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OSD sentence from navigation.headingmagnetic incorrect - Printable Version

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OSD sentence from navigation.headingmagnetic incorrect - looper - 2018-08-29

Compass Heading

Version: nOObs 1.0
HW: RPi 3

Trying to get data from IMU to output to a NMEA repeater.  Signal K sees the correct heading information, however the NMEA out stream shows a completely different number.

Image 1 shows the NMEA output of 4.8deg on the OSD stream

Image 2 shows navigation.headingtrue and navigation.headingmagnetic to be the correct numbers of roughly 270deg

Image 3 shows the configuration for the OSD stream in NMEA1083 config

What am I doing wrong that is causing the 270deg to be translated to 4deg?


RE: OSD sentence from navigation.headingmagnetic incorrect - PaddyB - 2018-08-29

(2018-08-29, 03:31 PM)looper Wrote: Compass Heading

Version: nOObs 1.0
HW: RPi 3

Trying to get data from IMU to output to a NMEA repeater.  Signal K sees the correct heading information, however the NMEA out stream shows a completely different number.

Image 1 shows the NMEA output of 4.8deg on the OSD stream

Image 2 shows navigation.headingtrue and navigation.headingmagnetic to be the correct numbers of roughly 270deg

Image 3 shows the configuration for the OSD stream in NMEA1083 config

What am I doing wrong that is causing the 270deg to be translated to 4deg?

The signalk display might be OK in degrees but I think it stores the data as radians - 360 degress is 2 x Pi radians. so you could try - is it expression? > heading magnetic *  180 / 3.14.


RE: OSD sentence from navigation.headingmagnetic incorrect - e-sailing - 2018-08-29

Paddy is right. The value is radiant not degrees.
In Signal K diagnostic you have switched on private unit disable it and you will see original Signal K values.
To build a nmea0183 sentence with the right value in degrees you can use a factor (as described above). Or you replace your x.x format with x.x|deg (picture 3).


RE: OSD sentence from navigation.headingmagnetic incorrect - PaddyB - 2018-08-29

Does it have to be OSD? Would HDM work? If so you could just use the signalk APP to do it. 

[Image: 27145294-e21dd896-513d-11e7-9ebc-1e1d4b6cf0db.png]


OSD sentence from navigation.headingmagnetic incorrect - tkurki - 2018-09-07

(2018-08-29, 11:23 PM)PaddyB Wrote: Does it have to be OSD? Would HDM work? If so you could just use the signalk APP to do it. 

Adding OSD to the list of supported conversions would also be very little work.




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