MGL Avionics User Forum

I'm having trouble with my XTreme XMS G2 and it keeping time.

1) The battery seems to last less then 6 months to keep the RTC going.
2) I've added input from a GPS to supply details instead, for date/time and fuel calculations, but am having issues.

Currently I'm only sending the GGA and RMC NMEA messages, which should supply all needed to set date/time and show location and altitude.
I'd prefer not to have to send the extra GSA and GSV as they're not really needed, and when you're limited to 9600 baud (matching Autopilot, there is very little time capacity for all the messages, especially when receiving from all 3 GPS systems
But this is NOT the case.

The Zulu Time is being set correctly from from the GPS
The Zulu Date seems to be set to 0 Jan 2000 (when not then it becomes 4000!!!)
The GPS Altitude is never shown
The Local Time is completely out of whack and inconsistent with the +10Hrs Offset that it should be

The Speed, time remaining and range seem to work correctly in the Fuel Flow.

See attached images
https://photos.app.goo.gl/FeXmNdcM85o5p2uD8

Also, It would be really nice to know if/when the Firmware is updated on the website or when it was last updated.
It doesn't tell you, there is no date associated with the zip file to download, and if you don't remember to look at your own instrument, then you don't know what version you are currently running.

Hi Steve,

I had a look at the photos. Just a few things to check.

1) Please upgrade to the latest firmware (Version 2.16)
2) You are still transmitting the GPGSV message as the skyview and signal quality is still shown.
3) You can change the baud rate of the GPS receiver under the GPS setup.
4) I dont think you are transmitting the GPGGA message as the only field we get from this message is altitude.
5) The GPS needs a fix before the time is set.

Let me know on the above.

Regards,
Franz

Thanks for getting back to me.

1) Can you tell me where to get 2.16, as the website still shows 2.15 as the current firmware
Is there anywhere that explains what changes/fixes exist in any release?
2) I am currently transmitting all the following
GGA RMB RMC GSA GSV
I have tried with and without the GSV, but it didn't seem to make any difference
3) I can only change the baud rate to those speeds that all devices "sharing" the channel can accept.
Unfortunately my Auto Pilot won't accept faster than 9600
4) With the GGA above I am now seeing altitude, but the date is still wrong and LocalTime nothing related to Timezone
5) The GPS definitely has a fix

My understanding is the date should come from the RMC sentence.
My gps unit also has a ZDA sentence with date and time, but many units do not and I have no idea if the MGL unit would use it.

My unit also supports all 3 GPS systems (GP BD and GL) and sends GS

If you could tell me exactly which sentences are mandatory to get date/time/altitude and location) for distance to empty) to work that would be appreciated

and/or send me an example nmea data stream so i can check all fields that would also be appreciated

Steve

Here is a sample of a full set of NMEA data (static receiver)
maybe it'll help

I also have optional code that rebuilds the RMC, to include the magnetic declination

$GNZDA,052050.000,23,06,2024,00,00*49
$GNGGA,052051.000,3523.72382,S,14905.61291,E,1,12,1.6,647.9,M,19.1,M,,*52
$GPGSV,4,1,14,02,20,125,42,05,,,26,07,14,052,31,10,,,26,0*66
$GPGSV,4,2,14,13,,,27,14,54,137,40,17,82,044,30,19,61,343,28,0*5A
$GPGSV,4,3,14,21,11,136,26,22,66,189,31,28,,,24,30,,,32,0*68
$GPGSV,4,4,14,193,,,25,195,16,350,31,0*52
$BDGSV,1,1,02,23,54,100,32,28,50,018,36,0*75
$GLGSV,2,1,06,78,,,25,66,14,216,,79,,,25,65,26,266,,0*78
$GLGSV,2,2,06,84,43,122,31,85,45,036,29,0*75
$GNRMC,052051.000,A,3523.72382,S,14905.61291,E,0.00,0.00,230624,,,A,V*1A
$GNVTG,0.00,T,,M,0.00,N,0.00,K,A*23
$GNZDA,052051.000,23,06,2024,00,00*48
$GNGGA,052052.000,3523.72382,S,14905.61290,E,1,12,1.6,647.9,M,19.1,M,,*50
$GPGSV,4,1,14,02,20,125,42,05,,,26,07,14,052,31,10,,,26,0*66
$GPGSV,4,2,14,13,,,27,14,54,137,40,17,82,044,30,19,61,343,28,0*5A
$GPGSV,4,3,14,21,11,136,26,22,66,189,31,23,,,25,30,,,32,0*62
$GPGSV,4,4,14,193,,,25,195,16,350,31,0*52
$BDGSV,1,1,03,01,,,33,23,54,100,32,28,50,018,36,0*75
$GLGSV,2,1,06,78,,,25,66,14,216,,79,,,25,65,26,266,,0*78
$GLGSV,2,2,06,84,43,122,31,85,45,036,29,0*75
$GNRMC,052052.000,A,3523.72382,S,14905.61290,E,0.00,0.00,230624,,,A,V*18
$GNVTG,0.00,T,,M,0.00,N,0.00,K,A*23
$GNZDA,052052.000,23,06,2024,00,00*4B
$GNGGA,052053.000,3523.72383,S,14905.61289,E,1,12,1.6,647.9,M,19.1,M,,*58
$GPGSV,3,1,12,02,20,125,42,05,,,26,07,14,052,31,13,,,27,0*65
$GPGSV,3,2,12,14,54,137,40,17,82,044,30,19,61,343,28,21,11,136,26,0*6F
$GPGSV,3,3,12,22,66,189,31,23,,,25,30,,,32,195,16,350,31,0*5E
$BDGSV,1,1,03,01,,,33,23,54,100,32,28,50,018,36,0*75
$GLGSV,2,1,06,78,,,25,66,14,216,,79,,,27,65,26,266,,0*7A
$GLGSV,2,2,06,84,43,122,31,85,45,036,30,0*7D
$GNRMC,052053.000,A,3523.72383,S,14905.61289,E,0.00,0.00,230624,,,A,V*10
$GNVTG,0.00,T,,M,0.00,N,0.00,K,A*23
$GNZDA,052053.000,23,06,2024,00,00*4A

