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iNavx works fine when using the built in GPS on my iPad 2, but when I connect it to my Brookhouse iMux ST the COG is 180 degrees out and the 'own vessel' symbol points the wrong way.
COG on my Seatalk instruments displays correctly so it is within iNavx that it is going astray.

Has anyone else had this?

Actually the Brookhouse iMux converts the SeaTalk to NMEA-0183 and then iNavX processes the NMEA-0183. I would suspect the error is occurring in that translation process.


iNavX by default will use HDG instead of COG to orient the position icon. So it may be that HDG is incorrect from SeaTalk to NMEA-0183. Do you see HDG, HDT or HDM in the Instruments view or banner? If so recommend you try turning off the "HDG", "HDM", and "HDT" in the "Instruments" view and see if this fixes the orientation problem. Also toggle the "LinK" button in the iNavX TCP/IP NMEA Client as this resets the values (COG, HDG, SOG, etc.). Lastly, make sure "Location Services" is set to "OFF" in the iNavX TCP/IP NMEA Client, so iNavX knows to use the NMEA-0183 from the iMux instead of the built in GPS receiver.

This is the first ever I have heard of COG being incorrect from the Brookhouse iMux.

I'm having the same problem, but my COG is off by about 50 degrees. Has anyone confirmed that the process on the previous post fixes the problem?

Brian

Keep in mind that COG is only valid when underway as it requires a changing position to compute.

HDG is correct, it's only COG that's wrong. I'll take this up with Brookhouse.
Thanks

Hello,

I'm having the same problem...
My seatalk instruments displays a cog very different than the one displayed on the instrument page
The hdm is Normal , but the boat on the map point to the cog, even after disabling cog in the instruments view... Location service is set to off.

Any idea how to fix it?
Thank you, Simon

What would be most helpful is someone who is seeing this problem to post the NMEA data iNavX is receiving. iNavX running on the iPad has an "Email" button in the "TCP/IP NMEA Client". Use this to send a copy to yourself then post in this thread. From this NMEA data I might be able to see what is going on.

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIRMC,090500,A,4247.880,N,01723.700,E,4.5,1533589.4,150812,0.0,W,A*1D

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIMWV,12.0,R,8.0,N,A*06

$IIVWR,12.0,R,8.0,N,,,,*74

$IIHDM,43.0,M*15

$IIRSA,0.0,A,,*2F

$IIMTW,40.0,C*17

$IIMTW,104.0,F*23

$IIVTG,1533589.4,T,47.0,M,4.5,N,,*0A

$IIRMC,090500,A,4247.881,N,01723.709,E,4.5,1533589.4,150812,0.0,W,A*15

$IIRMB,A,,L,,,,,,,,,,V*2A

--> DISCONNECTING
--> DISCONNECTED
************************************
--> CONNECTING (TCP)
--> CONNECTED
$IIRMC,090540,A,4247.917,N,01723.756,E,4.6,1533585.4,150812,0.0,W,A*1A

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIHDM,37.0,M*16

$IIRSA,0.0,A,,*2F

$IIRMC,090540,A,4247.910,N,01723.750,E,4.6,1533585.4,150812,0.0,W,A*1B

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIVHW,,,37.0,M,4.8,N,,*72

$IIMTW,40.0,C*17

$IIMTW,104.0,F*23

$IIVTG,1533584.4,T,42.0,M,4.6,N,,*01

$IIRMC,090540,A,4247.918,N,01723.757,E,4.6,1533584.4,150812,0.0,W,A*15

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIHDM,37.0,M*16

$IIRSA,0.0,A,,*2F

$IIDBT,117.1,f,36.5,M,,F*09

$IIMTW,34.0,C*14

$IIMTW,94.0,F*1B

$IIVTG,1533584.4,T,42.0,M,4.6,N,,*01

$IIRMC,090540,A,4247.919,N,01723.758,E,4.6,1533584.4,150812,0.0,W,A*1B

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIHDM,37.0,M*16

$IIRSA,0.0,A,,*2F

$IIVHW,,,37.0,M,4.7,N,,*7D

$IIDBT,116.8,f,36.5,M,,F*01

$IIMWV,17.0,R,7.6,N,A*0A

$IIVWR,17.0,R,7.6,N,,,,*78

$IIMTW,39.0,C*19

$IIMTW,103.0,F*24

$IIVTG,1533584.4,T,42.0,M,4.6,N,,*01

$IIRMC,090540,A,4247.920,N,01723.759,E,4.6,1533584.4,150812,0.0,W,A*10

$IIRMB,A,,L,,,,,,,,,,V*2A

$IIHDM,37.0,M*16

$IIRSA,0.0,A,,*2F



Cog was aproximatively 340 and hdm 40

Thanks a lot,
Simon

The first part (before the deconnexion/reconnexion) is when location service was activated , the second is when it's desactivated

I notice in the NMEA sentences which have COG (RMC and VTG) that COG is erroneous value of: 1533584.4

I will take this up with Brookhouse and see if they know what is going on.

That's very nice, thanks!

Brookhouse have informed me there is a firmware update available that corrects this problem. Please contact Brookhouse directly to get more details. In iNavX 3.5.8, I will check that COG is a validate the value as between 0 - 360 before it's display.

Thank you very much!!
(what email adress do you use to contact them?
I tried support@brookhouseonline.com one week ago to ask them about the cog problem, I never had a response...)

Simon.