[Xastir] Xastir on Mac and GPS

[Curt, WE7U]

On Thu, 31 Mar 2011, T Wegner wrote:

> I finally managed to get Xastir up and running on my g4 powerbook, OS X 
> 10.5.8 via a KPC 3+ (rx only at this point, tx will have to wait)
>
> I would next like to connect my garmin gps. I would like to do this by 
> connecting the gps to the second port of my usb-serial adapter.
>
> Is there a source for info on how to do this so the GPS info is routed to the 
> Xastir program for display purposes and so it will also route to the TNC (for 
> rf tx when I start working on that).

No for that 2nd part.  For the first:  Create a new Serial GPS interface in Xastir at that port.


> I did read about the HSP option; I no longer remember why I decided I didn't 
> want to go that route, but it may have something to do with using the 
> laptop/GPS in a config. w/o the TNC for route navigation.

HSP doesn't know what data is going across the serial line when it switches, so you can end up with truncated lines and concatenated pieces of different packets.

Your best setup for that equipment:  Route the GPS into the extra two pins on the KPC-3+ DE-9 connector, so the TNC gets the GPS info directly.  Then switch to using the "Serial TNC w/GPS on AUX port" interface in Xastir to talk to your TNC, and Xastir can query the TNC for the GPS string.  You'll have to set the TNC up properly to snag one of the GPS strings for its use, and that's the same string Xastir will snag periodically from the TNC (usually the GPRMC or the GPGGA string, depending on whether you want course/speed or altitude).

-- 
Curt, WE7U.        http://www.eskimo.com/~archer
APRS Device Capabilities:  http://www.eskimo.com/~archer/aprs_device_capabilities.html