Hi Steve,

Thanks for posting the GPS data - it helped a lot.

We have updated the GPS sentences to include the GN sentences. The EMS was only looking for GPS messages and I seen you are using a gps receiver that includes the BeiDou satellites

Code has been uploaded - version 2.17

Let me know how it goes.

Regards,
Franz

HI guys,

Thanks for the firmware update. It has greatly improved the system, but some minor issues.

The issue with the time/date and localtime are now all correct.

the continuing situation.
1) The Altitude is ONLY displayed if I include the GSA and GSV sentences, even though it is part of the GGA sentence
2) when I include the GSA and GSV, the screen flashes alternately between red and green for the satellites

As I'd prefer to only send GGA and RMC, neither of these are critical, but nice to haves

Example of preferred sentence transmission, only needing GGA and RMC

$GPGGA,014450.000,3523.72104,S,14905.62156,E,1,25,0.6,669.7,M,19.1,M,,*4B
$GPRMC,0144,A,3523.72104,S,14905.62156,E,0.0,119.3,140724,12.7,E,A,V*4F
$GPGGA,014451.000,3523.72103,S,14905.62156,E,1,25,0.6,669.7,M,19.1,M,,*4D
$GPRMC,0144,A,3523.72103,S,14905.62156,E,0.0,119.3,140724,12.7,E,A,V*48
$GPGGA,014452.000,3523.72103,S,14905.62156,E,1,25,0.6,669.7,M,19.1,M,,*4E
$GPRMC,0144,A,3523.72103,S,14905.62156,E,0.0,119.3,140724,12.7,E,A,V*48
$GPGGA,014453.000,3523.72102,S,14905.62155,E,1,25,0.6,669.7,M,19.1,M,,*4D
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014454.000,3523.72102,S,14905.62155,E,1,25,0.6,669.7,M,19.1,M,,*4A
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014455.000,3523.72102,S,14905.62155,E,1,25,0.6,669.6,M,19.1,M,,*4A
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014456.000,3523.72102,S,14905.62155,E,1,25,0.6,669.6,M,19.1,M,,*49
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014457.000,3523.72102,S,14905.62155,E,1,25,0.6,669.6,M,19.1,M,,*48
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014458.000,3523.72102,S,14905.62155,E,1,25,0.6,669.6,M,19.1,M,,*47
$GPRMC,0144,A,3523.72102,S,14905.62155,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014459.000,3523.72102,S,14905.62154,E,1,25,0.6,669.6,M,19.1,M,,*47
$GPRMC,0144,A,3523.72102,S,14905.62154,E,0.0,119.3,140724,12.7,E,A,V*4B
$GPGGA,014500.000,3523.72102,S,14905.62154,E,1,25,0.6,669.6,M,19.1,M,,*4A
$GPRMC,0145,A,3523.72102,S,14905.62154,E,0.0,119.3,140724,12.7,E,A,V*4A
$GPGGA,014501.000,3523.72101,S,14905.62153,E,1,25,0.6,669.6,M,19.1,M,,*4F
$GPRMC,0145,A,3523.72101,S,14905.62153,E,0.0,119.3,140724,12.7,E,A,V*4E
$GPGGA,014502.000,3523.72101,S,14905.62152,E,1,25,0.6,669.6,M,19.1,M,,*4D
$GPRMC,0145,A,3523.72101,S,14905.62152,E,0.0,119.3,140724,12.7,E,A,V*4F
$GPGGA,014503.000,3523.72101,S,14905.62151,E,1,26,0.5,669.6,M,19.1,M,,*4F
$GPRMC,0145,A,3523.72101,S,14905.62151,E,0.0,119.3,140724,12.7,E,A,V*4C


