SignalK to NMEA 2000 Plugin - Wind conversion error
Hello,
My NMEA 0183 wind instrument (nasa marine 5wire) outputs the wind direction in +/- rads off the bow. Open Plotter correctly interprets this but when the SignalK to NMEA 2000 plugin converts it to 0-360 degrees format for NMEA 2000 it is outputting a negative number eg -90 degrees
When this data is picked up by my B&G chart plotter the wind direction is flipped by 180 degrees.
Here is the debug log for the plugin:
Jun 10 16:20:54 2025-06-10T15:20:54.605Z signalk-to-nmea2000 environment.wind.angleApparent,environment.wind.speedApparent:-0.349065850478568,3.446778650961703
Jun 10 16:20:54 2025-06-10T15:20:54.606Z signalk-to-nmea2000 emit nmea2000JsonOut {"pgn":130306,"Wind Speed":3.446778650961703,"Wind Angle":5.934119456701018,"Reference":2}
I am using RP5 with the most recent OpenMarine image. Signal K seems to be a special version and the data fiddler doesnt have the functionality suggested by Chat GPT to adjust the output.
I have posted on the GitHub for the plugin but no response received.
Very grateful for any help.
John
1 Reply
I sorted it.. not sure how. Just deleted and reinstalled the plugin. I understand the NMEA 2000 protocol is for apparent wind to be in rads off the bow as a positive number. My Vulcan chart plotter converts that to +/- degrees off the bow which is where my confusion arose when trying to investigate why it was flipped. It doesnt explain why the wind was flipped in the first place but it has resolved itself now.