Hi there, skipping the mandatory compliments for your great software, let me go to the point:

I'm considering the purchase of SkyDemon and for the time being I'll be using it with the x-plane flight simulator ( http://www.x-plane.com ), I believe I'm not the only one doing serious VFR flight on a simulator and this could be an additional market opportunity for you.



Anyway, I've downloaded the demo and managed to connect it to x-plane: the simulator outputs GPS data compatible to Garmin-183 NMEA to a serial port (cit.), which I connected it to SkyDemon in navigation mode and got some results.

Latitude, longitude, track and speed are all ok, the map moves and the airplane is displayed, unfortunately the altitude data isn't shown in SD, this prevents almost all features from working and it's a deal breaker for me.

The same behavior happens on the PC navigation and on the WinCE device I've installed SD to.



The data x-plane is giving seems to be conforming to the NMEA standard, and the altitude is actually there.

This is what the program outputs, always the same 3 commands in a row (of course the data changes as the plane moves and time advances!):

$GPGGA,155123.00,4756.5368,N,01058.9329,E,1,05,0.0,2437.1,M,,,,*0D

$GPGSA,A,3,13,20,31,,,,,,,,,,02.2,02.2,*1E,*6C

$GPRMC,155123.00,A,4756.5368,N,01058.9329,E,087.8,231.8,070112,00.7,E*61\

To be sure the format was correct I've also double checked against the Sirf documentation, the chipset you are using in your MD device ( http://www.sparkfun.com/datasheets/GPS/NMEA%20Reference%20Manual1.pdf ), and also the data given as example in that manual doesn't show altitude when fed to SD:

$GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M,,,,0000*18

$GPRMC,161229.487,A,3723.2475,N,12158.3416,W,0.13,309.62,120598,,*10

I've programming skills and if you can spot what is wrong or missing there I can add myself manually for a quick test, but of course would be great if you could support this kind of data natively in SD, you'll get a new customer right away!

Sorry, above there was a typo (but I can't edit the message), there's no backslash after the third command:

$GPGGA,155123.00,4756.5368,N,01058.9329,E,1,05,0.0,2437.1,M,,,,*0D

$GPGSA,A,3,13,20,31,,,,,,,,,,02.2,02.2,*1E,*6C

$GPRMC,155123.00,A,4756.5368,N,01058.9329,E,087.8,231.8,070112,00.7,E*61

If the source is outputting altitude in the standard NMEA sentence, and also outputting a low enough vertical dilution of precision value (in whatever sentence that goes), then SkyDemon will use it.

Thanks for the reply. I will try to parse your sentence and apply the proper changes to test it



Meanwhile would be really nice of you if you could post (or PM me) a correct sequence of commands that SkyDemon can actually parse so I could use it as a reference.

...of course any other skilled user is welcome to contribute with a real GPS<->SkyDemon communication log!

I don't have a GPS log handy, but that's what you're after. The sentences output by any standard GPS device with a fix will show exactly what SkyDemon is expecting.

Ok, got it, the vertical dilution of precision is given in the GPGSA sentence, if I fake best dilution (1.0) regularly adding a sentence like this one to the X-Plane output, SkyDemon does indeed show altitude and all the other goodies:

$GPGSA,A,3,,,,,,,,,,,,,1.0,1.0,1.0*33

Do you think it makes sense to add an option to SkyDemon to show altitude information even if the dilution of precision is not good enough or not given at all?

This would make SkyPlane compatible out of the box with X-Plane and again, give you new potential customers right away!



In any case it's a pleasure to use your software: it shows attention to detail everywhere, for most of the programs I use it usually takes a minute to come up with yet another "how could they implement *that* in *this* way???!?!?!?", in SkyDemon it's a pleasure to move around.

Probably you hear it all the time, but I'm a Senior Software Engineer in Testing (or QA Head Monkey if you prefer) and my poor Devs never heard this sentence in the last 8 years or so

Thanks for the great feedback. I'm afraid we don't currently have any plans to have an option to ignore poor (or lack of) vertical DoP information from the GPS.

Well it probably does make sense to keep SD this way (safety perhaps?).



I've reported the issue to the main X-Plane developer and after a couple of emails discussing the situation we identified the problem.

X-Plane was already sending the command containing the DOP but it wasn't encoded correctly, the fix should be in the next update in a few days.



We might be very close to an out-of-the-box working solution!

Just to confirm that the output has been fixed in x-plane 10.04 beta 1, now the simulator and SkyDemon work together out of the box!

Hi,

Any ideas if this will work with skydemon app on ipad

My best,