🐛 Bug Report: NMEA RMC Message Date and Time appears to be malformed

[KrisKnez]

Summary

Bridge Command currently emits malformed RMC (Recommended Minimum Navigation Information) sentences: the UTC time (field 1) and date (field 9) are empty, which violates the NMEA 0183 spec and causes receivers to reject the data.

Received RMC Message

$GPRMC,.00,A,5001.357,N,00959.010,W,0.2,154.3,,,,A,S*33

Note the missing hhmmss.ss after the first comma and the four consecutive commas before the mode flag, where ddmmyy should be.

Expected RMC Message

$GPRMC,121028.74,A,6054.34203,N,02234.57962,E,0.0,236.1,100725,007.1,E,A*36

Environment

Bridge Command Version: 5.10.1
OS: Windows 11 Pro 24H2

[KrisKnez]

I can see that the message is supposed to be correctly generated:

bc/src/NMEA.cpp

Line 424 in 96e83b7

snprintf(messageBuffer,maxSentenceChars,"$GPRMC,%s%s%s.00,A,%02u%06.3f,%c,%03u%06.3f,%c,%.1f,%.1f,%s%s%s,,,A,S",hour,min,sec,latDegrees,latMinutes,northSouth,lonDegrees,lonMinutes,eastWest,sog,cog,year,mon,mday); //FIXME: SOG -> knots, COG->degrees

I am not sure what is causing this issue.

[bridgecommand]

@KrisKnez, thanks for reporting this. The date and time information should have been included, but there was an error in the code, which should be fixed by #82.

[KrisKnez]

@bridgecommand Would it be possible to make a release build because the latest one as far as I see does not include this fix.

[bridgecommand]

@KrisKnez, thanks for the reminder. I am in the process of releasing 5.10.3, which will include this fix. The Windows build is at http://prerelease.bridgecommand.co.uk/BridgeCommand5.10.3.exe

There's also a Linux (AMD64) deb there, but I haven't yet tested it.

When I have generated the macOS and Linux ARM builds (for Raspberry Pi and similar), 5.10.3 will also be on the main download site, but this may be in a week or so.

[bridgecommand]

@KrisKnez, the full 5.10.3 release, including the NMEA fix is now on the Bridge Command download site at https://www.bridgecommand.co.uk/Download

Thanks again for reporting this.