convert ROT from/to, add conv doc

lib/boatData/GwBoatData.h

@@ -21,6 +21,7 @@ class GwBoatItemBase{
         GWSC(kelvinToC);
         GWSC(mtr2nm);
         GWSC(formatDop);
+        GWSC(formatRot);
         typedef std::vector<GwBoatItemBase*> GwBoatItemMap;
     protected:
         unsigned long lastSet=0;
@@ -224,6 +225,7 @@ class GwBoatData{
     GWBOATDATA(double,AWA,4000,formatWind)
     GWBOATDATA(double,Heading,4000,formatCourse) //true
     GWBOATDATA(double,MagneticHeading,4000,formatCourse)
+    GWBOATDATA(double,ROT,4000,formatRot)
     GWBOATDATA(double,Variation,4000,formatCourse)
     GWBOATDATA(double,Deviation,4000,formatCourse)
     GWBOATDATA(double,HDOP,4000,formatDop)

lib/nmea0183ton2k/NMEA0183DataToN2K.cpp

@@ -714,6 +714,18 @@ private:
         send(n2kMsg);
     }
 
+    void convertROT(const SNMEA0183Msg &msg){
+        double ROT=NMEA0183DoubleNA;
+        if (! NMEA0183ParseROT_nc(msg,ROT)){
+            LOG_DEBUG(GwLog::DEBUG,"unable to parse ROT %s",msg.line);
+            return;
+        }
+        if (! updateDouble(boatData->ROT,ROT,msg.sourceId)) return;
+        tN2kMsg n2kMsg;
+        SetN2kRateOfTurn(n2kMsg,1,ROT);
+        send(n2kMsg);
+    }
+
 //shortcut for lambda converters
 #define CVL [](const SNMEA0183Msg &msg, NMEA0183DataToN2KFunctions *p) -> void
     void registerConverters()
@@ -777,6 +789,9 @@ private:
         converters.registerConverter(
             129025UL,
             String(F("GLL")), &NMEA0183DataToN2KFunctions::convertGLL); 
+        converters.registerConverter(
+            127251UL,
+            String(F("ROT")), &NMEA0183DataToN2KFunctions::convertROT);     
         unsigned long *aispgns=new unsigned long[7]{129810UL,129809UL,129040UL,129039UL,129802UL,129794UL,129038UL};
         converters.registerConverter(7,&aispgns[0],
             String(F("AIVDM")),&NMEA0183DataToN2KFunctions::convertAIVDX);

lib/nmea2kto0183/N2kDataToNMEA0183.cpp

@@ -73,13 +73,13 @@ private:
             return;
         maxItem->updateMax(item->getData(),sourceId);
     }
-    void updateDouble(GwBoatItem<double> *item, double value)
+    bool updateDouble(GwBoatItem<double> *item, double value)
     {
         if (value == N2kDoubleNA)
-            return;
+            return false;
         if (!item)
-            return;
+            return false;
-        item->update(value,sourceId);
+        return item->update(value,sourceId);
     }
     
     unsigned long LastPosSend;
@@ -1017,6 +1017,19 @@ private:
         if (DaysSince1970 != N2kUInt16NA) boatData->DaysSince1970->update(DaysSince1970,sourceId);
         if (LocalOffset != N2kInt16NA) boatData->Timezone->update(LocalOffset,sourceId);
     }
+    void HandleROT(const tN2kMsg &msg){
+        unsigned char SID=0;
+        double ROT=N2kDoubleNA;
+        if (! ParseN2kRateOfTurn(msg,SID,ROT)){
+            LOG_DEBUG(GwLog::DEBUG,"unable to parse PGN %d",msg.PGN);
+            return;
+        }
+        if (!updateDouble(boatData->ROT,ROT)) return;
+        tNMEA0183Msg nmeamsg;
+        if (NMEA0183SetROT(nmeamsg,ROT,talkerId)){
+            SendMessage(nmeamsg);
+        }
+    }
 
 
     void registerConverters()
@@ -1041,6 +1054,7 @@ private:
       converters.registerConverter(129033UL, &N2kToNMEA0183Functions::HandleTimeOffset);
       converters.registerConverter(129539UL, &N2kToNMEA0183Functions::HandleDop);
       converters.registerConverter(129540UL, &N2kToNMEA0183Functions::HandleSats);
+      converters.registerConverter(127251UL, &N2kToNMEA0183Functions::HandleROT);
 #define HANDLE_AIS
 #ifdef HANDLE_AIS
       converters.registerConverter(129038UL, &N2kToNMEA0183Functions::HandleAISClassAPosReport);  // AIS Class A Position Report, Message Type 1