GPS Initialization string? - string
I'm creating a very simple application to read the info from a GPS. The information is sent on the bluetooth (COM3) in the NMEA0183 format.
Everything works good except that I can't find my position because the RMC and GGA sentence are empty. I receive other sentence with the satellite informations and positioning, but all I want is my current position (long/lat)
Here is some example of what I currently receive:
$GPZDA,,,,,,*48
$GPGGA,,,,,,,,,,,,,,*56
$GPGLL,,,,,,,*7C
$GPRMC,,,,,,,,,,,*67
$GPGST,,,,,,,,,,,,,,*57
$GPGSA,M,3,09,18,22,14,,,,,,,,,12.2,11.8,3.0*31
$GPGRS,,,,,,,,,,,,,,*51
$GPVTG,30.124,T,30.124,M,0.067,N,0.125,K*49
$GPGSV,2,1,08,22,78,283,50,18,60,137,50,14,54,281,48,09,44,052,48*7F
$GPGSV,2,2,08,46,34,212,,51,28,222,,48,12,247,,35,06,254,*74
I tried with Putty, GPS .NET 3.0.2 and my own program and the result is the same. BUT when I connect with the proprietary software called eZField, the GPS gets a fix after 20 seconds and I can see the long/lat showing. In EZField, I can't see the raw format and since it is on a pocket PC, I don't know how to sniff the bluetooth data to see if the software send any information to the GPS.
My best guest is that EZField sends some information to the GPS receiver to tell him to start sending RMC and GGA. I've read somewhere that there are "Initialization strings" that can be sent to a GPS but I can't find information about this anywhere. My GPS is a ViaSAT L1-GPS Receiver/SBAS.
Anyone can help me? :)
Thank!
It looks like your GPS doesn't have a fix yet. It is odd though that the GPS doesn't simply start searching on its own. Most initilization strings are strictly for what type of data to send back (such as the SiRFstar III proprietary format).
Pair this to your PC and run the software on it after you have started up some serial port monitoring software. That way, you can see what the init. string is, if there is one.
I use this regularly: http://www.serial-port-monitor.com/
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