feature: limit the transmission rates of pgns per the n2k spec

conversions/ais.js

@@ -50,6 +50,7 @@ module.exports = (app, plugin) => {
     sourceType: 'onDelta',
     //outputType: 'buffer',
     optionKey: 'AISv2',
+    pgns: [ static_pgn, position_pgn, aton_pgn ],
     callback: (delta) => {
       var selfContext = 'vessels.' + app.selfId
 
@@ -191,11 +192,11 @@ function generatePosition(vessel, mmsi, delta) {
       status = 0
     }
 
-    if ( cog > Math.PI*2 ) {
+    if ( cog >= Math.PI*2 ) {
       cog = undefined
     }
 
-    if ( heading > Math.PI*2 ) {
+    if ( heading >= Math.PI*2 ) {
       heading = undefined
     }
 

conversions/battery.js

@@ -15,6 +15,7 @@ module.exports = (app, plugin) => {
   return {
     title: 'Battery (127506 & 127508)',
     optionKey: 'BATTERYv2',
+    pgns: [127506, 127508],
     context: 'vessels.self',
     properties: {
       batteries: {

conversions/cogSOG.js

@@ -6,6 +6,7 @@ module.exports = (app, plugin) => {
   return {
     title: 'COG & SOG (129026)',
     optionKey: 'COG_SOGv2',
+    pgns: [ 129026 ],
     keys: ["navigation.courseOverGroundTrue", "navigation.speedOverGround"],
     callback: (course, speed) => {
       try {

conversions/depth.js

@@ -4,6 +4,7 @@ module.exports = (app, plugin) => {
   return {
     title: 'Depth (128267)',
     optionKey: 'DEPTHv2',
+    pgns: [ 128267 ],
     keys: ["environment.depth.belowTransducer"],
     callback: (belowTransducer) => {
       var surfaceToTransducer = _.get(app.signalk.self,

conversions/engineParameters.js

@@ -27,6 +27,7 @@ module.exports = (app, plugin) => {
   return [{
     title: 'Temperature, exhaust (130312)',
     optionKey: 'EXHAUST_TEMPERATURE',
+    pgns: [ 130312 ],
     context: 'vessels.self',
     properties: {
       engines: {
@@ -74,6 +75,7 @@ module.exports = (app, plugin) => {
   {
     title: 'Engine Parameters (127489,127488)',
     optionKey: 'ENGINE_PARAMETERS',
+    pgns: [ 127489, 127488 ],
     context: 'vessels.self',
     properties: {
       engines: {

conversions/gps.js

@@ -1,11 +1,10 @@
 const _ = require('lodash')
 
 module.exports = (app, plugin) => {
-  var lastUpdate = null
-
   return {
     title: 'Location (129025,129029)',
     optionKey: 'GPS_LOCATIONv2',
+    pgns: [ 129025, 129029 ],
     keys: ["navigation.position"],
     callback: (position) => {
       //app.debug(`position: ${JSON.stringify(position)}`)
@@ -17,38 +16,31 @@ module.exports = (app, plugin) => {
         }
       ]
 
-
-      if (
-        lastUpdate == null ||
-          (new Date().getTime() - lastUpdate.getTime()) > 1000
-      )  {
-        lastUpdate = new Date()
-
-        var dateObj = new Date();
-        var date = Math.trunc(dateObj.getTime() / 86400 / 1000);
-        var time =
-            dateObj.getUTCHours() * (60 * 60) +
-            dateObj.getUTCMinutes() * 60 +
-            dateObj.getUTCSeconds();
-
-        res.push({
-          pgn: 129029,
-          Date: date,
-          Time: time,
-          Latitude: position.latitude,
-          Longitude: position.longitude,
-          'GNSS type': 'GPS+SBAS/WAAS',
-          Method: 'DGNSS fix',
-          Integrity: 'No integrity checking',
-          'Number of SVs': 16,
-          HDOP:0.64,
-          'Geoidal Separation': -0.01,
-          'Reference Stations': 1,
-          'Reference Station Type': 'GPS+SBAS/WAAS',
-          'Reference Station ID': 7
+      var dateObj = new Date();
+      var date = Math.trunc(dateObj.getTime() / 86400 / 1000);
+      var time =
+          dateObj.getUTCHours() * (60 * 60) +
+          dateObj.getUTCMinutes() * 60 +
+          dateObj.getUTCSeconds();
+
+      res.push({
+        pgn: 129029,
+        Date: date,
+        Time: time,
+        Latitude: position.latitude,
+        Longitude: position.longitude,
+        'GNSS type': 'GPS+SBAS/WAAS',
+        Method: 'DGNSS fix',
+        Integrity: 'No integrity checking',
+        'Number of SVs': 16,
+        HDOP:0.64,
+        'Geoidal Separation': -0.01,
+        'Reference Stations': 1,
+        'Reference Station Type': 'GPS+SBAS/WAAS',
+        'Reference Station ID': 7
           //'Age of DGNSS Corrections': 
-        })
-      }
+      })
+
       return res
     }
   }

conversions/heading.js

@@ -4,6 +4,7 @@ module.exports = (app, plugin) => {
     pgn: 127250,
     title: 'Heading (127250)',
     optionKey: 'HEADINGv2',
+    pgns: [ 127250 ],
     keys: [
       "navigation.headingMagnetic",
       'navigation.magneticVariation'

conversions/speed.js

@@ -4,6 +4,7 @@ module.exports = (app, plugin) => {
     pgns: [ 128259 ],
     title: 'Speed (128259)',
     optionKey: 'SPEED',
+    pgns: 128259,
     keys: ["navigation.speedThroughWater"],
 
