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!