Example Including GSA and GSV sentences

$GPGGA,014333.000,3523.72088,S,14905.62170,E,1,26,0.5,670.3,M,19.1,M,,*44
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,21,05,15,252,27,07,55,110,37,08,28,129,37,0*60
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,25,17,19,357,40,0*68
$GPGSV,4,3,15,20,11,281,08,21,07,083,19,22,37,297,27,30,67,191,31,0*64
$GPGSV,4,4,15,194,55,318,34,195,07,352,28,199,43,325,29,0*6D
$GPRMC,0143,A,3523.72088,S,14905.62170,E,0.0,119.3,140724,12.7,E,A,V*49
$GPGGA,014334.000,3523.72088,S,14905.62169,E,1,26,0.5,670.2,M,19.1,M,,*4A
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,19,05,15,252,27,07,55,110,37,08,28,129,37,0*6B
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,27,17,19,357,40,0*6A
$GPGSV,4,3,15,20,11,281,08,21,07,083,19,22,37,297,27,30,67,191,31,0*64
$GPGSV,4,4,15,194,55,318,34,195,07,352,28,199,43,325,29,0*6D
$GPRMC,0143,A,3523.72088,S,14905.62169,E,0.0,119.3,140724,12.7,E,A,V*41
$GPGGA,014335.000,3523.72088,S,14905.62170,E,1,26,0.5,670.2,M,19.1,M,,*43
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,19,05,15,252,27,07,55,110,37,08,28,129,37,0*6B
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,27,17,19,357,40,0*6A
$GPGSV,4,3,15,20,11,281,08,21,07,083,19,22,37,297,27,30,67,191,31,0*64
$GPGSV,4,4,15,194,55,318,34,195,07,352,28,199,43,325,29,0*6D
$GPRMC,0143,A,3523.72088,S,14905.62170,E,0.0,119.3,140724,12.7,E,A,V*49
$GPGGA,014336.000,3523.72088,S,14905.62169,E,1,26,0.5,670.2,M,19.1,M,,*48
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,19,05,15,252,27,07,55,110,37,08,28,129,37,0*6B
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,28,17,19,357,40,0*65
$GPGSV,4,3,15,20,11,281,08,21,07,083,20,22,37,297,27,30,67,191,32,0*6D
$GPGSV,4,4,15,194,55,318,35,195,07,352,28,199,43,325,29,0*6C
$GPRMC,0143,A,3523.72088,S,14905.62169,E,0.0,119.3,140724,12.7,E,A,V*41
$GPGGA,014337.000,3523.72089,S,14905.62169,E,1,26,0.5,670.2,M,19.1,M,,*48
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,19,05,15,252,27,07,55,110,36,08,28,129,37,0*6A
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,28,17,19,357,40,0*65
$GPGSV,4,3,15,20,11,281,08,21,07,083,20,22,37,297,28,30,67,191,32,0*62
$GPGSV,4,4,15,194,56,318,35,195,07,352,28,199,43,325,29,0*6F
$GPRMC,0143,A,3523.72089,S,14905.62169,E,0.0,119.3,140724,12.7,E,A,V*40
$GPGGA,014338.000,3523.72090,S,14905.62169,E,1,26,0.5,670.2,M,19.1,M,,*4F
$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20
$GPGSV,4,1,15,02,05,068,19,05,15,252,27,07,55,110,36,08,28,129,37,0*6A
$GPGSV,4,2,15,09,32,021,36,13,23,223,24,14,62,280,28,17,19,357,40,0*65
$GPGSV,4,3,15,20,11,281,08,21,07,083,20,22,37,297,28,30,67,191,32,0*62
$GPGSV,4,4,15,194,56,318,35,195,07,352,28,199,43,325,29,0*6F
$GPRMC,0143,A,3523.72090,S,14905.62169,E,0.0,119.3,140724,12.7,E,A,V*48

NOTE: The previous NMEA sentences I had supplied were direct from the GPS chip. This version is from my device which filters and modifies then a little.

a) it changes the GN to GP, so that my old Autopilot recognizes them (as you had noticed similar)
b) adds the magnetic variation to the RMC (which the GPS chip was unaware of)

I had a bug where i was supplying the year as 2024, instead of 24, so it was incorrectly setting the year to 2020.
I have corrected this.

Hi Steve,

You need to send the GGA message so the Xtreme knows what fix it is. Once a 3d fix is obtained then the gps altitude will be displayed.

You are sending conflicting GSA messages:

$GPGSA,A,3,02,05,07,08,09,13,14,17,20,21,22,30,1.0,0.5,0.8,1*21
$GPGSA,A,3,11,12,23,39,40,43,,,,,,,1.0,0.5,0.8,4*2D
$GPGSA,A,3,78,79,69,88,68,,,,,,,,1.0,0.5,0.8,2*20

I assume you are replacing the GN and BD GSA prefix's to GP. This will cause the Xtreme to flash between green and red as it is getting conflicting information about the satellites. You will have to stick to GP GSA and GP GSV messages as these are paired.

Regards,
Franz

Thanks for the feedback and update.

I'll investigate and resolve my conflict issues, but think I'll leave the GSA and GSV messages turned off anyway to keep the serial data to the minimum necessary for the AP, clock and Fuel system.

Especially since my AP is limited to 9600 baud.

Another option will be to only switch the GGA and RMC sentences to GP prefix and leave all the satellite ones (GSA and GSV) as original.

might try both

thanks again.
Steve