     callback: (speed) => {

conversions/systemTime.js

@@ -5,6 +5,7 @@ module.exports = (app, plugin) => {
     sourceType: 'timer',
     interval: 1000,
     optionKey: 'SYSTEM_TIMEv2',
+    pgns: [ 126992 ],
     callback: (app) => {
       var dateObj = new Date();
       var date = Math.trunc(dateObj.getTime() / 86400 / 1000);

conversions/tanks.js

@@ -15,6 +15,7 @@ module.exports = (app, plugin) => {
   return {
     title: 'Tank Levels (127505)',
     optionKey: 'TANKS',
+    pgns: [ 127505 ],
     context: 'vessels.self',
     properties: () => {
       var tanks = _.get(app.signalk.self, 'tanks')

conversions/temperature.js

@@ -15,6 +15,7 @@ module.exports = (app, plugin) => {
     pgn: 130312,
     title: 'Outside Temperature (130312)',
     optionKey: 'TEMPERATURE_OUTSIDE',
+    pgns: [ 130312 ],
     keys: [
       "environment.outside.temperature"
     ],
@@ -26,6 +27,7 @@ module.exports = (app, plugin) => {
     pgn: 130312,
     title: 'Inside Temperature (130312)',
     optionKey: 'TEMPERATURE_INSIDE',
+    pgns: 130312,
     keys: [
       "environment.inside.temperature"
     ],
@@ -37,6 +39,7 @@ module.exports = (app, plugin) => {
     pgn: 130312,
     title: 'Engine Room Temperature (130312)',
     optionKey: 'TEMPERATURE_ENGINEROOM',
+    pgns: [ 130312 ],
     keys: [
       "environment.inside.engineRoom.temperature"
     ],
@@ -48,6 +51,7 @@ module.exports = (app, plugin) => {
     pgn: 130312,
     title: 'Refridgerator Temperature (130312)',
     optionKey: 'TEMPERATURE_refridgerator',
+    pgns: [ 130312 ],
     keys: [
       "environment.inside.refrigerator.temperature"
     ],

conversions/wind.js

@@ -3,6 +3,7 @@ module.exports = (app, plugin) => {
   return {
     title: 'Wind (130306)',
     optionKey: 'WINDv2',
+    pgns: [ 130306 ],
     keys: ["environment.wind.angleApparent", "environment.wind.speedApparent"],
     callback: (angle, speed) => {
       try {

index.js

@@ -6,7 +6,9 @@ const path = require('path')
 const fs = require('fs')
 
 module.exports = function(app) {
-  var plugin = {};
+  var plugin = {
+    lastUpdates: {}
+  };
   var unsubscribes = [];
   var timers = []
   var conversions = load_conversions(app, plugin)
@@ -104,6 +106,7 @@ module.exports = function(app) {
           if ( subConversions != null ) {
             subConversions.forEach(subConversion => {
               var type = _.isUndefined(subConversion.sourceType) ? 'onValueChange' : subConversion.sourceType
+
               var mapper = sourceTypes[type]
               if ( _.isUndefined(mapper) ) {
                 console.error(`Unknown conversion type: ${type}`)
@@ -156,13 +159,22 @@ module.exports = function(app) {
   function processToN2K(pgns) {
     if ( pgns ) {
       pgns.filter(pgn => pgn != null).forEach(pgn => {
-        try {
-          app.debug("emit %j", pgn)
-          app.emit("nmea2000JsonOut", pgn);
-        }
-        catch ( err ) {
-          console.error(`error writing pgn ${JSON.stringify(pgn)}`)
-          console.error(err.stack)
+
+        const key = `${pgn.pgn}.${pgn.Instance}`
+        const lastUpdate = plugin.lastUpdates[key]
+        const rate = updateRates[pgn.pgn]
+        if ( !_.isUndefined(rate) && !_.isUndefined(lastUpdate) && Date.now() - lastUpdate < rate ) {
+          return
+        } else {
+          plugin.lastUpdates[key] = Date.now()
+          try {
+            app.debug("emit %j", pgn)
+            app.emit("nmea2000JsonOut", pgn);
+          }
+          catch ( err ) {
+            console.error(`error writing pgn ${JSON.stringify(pgn)}`)
+            console.error(err.stack)
+          }
         }
       })
     }
@@ -172,7 +184,9 @@ module.exports = function(app) {
     outputTypes[conversion.outputType](output)
   }
 
-  function mapBaconjs(conversion) {
+  function mapBaconjs(conversion, options) {
+    let lastUpdate
+
     unsubscribes.push(
       timeoutingArrayStream(
         conversion.keys,
@@ -187,7 +201,7 @@ module.exports = function(app) {
     );
   }
 
-  function mapOnDelta(conversion) {
+  function mapOnDelta(conversion, options) {
     app.signalk.on('delta', (delta) => {
       try {
         processOutput(conversion, conversion.callback(delta))
@@ -271,13 +285,28 @@ module.exports = function(app) {
     })
     const result = combinedBus.debounce(10)
     if (app.debug.enabled) {
-      unsubscribes.push(result.onValue(x => app.debug(`${keys}:${x}`)))
+      unsubscribes.push(result.onValue(x => app.debug(`${keys}:${JSON.stringify(x)}`)))
     }
     return result
   }
-
-};
+}
 
 
 const notDefined = x => typeof x === 'undefined'
 const isDefined = x => typeof x !== 'undefined'
+
+const updateRates = {
+  127506: 1500,
+  127508: 1500,
+  129026: 250,
+  128267: 1000,
+  130312: 2000,
+  127489: 500,
+  129025: 100,
+  129029: 1000,
+  127250: 100,
+  126992: 1000,
+  127505: 2500,
+  130306: 100
+}
+