Will GPSOut work with Garmin eTrex Legend in FlightSim 2004?

[squale]

Just wondering if this will work with my Garmin eTrex legend if I hook it up to FlightSim2004 through the serial cable that came with the eTrex?

Thanks

[Pete Dowson]

Just wondering if this will work with my Garmin eTrex legend if I hook it up to FlightSim2004 through the serial cable that came with the eTrex?

No, I don't think so. I have an Etrex Vista, and certainly that has no mode for NMEA input.

Pete

[squale]

okay because looking at the Serial Data Format option on the eTrex Legend, you can choose between the following:

-Garmin

-Garmin DGPS

-NMEA In/NMEA Out

-Text Out

-RTCM In

-RTCM In/NMEA Out

-RTCM In/Text Out

-None

I thought by choosing the "NMEA In/NMEA Out" option this meant I can also IMPORT NMEA data, but you are saying no huh?

[Pete Dowson]

I thought by choosing the "NMEA In/NMEA Out" option this meant I can also IMPORT NMEA data, but you are saying no huh?

Hmmm. Interesting. Mine has an identical list to yours, but in that position only NMEA out is listed, no "in" at all.

Try it. What can you lose?

How do you tell it to ignore its own aerial readings from satellites? The NMEA out option has to work to do the reverse -- i.e. feed Etrex positional data to a PC or whatever, so there has to be another option to switch someplace.

Regards,

Pete

[squale]

well I can try it, but have never used this utility before so really don't know what I"m doing, but will give it a shot. I don't know like you said what mode to put it in whether I choose GPS Off, etc.

[BrunoBL]

Hi,

It has been posted in other threads that aviation GPS units that do talk to GPSout must be put in "simulator mode" in order to turn off their internal receivers. You can give it a shot in your unit and see if it works. Please don't forget to keep us informed of your results!

At any rate, I too have been intrigued by "NMEA IN/OUT" being only "OUT" in fact, since it seems that most receivers which can be fed from external NMEA sources are those with "aviation" or AV400 interface (thanks for implementing that in GPSOut, Pete).

One user did report here that his marine receiver (a bulky one, too, according to him) can handle NMEA IN from external devices. But this does not seem to be the norm with handhelds.

Best regards,

Bruno.

[squale]

OKAY, I tested this in DEMO mode, using NMEA In/Out at 4800 speed. I set in the gpsout.ini file the following:

[GPSout]

Sentences=RMC,RMA,PGRMZ,GLL,VTG,GGA,GSA

Interval=1000

Port=COM1

Speed=4800

I know that the gps is talking to the computer because through EasyGPS software I can load waypoints, routes, etc.

Well anyhow, I opened up Flight Sim 2004, started flying and it didn't correspond to what I was seeing, my GPS in demo mode just slowly moves along at 20kt/hour and goes straight to the destination you choose. So the answer in short is NO I don't think FlightSimulator is sending the gps any info, and if it is the gps is not doing anything with it.

What is the "RTCM In" mode used for on the eTrex Legend GPS by the way, I haven't tried that one.

[Pete Dowson]

OKAY, I tested this in DEMO mode, using NMEA In/Out at 4800 speed.

You'd need a simulation mode rather than a demo mode, I think.

Anyway, I just checked my Etrex Vista. This also says "NMEA In/NMEA Out" in the selection menu in the device itself. However, the manual definitely lists this as "NMEA Out" only. There's no mention of NMEA In.

I think it's a little bug in the firmware in the device itself -- they have the menu wrong. The manual is correct.

So the answer in short is NO I don't think FlightSimulator is sending the gps any info, and if it is the gps is not doing anything with it.

GPSout will be sending data -- rather a lot in fact with all those options you've selected! You can check what happens on a serial port using a neat little free program called "PortMon" from http://www.systeminternals.com.

What is the "RTCM In" mode used for on the eTrex Legend GPS by the way, I haven't tried that one.

Not sure what the initials are, but it is related to utilising external receivers to get more accurate positioning -- "differential beacon receivers" according to the Garmin manual. The unit will be using satellite signals from another receiver as well as its own for determining positions very accurately -- probably a similar technique to using more than one radio telescope to get more accurate space readings or images. I think that sort of stuff is used by surveyors and the like when laying out building plots and so on. It's no use for FS.

Regards,

Pete

[dfournie]

RTCM is the Radio Technical Commission for Maritime Services. They more-or-less set the standards for shipborne GPS precision receivers. Using a radio frequency based diferential GPS ground station with a known location, a GPS unit set up in RTCM IN/OUT mode, can tune to this ground station frequency for precise correction of the GPS induced wandering that is introduced into the GPS satellite system. Mostly used in ship harbors by harbor pilots for precision navigation in tight areas.

At work I use a GPS constellation simulator. It is a UNIX based system with hardware/software that correctly models the entire GPS satellite system for a given location/time. It outputs an RF signal that can be connected to any GPS antenna-in port. Using conrol software we can "drive" the simulator around and simulate movement. In comparing Pete's GPSOUT.DLL from flight sim to the same data coming from the simulator we see virtually no difference in location and tracking. Unless Microsoft plans on making the GPSOUT feature part of their next Flt Sim 200X release, you can't beat what Pete has done.

[squale]

yes it certainly is a GREAT idea, I just wish I could use my Garmin eTrex Legend with it :(

Well maybe I will just have to wait until I get my PDA + GPS + AnywhereMap system going..

[dfournie]

I've tried GPSOUT.DLL into about 10 GPS different receivers that have NMEA input capability. All have worked perfectly, as it appears Pete is strictly adhering to the NMEA spec for the produced sentences. Unfortunately for the normal user, of these 10, only 2 are consumer level systems - 1 aviation and 1 marine. The other 8 are military.

[squale]

Say you got a Dell Axim x30 624mhz gps with a USB cradle. Is there a way I can use GPS out to feed into my PDA? or do you NEED to have a serial connection for this to work?

I want to use something like PocketFMS on my PDA and feed gps data into it from FlightSim but unfortunately my PDA only connects via a USB cradle?

Pete, do they make an adapter where I can plug a male USB cable into it and get a female 9-pin serial end out to plug into my computer's serial port? I think this way might work right?

[dfournie]

The original NMEA specification is ONLY for a serial connection at 4800bps. My Sony PDA is USB, but I was able to find an adapter to go from the Sony proprietary connector to a DB9 male serial. I just threw a null modem connector in line and it worked. I believe there is a newer NMEA 2000 specification on the horizon that essentially puts an ethernet network on the ship/vehicle and sends the NMEA data zipping around at 10 Mbits.

[Pete Dowson]

Say you got a Dell Axim x30 624mhz gps with a USB cradle. Is there a way I can use GPS out to feed into my PDA? or do you NEED to have a serial connection for this to work?

Many USB connections emulate ordinary serial ports (COMn) at the PC end. See if yours is listed in the Settings-Control Panel-System-Hardware-Device manager list under "Ports COM and LPT" or similar.

I know my iPaq isn't, nor my Garmin iQue 3600. :cry:

do they make an adapter where I can plug a male USB cable into it and get a female 9-pin serial end out to plug into my computer's serial port? I think this way might work right?

Things aren't that easy. If the socket on the PDA is true USB the electrical and protocol characteristics are entirely different.

Regards,

Pete

[tuomas]

The NMEA IN usually means the possibility to input waypoints and routes into the unit from your computer, thats part of the protocol.

I guess some units also accept position data, like the Lowrance ones seem to - at least some people seem to report that the emulator software does work with a loop cable.

//Tuomas