? XX - 256 : XX;
const magneticVariation = -signed;
const pathValues = [
{
path: 'navigation.magneticVariation',
value: utils.transform(utils.float(magneticVariation), 'deg', 'rad')
}
];
return {
updates: [
{
source: tags.source,
timestamp: tags.timestamp,
values: pathValues
}
]
};
};
exports.default = S99;
//# sourceMappingURL=0x99.js.map